/* * drivers/spi/amba-pl022.c * * A driver for the ARM PL022 PrimeCell SSP/SPI bus master. * * Copyright (C) 2008-2009 ST-Ericsson AB * Copyright (C) 2006 STMicroelectronics Pvt. Ltd. * * Author: Linus Walleij <linus.walleij@stericsson.com> * * Initial version inspired by: * linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c * Initial adoption to PL022 by: * Sachin Verma <sachin.verma@st.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ /* * TODO: * - add timeout on polled transfers * - add generic DMA framework support */ #include <linux/init.h> #include <linux/module.h> #include <linux/device.h> #include <linux/ioport.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/spi/spi.h> #include <linux/workqueue.h> #include <linux/delay.h> #include <linux/clk.h> #include <linux/err.h> #include <linux/amba/bus.h> #include <linux/amba/pl022.h> #include <linux/io.h> #include <linux/slab.h> /* * This macro is used to define some register default values. * reg is masked with mask, the OR:ed with an (again masked) * val shifted sb steps to the left. */ #define SSP_WRITE_BITS(reg, val, mask, sb) \ ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask)))) /* * This macro is also used to define some default values. * It will just shift val by sb steps to the left and mask * the result with mask. */ #define GEN_MASK_BITS(val, mask, sb) \ (((val)<<(sb)) & (mask)) #define DRIVE_TX 0 #define DO_NOT_DRIVE_TX 1 #define DO_NOT_QUEUE_DMA 0 #define QUEUE_DMA 1 #define RX_TRANSFER 1 #define TX_TRANSFER 2 /* * Macros to access SSP Registers with their offsets */ #define SSP_CR0(r) (r + 0x000) #define SSP_CR1(r) (r + 0x004) #define SSP_DR(r) (r + 0x008) #define SSP_SR(r) (r + 0x00C) #define SSP_CPSR(r) (r + 0x010) #define SSP_IMSC(r) (r + 0x014) #define SSP_RIS(r) (r + 0x018) #define SSP_MIS(r) (r + 0x01C) #define SSP_ICR(r) (r + 0x020) #define SSP_DMACR(r) (r + 0x024) #define SSP_ITCR(r) (r + 0x080) #define SSP_ITIP(r) (r + 0x084) #define SSP_ITOP(r) (r + 0x088) #define SSP_TDR(r) (r + 0x08C) #define SSP_PID0(r) (r + 0xFE0) #define SSP_PID1(r) (r + 0xFE4) #define SSP_PID2(r) (r + 0xFE8) #define SSP_PID3(r) (r + 0xFEC) #define SSP_CID0(r) (r + 0xFF0) #define SSP_CID1(r) (r + 0xFF4) #define SSP_CID2(r) (r + 0xFF8) #define SSP_CID3(r) (r + 0xFFC) /* * SSP Control Register 0 - SSP_CR0 */ #define SSP_CR0_MASK_DSS (0x0FUL << 0) #define SSP_CR0_MASK_FRF (0x3UL << 4) #define SSP_CR0_MASK_SPO (0x1UL << 6) #define SSP_CR0_MASK_SPH (0x1UL << 7) #define SSP_CR0_MASK_SCR (0xFFUL << 8) /* * The ST version of this block moves som bits * in SSP_CR0 and extends it to 32 bits */ #define SSP_CR0_MASK_DSS_ST (0x1FUL << 0) #define SSP_CR0_MASK_HALFDUP_ST (0x1UL << 5) #define SSP_CR0_MASK_CSS_ST (0x1FUL << 16) #define SSP_CR0_MASK_FRF_ST (0x3UL << 21) /* * SSP Control Register 0 - SSP_CR1 */ #define SSP_CR1_MASK_LBM (0x1UL << 0) #define SSP_CR1_MASK_SSE (0x1UL << 1) #define SSP_CR1_MASK_MS (0x1UL << 2) #define SSP_CR1_MASK_SOD (0x1UL << 3) /* * The ST version of this block adds some bits * in SSP_CR1 */ #define SSP_CR1_MASK_RENDN_ST (0x1UL << 4) #define SSP_CR1_MASK_TENDN_ST (0x1UL << 5) #define SSP_CR1_MASK_MWAIT_ST (0x1UL << 6) #define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7) #define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10) /* This one is only in the PL023 variant */ #define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13) /* * SSP Status Register - SSP_SR */ #define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */ #define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */ #define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */ #define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */ #define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */ /* * SSP Clock Prescale Register - SSP_CPSR */ #define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0) /* * SSP Interrupt Mask Set/Clear Register - SSP_IMSC */ #define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */ #define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */ #define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */ #define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */ /* * SSP Raw Interrupt Status Register - SSP_RIS */ /* Receive Overrun Raw Interrupt status */ #define SSP_RIS_MASK_RORRIS (0x1UL << 0) /* Receive Timeout Raw Interrupt status */ #define SSP_RIS_MASK_RTRIS (0x1UL << 1) /* Receive FIFO Raw Interrupt status */ #define SSP_RIS_MASK_RXRIS (0x1UL << 2) /* Transmit FIFO Raw Interrupt status */ #define SSP_RIS_MASK_TXRIS (0x1UL << 3) /* * SSP Masked Interrupt Status Register - SSP_MIS */ /* Receive Overrun Masked Interrupt status */ #define SSP_MIS_MASK_RORMIS (0x1UL << 0) /* Receive Timeout Masked Interrupt status */ #define SSP_MIS_MASK_RTMIS (0x1UL << 1) /* Receive FIFO Masked Interrupt status */ #define SSP_MIS_MASK_RXMIS (0x1UL << 2) /* Transmit FIFO Masked Interrupt status */ #define SSP_MIS_MASK_TXMIS (0x1UL << 3) /* * SSP Interrupt Clear Register - SSP_ICR */ /* Receive Overrun Raw Clear Interrupt bit */ #define SSP_ICR_MASK_RORIC (0x1UL << 0) /* Receive Timeout Clear Interrupt bit */ #define SSP_ICR_MASK_RTIC (0x1UL << 1) /* * SSP DMA Control Register - SSP_DMACR */ /* Receive DMA Enable bit */ #define SSP_DMACR_MASK_RXDMAE (0x1UL << 0) /* Transmit DMA Enable bit */ #define SSP_DMACR_MASK_TXDMAE (0x1UL << 1) /* * SSP Integration Test control Register - SSP_ITCR */ #define SSP_ITCR_MASK_ITEN (0x1UL << 0) #define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1) /* * SSP Integration Test Input Register - SSP_ITIP */ #define ITIP_MASK_SSPRXD (0x1UL << 0) #define ITIP_MASK_SSPFSSIN (0x1UL << 1) #define ITIP_MASK_SSPCLKIN (0x1UL << 2) #define ITIP_MASK_RXDMAC (0x1UL << 3) #define ITIP_MASK_TXDMAC (0x1UL << 4) #define ITIP_MASK_SSPTXDIN (0x1UL << 5) /* * SSP Integration Test output Register - SSP_ITOP */ #define ITOP_MASK_SSPTXD (0x1UL << 0) #define ITOP_MASK_SSPFSSOUT (0x1UL << 1) #define ITOP_MASK_SSPCLKOUT (0x1UL << 2) #define ITOP_MASK_SSPOEn (0x1UL << 3) #define ITOP_MASK_SSPCTLOEn (0x1UL << 4) #define ITOP_MASK_RORINTR (0x1UL << 5) #define ITOP_MASK_RTINTR (0x1UL << 6) #define ITOP_MASK_RXINTR (0x1UL << 7) #define ITOP_MASK_TXINTR (0x1UL << 8) #define ITOP_MASK_INTR (0x1UL << 9) #define ITOP_MASK_RXDMABREQ (0x1UL << 10) #define ITOP_MASK_RXDMASREQ (0x1UL << 11) #define ITOP_MASK_TXDMABREQ (0x1UL << 12) #define ITOP_MASK_TXDMASREQ (0x1UL << 13) /* * SSP Test Data Register - SSP_TDR */ #define TDR_MASK_TESTDATA (0xFFFFFFFF) /* * Message State * we use the spi_message.state (void *) pointer to * hold a single state value, that's why all this * (void *) casting is done here. */ #define STATE_START ((void *) 0) #define STATE_RUNNING ((void *) 1) #define STATE_DONE ((void *) 2) #define STATE_ERROR ((void *) -1) /* * Queue State */ #define QUEUE_RUNNING (0) #define QUEUE_STOPPED (1) /* * SSP State - Whether Enabled or Disabled */ #define SSP_DISABLED (0) #define SSP_ENABLED (1) /* * SSP DMA State - Whether DMA Enabled or Disabled */ #define SSP_DMA_DISABLED (0) #define SSP_DMA_ENABLED (1) /* * SSP Clock Defaults */ #define SSP_DEFAULT_CLKRATE 0x2 #define SSP_DEFAULT_PRESCALE 0x40 /* * SSP Clock Parameter ranges */ #define CPSDVR_MIN 0x02 #define CPSDVR_MAX 0xFE #define SCR_MIN 0x00 #define SCR_MAX 0xFF /* * SSP Interrupt related Macros */ #define DEFAULT_SSP_REG_IMSC 0x0UL #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC #define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC) #define CLEAR_ALL_INTERRUPTS 0x3 /* * The type of reading going on on this chip */ enum ssp_reading { READING_NULL, READING_U8, READING_U16, READING_U32 }; /** * The type of writing going on on this chip */ enum ssp_writing { WRITING_NULL, WRITING_U8, WRITING_U16, WRITING_U32 }; /** * struct vendor_data - vendor-specific config parameters * for PL022 derivates * @fifodepth: depth of FIFOs (both) * @max_bpw: maximum number of bits per word * @unidir: supports unidirection transfers * @extended_cr: 32 bit wide control register 0 with extra * features and extra features in CR1 as found in the ST variants * @pl023: supports a subset of the ST extensions called "PL023" */ struct vendor_data { int fifodepth; int max_bpw; bool unidir; bool extended_cr; bool pl023; }; /** * struct pl022 - This is the private SSP driver data structure * @adev: AMBA device model hookup * @vendor: Vendor data for the IP block * @phybase: The physical memory where the SSP device resides * @virtbase: The virtual memory where the SSP is mapped * @master: SPI framework hookup * @master_info: controller-specific data from machine setup * @regs: SSP controller register's virtual address * @pump_messages: Work struct for scheduling work to the workqueue * @lock: spinlock to syncronise access to driver data * @workqueue: a workqueue on which any spi_message request is queued * @busy: workqueue is busy * @run: workqueue is running * @pump_transfers: Tasklet used in Interrupt Transfer mode * @cur_msg: Pointer to current spi_message being processed * @cur_transfer: Pointer to current spi_transfer * @cur_chip: pointer to current clients chip(assigned from controller_state) * @tx: current position in TX buffer to be read * @tx_end: end position in TX buffer to be read * @rx: current position in RX buffer to be written * @rx_end: end position in RX buffer to be written * @readingtype: the type of read currently going on * @writingtype: the type or write currently going on */ struct pl022 { struct amba_device *adev; struct vendor_data *vendor; resource_size_t phybase; void __iomem *virtbase; struct clk *clk; struct spi_master *master; struct pl022_ssp_controller *master_info; /* Driver message queue */ struct workqueue_struct *workqueue; struct work_struct pump_messages; spinlock_t queue_lock; struct list_head queue; int busy; int run; /* Message transfer pump */ struct tasklet_struct pump_transfers; struct spi_message *cur_msg; struct spi_transfer *cur_transfer; struct chip_data *cur_chip; void *tx; void *tx_end; void *rx; void *rx_end; enum ssp_reading read; enum ssp_writing write; u32 exp_fifo_level; }; /** * struct chip_data - To maintain runtime state of SSP for each client chip * @cr0: Value of control register CR0 of SSP - on later ST variants this * register is 32 bits wide rather than just 16 * @cr1: Value of control register CR1 of SSP * @dmacr: Value of DMA control Register of SSP * @cpsr: Value of Clock prescale register * @n_bytes: how many bytes(power of 2) reqd for a given data width of client * @enable_dma: Whether to enable DMA or not * @write: function ptr to be used to write when doing xfer for this chip * @read: function ptr to be used to read when doing xfer for this chip * @cs_control: chip select callback provided by chip * @xfer_type: polling/interrupt/DMA * * Runtime state of the SSP controller, maintained per chip, * This would be set according to the current message that would be served */ struct chip_data { u32 cr0; u16 cr1; u16 dmacr; u16 cpsr; u8 n_bytes; u8 enable_dma:1; enum ssp_reading read; enum ssp_writing write; void (*cs_control) (u32 command); int xfer_type; }; /** * null_cs_control - Dummy chip select function * @command: select/delect the chip * * If no chip select function is provided by client this is used as dummy * chip select */ static void null_cs_control(u32 command) { pr_debug("pl022: dummy chip select control, CS=0x%x\n", command); } /** * giveback - current spi_message is over, schedule next message and call * callback of this message. Assumes that caller already * set message->status; dma and pio irqs are blocked * @pl022: SSP driver private data structure */ static void giveback(struct pl022 *pl022) { struct spi_transfer *last_transfer; unsigned long flags; struct spi_message *msg; void (*curr_cs_control) (u32 command); /* * This local reference to the chip select function * is needed because we set curr_chip to NULL * as a step toward termininating the message. */ curr_cs_control = pl022->cur_chip->cs_control; spin_lock_irqsave(&pl022->queue_lock, flags); msg = pl022->cur_msg; pl022->cur_msg = NULL; pl022->cur_transfer = NULL; pl022->cur_chip = NULL; queue_work(pl022->workqueue, &pl022->pump_messages); spin_unlock_irqrestore(&pl022->queue_lock, flags); last_transfer = list_entry(msg->transfers.prev, struct spi_transfer, transfer_list); /* Delay if requested before any change in chip select */ if (last_transfer->delay_usecs) /* * FIXME: This runs in interrupt context. * Is this really smart? */ udelay(last_transfer->delay_usecs); /* * Drop chip select UNLESS cs_change is true or we are returning * a message with an error, or next message is for another chip */ if (!last_transfer->cs_change) curr_cs_control(SSP_CHIP_DESELECT); else { struct spi_message *next_msg; /* Holding of cs was hinted, but we need to make sure * the next message is for the same chip. Don't waste * time with the following tests unless this was hinted. * * We cannot postpone this until pump_messages, because * after calling msg->complete (below) the driver that * sent the current message could be unloaded, which * could invalidate the cs_control() callback... */ /* get a pointer to the next message, if any */ spin_lock_irqsave(&pl022->queue_lock, flags); if (list_empty(&pl022->queue)) next_msg = NULL; else next_msg = list_entry(pl022->queue.next, struct spi_message, queue); spin_unlock_irqrestore(&pl022->queue_lock, flags); /* see if the next and current messages point * to the same chip */ if (next_msg && next_msg->spi != msg->spi) next_msg = NULL; if (!next_msg || msg->state == STATE_ERROR) curr_cs_control(SSP_CHIP_DESELECT); } msg->state = NULL; if (msg->complete) msg->complete(msg->context); /* This message is completed, so let's turn off the clock! */ clk_disable(pl022->clk); } /** * flush - flush the FIFO to reach a clean state * @pl022: SSP driver private data structure */ static int flush(struct pl022 *pl022) { unsigned long limit = loops_per_jiffy << 1; dev_dbg(&pl022->adev->dev, "flush\n"); do { while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) readw(SSP_DR(pl022->virtbase)); } while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--); pl022->exp_fifo_level = 0; return limit; } /** * restore_state - Load configuration of current chip * @pl022: SSP driver private data structure */ static void restore_state(struct pl022 *pl022) { struct chip_data *chip = pl022->cur_chip; if (pl022->vendor->extended_cr) writel(chip->cr0, SSP_CR0(pl022->virtbase)); else writew(chip->cr0, SSP_CR0(pl022->virtbase)); writew(chip->cr1, SSP_CR1(pl022->virtbase)); writew(chip->dmacr, SSP_DMACR(pl022->virtbase)); writew(chip->cpsr, SSP_CPSR(pl022->virtbase)); writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); } /* * Default SSP Register Values */ #define DEFAULT_SSP_REG_CR0 ( \ GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \ GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \ GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \ GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \ GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \ ) /* ST versions have slightly different bit layout */ #define DEFAULT_SSP_REG_CR0_ST ( \ GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \ GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \ GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \ GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \ GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \ GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16) | \ GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \ ) /* The PL023 version is slightly different again */ #define DEFAULT_SSP_REG_CR0_ST_PL023 ( \ GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \ GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \ GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \ GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \ ) #define DEFAULT_SSP_REG_CR1 ( \ GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \ GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \ GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \ GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \ ) /* ST versions extend this register to use all 16 bits */ #define DEFAULT_SSP_REG_CR1_ST ( \ DEFAULT_SSP_REG_CR1 | \ GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \ GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \ GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\ GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \ GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \ ) /* * The PL023 variant has further differences: no loopback mode, no microwire * support, and a new clock feedback delay setting. */ #define DEFAULT_SSP_REG_CR1_ST_PL023 ( \ GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \ GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \ GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \ GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \ GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \ GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \ GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \ GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \ ) #define DEFAULT_SSP_REG_CPSR ( \ GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \ ) #define DEFAULT_SSP_REG_DMACR (\ GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \ GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \ ) /** * load_ssp_default_config - Load default configuration for SSP * @pl022: SSP driver private data structure */ static void load_ssp_default_config(struct pl022 *pl022) { if (pl022->vendor->pl023) { writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase)); writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase)); } else if (pl022->vendor->extended_cr) { writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase)); writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase)); } else { writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase)); writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase)); } writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase)); writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase)); writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); } /** * This will write to TX and read from RX according to the parameters * set in pl022. */ static void readwriter(struct pl022 *pl022) { /* * The FIFO depth is different inbetween primecell variants. * I believe filling in too much in the FIFO might cause * errons in 8bit wide transfers on ARM variants (just 8 words * FIFO, means only 8x8 = 64 bits in FIFO) at least. * * To prevent this issue, the TX FIFO is only filled to the * unused RX FIFO fill length, regardless of what the TX * FIFO status flag indicates. */ dev_dbg(&pl022->adev->dev, "%s, rx: %p, rxend: %p, tx: %p, txend: %p\n", __func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end); /* Read as much as you can */ while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) && (pl022->rx < pl022->rx_end)) { switch (pl022->read) { case READING_NULL: readw(SSP_DR(pl022->virtbase)); break; case READING_U8: *(u8 *) (pl022->rx) = readw(SSP_DR(pl022->virtbase)) & 0xFFU; break; case READING_U16: *(u16 *) (pl022->rx) = (u16) readw(SSP_DR(pl022->virtbase)); break; case READING_U32: *(u32 *) (pl022->rx) = readl(SSP_DR(pl022->virtbase)); break; } pl022->rx += (pl022->cur_chip->n_bytes); pl022->exp_fifo_level--; } /* * Write as much as possible up to the RX FIFO size */ while ((pl022->exp_fifo_level < pl022->vendor->fifodepth) && (pl022->tx < pl022->tx_end)) { switch (pl022->write) { case WRITING_NULL: writew(0x0, SSP_DR(pl022->virtbase)); break; case WRITING_U8: writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase)); break; case WRITING_U16: writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase)); break; case WRITING_U32: writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase)); break; } pl022->tx += (pl022->cur_chip->n_bytes); pl022->exp_fifo_level++; /* * This inner reader takes care of things appearing in the RX * FIFO as we're transmitting. This will happen a lot since the * clock starts running when you put things into the TX FIFO, * and then things are continously clocked into the RX FIFO. */ while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE) && (pl022->rx < pl022->rx_end)) { switch (pl022->read) { case READING_NULL: readw(SSP_DR(pl022->virtbase)); break; case READING_U8: *(u8 *) (pl022->rx) = readw(SSP_DR(pl022->virtbase)) & 0xFFU; break; case READING_U16: *(u16 *) (pl022->rx) = (u16) readw(SSP_DR(pl022->virtbase)); break; case READING_U32: *(u32 *) (pl022->rx) = readl(SSP_DR(pl022->virtbase)); break; } pl022->rx += (pl022->cur_chip->n_bytes); pl022->exp_fifo_level--; } } /* * When we exit here the TX FIFO should be full and the RX FIFO * should be empty */ } /** * next_transfer - Move to the Next transfer in the current spi message * @pl022: SSP driver private data structure * * This function moves though the linked list of spi transfers in the * current spi message and returns with the state of current spi * message i.e whether its last transfer is done(STATE_DONE) or * Next transfer is ready(STATE_RUNNING) */ static void *next_transfer(struct pl022 *pl022) { struct spi_message *msg = pl022->cur_msg; struct spi_transfer *trans = pl022->cur_transfer; /* Move to next transfer */ if (trans->transfer_list.next != &msg->transfers) { pl022->cur_transfer = list_entry(trans->transfer_list.next, struct spi_transfer, transfer_list); return STATE_RUNNING; } return STATE_DONE; } /** * pl022_interrupt_handler - Interrupt handler for SSP controller * * This function handles interrupts generated for an interrupt based transfer. * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the * current message's state as STATE_ERROR and schedule the tasklet * pump_transfers which will do the postprocessing of the current message by * calling giveback(). Otherwise it reads data from RX FIFO till there is no * more data, and writes data in TX FIFO till it is not full. If we complete * the transfer we move to the next transfer and schedule the tasklet. */ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) { struct pl022 *pl022 = dev_id; struct spi_message *msg = pl022->cur_msg; u16 irq_status = 0; u16 flag = 0; if (unlikely(!msg)) { dev_err(&pl022->adev->dev, "bad message state in interrupt handler"); /* Never fail */ return IRQ_HANDLED; } /* Read the Interrupt Status Register */ irq_status = readw(SSP_MIS(pl022->virtbase)); if (unlikely(!irq_status)) return IRQ_NONE; /* This handles the error code interrupts */ if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) { /* * Overrun interrupt - bail out since our Data has been * corrupted */ dev_err(&pl022->adev->dev, "FIFO overrun\n"); if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF) dev_err(&pl022->adev->dev, "RXFIFO is full\n"); if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF) dev_err(&pl022->adev->dev, "TXFIFO is full\n"); /* * Disable and clear interrupts, disable SSP, * mark message with bad status so it can be * retried. */ writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase)); msg->state = STATE_ERROR; /* Schedule message queue handler */ tasklet_schedule(&pl022->pump_transfers); return IRQ_HANDLED; } readwriter(pl022); if ((pl022->tx == pl022->tx_end) && (flag == 0)) { flag = 1; /* Disable Transmit interrupt */ writew(readw(SSP_IMSC(pl022->virtbase)) & (~SSP_IMSC_MASK_TXIM), SSP_IMSC(pl022->virtbase)); } /* * Since all transactions must write as much as shall be read, * we can conclude the entire transaction once RX is complete. * At this point, all TX will always be finished. */ if (pl022->rx >= pl022->rx_end) { writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase)); if (unlikely(pl022->rx > pl022->rx_end)) { dev_warn(&pl022->adev->dev, "read %u surplus " "bytes (did you request an odd " "number of bytes on a 16bit bus?)\n", (u32) (pl022->rx - pl022->rx_end)); } /* Update total bytes transfered */ msg->actual_length += pl022->cur_transfer->len; if (pl022->cur_transfer->cs_change) pl022->cur_chip-> cs_control(SSP_CHIP_DESELECT); /* Move to next transfer */ msg->state = next_transfer(pl022); tasklet_schedule(&pl022->pump_transfers); return IRQ_HANDLED; } return IRQ_HANDLED; } /** * This sets up the pointers to memory for the next message to * send out on the SPI bus. */ static int set_up_next_transfer(struct pl022 *pl022, struct spi_transfer *transfer) { int residue; /* Sanity check the message for this bus width */ residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes; if (unlikely(residue != 0)) { dev_err(&pl022->adev->dev, "message of %u bytes to transmit but the current " "chip bus has a data width of %u bytes!\n", pl022->cur_transfer->len, pl022->cur_chip->n_bytes); dev_err(&pl022->adev->dev, "skipping this message\n"); return -EIO; } pl022->tx = (void *)transfer->tx_buf; pl022->tx_end = pl022->tx + pl022->cur_transfer->len; pl022->rx = (void *)transfer->rx_buf; pl022->rx_end = pl022->rx + pl022->cur_transfer->len; pl022->write = pl022->tx ? pl022->cur_chip->write : WRITING_NULL; pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL; return 0; } /** * pump_transfers - Tasklet function which schedules next interrupt transfer * when running in interrupt transfer mode. * @data: SSP driver private data structure * */ static void pump_transfers(unsigned long data) { struct pl022 *pl022 = (struct pl022 *) data; struct spi_message *message = NULL; struct spi_transfer *transfer = NULL; struct spi_transfer *previous = NULL; /* Get current state information */ message = pl022->cur_msg; transfer = pl022->cur_transfer; /* Handle for abort */ if (message->state == STATE_ERROR) { message->status = -EIO; giveback(pl022); return; } /* Handle end of message */ if (message->state == STATE_DONE) { message->status = 0; giveback(pl022); return; } /* Delay if requested at end of transfer before CS change */ if (message->state == STATE_RUNNING) { previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list); if (previous->delay_usecs) /* * FIXME: This runs in interrupt context. * Is this really smart? */ udelay(previous->delay_usecs); /* Drop chip select only if cs_change is requested */ if (previous->cs_change) pl022->cur_chip->cs_control(SSP_CHIP_SELECT); } else { /* STATE_START */ message->state = STATE_RUNNING; } if (set_up_next_transfer(pl022, transfer)) { message->state = STATE_ERROR; message->status = -EIO; giveback(pl022); return; } /* Flush the FIFOs and let's go! */ flush(pl022); writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); } /** * NOT IMPLEMENTED * configure_dma - It configures the DMA pipes for DMA transfers * @data: SSP driver's private data structure * */ static int configure_dma(void *data) { struct pl022 *pl022 = data; dev_dbg(&pl022->adev->dev, "configure DMA\n"); return -ENOTSUPP; } /** * do_dma_transfer - It handles transfers of the current message * if it is DMA xfer. * NOT FULLY IMPLEMENTED * @data: SSP driver's private data structure */ static void do_dma_transfer(void *data) { struct pl022 *pl022 = data; if (configure_dma(data)) { dev_dbg(&pl022->adev->dev, "configuration of DMA Failed!\n"); goto err_config_dma; } /* TODO: Implememt DMA setup of pipes here */ /* Enable target chip, set up transfer */ pl022->cur_chip->cs_control(SSP_CHIP_SELECT); if (set_up_next_transfer(pl022, pl022->cur_transfer)) { /* Error path */ pl022->cur_msg->state = STATE_ERROR; pl022->cur_msg->status = -EIO; giveback(pl022); return; } /* Enable SSP */ writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), SSP_CR1(pl022->virtbase)); /* TODO: Enable the DMA transfer here */ return; err_config_dma: pl022->cur_msg->state = STATE_ERROR; pl022->cur_msg->status = -EIO; giveback(pl022); return; } static void do_interrupt_transfer(void *data) { struct pl022 *pl022 = data; /* Enable target chip */ pl022->cur_chip->cs_control(SSP_CHIP_SELECT); if (set_up_next_transfer(pl022, pl022->cur_transfer)) { /* Error path */ pl022->cur_msg->state = STATE_ERROR; pl022->cur_msg->status = -EIO; giveback(pl022); return; } /* Enable SSP, turn on interrupts */ writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), SSP_CR1(pl022->virtbase)); writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase)); } static void do_polling_transfer(void *data) { struct pl022 *pl022 = data; struct spi_message *message = NULL; struct spi_transfer *transfer = NULL; struct spi_transfer *previous = NULL; struct chip_data *chip; chip = pl022->cur_chip; message = pl022->cur_msg; while (message->state != STATE_DONE) { /* Handle for abort */ if (message->state == STATE_ERROR) break; transfer = pl022->cur_transfer; /* Delay if requested at end of transfer */ if (message->state == STATE_RUNNING) { previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list); if (previous->delay_usecs) udelay(previous->delay_usecs); if (previous->cs_change) pl022->cur_chip->cs_control(SSP_CHIP_SELECT); } else { /* STATE_START */ message->state = STATE_RUNNING; pl022->cur_chip->cs_control(SSP_CHIP_SELECT); } /* Configuration Changing Per Transfer */ if (set_up_next_transfer(pl022, transfer)) { /* Error path */ message->state = STATE_ERROR; break; } /* Flush FIFOs and enable SSP */ flush(pl022); writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE), SSP_CR1(pl022->virtbase)); dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n"); /* FIXME: insert a timeout so we don't hang here indefinately */ while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) readwriter(pl022); /* Update total byte transfered */ message->actual_length += pl022->cur_transfer->len; if (pl022->cur_transfer->cs_change) pl022->cur_chip->cs_control(SSP_CHIP_DESELECT); /* Move to next transfer */ message->state = next_transfer(pl022); } /* Handle end of message */ if (message->state == STATE_DONE) message->status = 0; else message->status = -EIO; giveback(pl022); return; } /** * pump_messages - Workqueue function which processes spi message queue * @data: pointer to private data of SSP driver * * This function checks if there is any spi message in the queue that * needs processing and delegate control to appropriate function * do_polling_transfer()/do_interrupt_transfer()/do_dma_transfer() * based on the kind of the transfer * */ static void pump_messages(struct work_struct *work) { struct pl022 *pl022 = container_of(work, struct pl022, pump_messages); unsigned long flags; /* Lock queue and check for queue work */ spin_lock_irqsave(&pl022->queue_lock, flags); if (list_empty(&pl022->queue) || pl022->run == QUEUE_STOPPED) { pl022->busy = 0; spin_unlock_irqrestore(&pl022->queue_lock, flags); return; } /* Make sure we are not already running a message */ if (pl022->cur_msg) { spin_unlock_irqrestore(&pl022->queue_lock, flags); return; } /* Extract head of queue */ pl022->cur_msg = list_entry(pl022->queue.next, struct spi_message, queue); list_del_init(&pl022->cur_msg->queue); pl022->busy = 1; spin_unlock_irqrestore(&pl022->queue_lock, flags); /* Initial message state */ pl022->cur_msg->state = STATE_START; pl022->cur_transfer = list_entry(pl022->cur_msg->transfers.next, struct spi_transfer, transfer_list); /* Setup the SPI using the per chip configuration */ pl022->cur_chip = spi_get_ctldata(pl022->cur_msg->spi); /* * We enable the clock here, then the clock will be disabled when * giveback() is called in each method (poll/interrupt/DMA) */ clk_enable(pl022->clk); restore_state(pl022); flush(pl022); if (pl022->cur_chip->xfer_type == POLLING_TRANSFER) do_polling_transfer(pl022); else if (pl022->cur_chip->xfer_type == INTERRUPT_TRANSFER) do_interrupt_transfer(pl022); else do_dma_transfer(pl022); } static int __init init_queue(struct pl022 *pl022) { INIT_LIST_HEAD(&pl022->queue); spin_lock_init(&pl022->queue_lock); pl022->run = QUEUE_STOPPED; pl022->busy = 0; tasklet_init(&pl022->pump_transfers, pump_transfers, (unsigned long)pl022); INIT_WORK(&pl022->pump_messages, pump_messages); pl022->workqueue = create_singlethread_workqueue( dev_name(pl022->master->dev.parent)); if (pl022->workqueue == NULL) return -EBUSY; return 0; } static int start_queue(struct pl022 *pl022) { unsigned long flags; spin_lock_irqsave(&pl022->queue_lock, flags); if (pl022->run == QUEUE_RUNNING || pl022->busy) { spin_unlock_irqrestore(&pl022->queue_lock, flags); return -EBUSY; } pl022->run = QUEUE_RUNNING; pl022->cur_msg = NULL; pl022->cur_transfer = NULL; pl022->cur_chip = NULL; spin_unlock_irqrestore(&pl022->queue_lock, flags); queue_work(pl022->workqueue, &pl022->pump_messages); return 0; } static int stop_queue(struct pl022 *pl022) { unsigned long flags; unsigned limit = 500; int status = 0; spin_lock_irqsave(&pl022->queue_lock, flags); /* This is a bit lame, but is optimized for the common execution path. * A wait_queue on the pl022->busy could be used, but then the common * execution path (pump_messages) would be required to call wake_up or * friends on every SPI message. Do this instead */ while (!list_empty(&pl022->queue) && pl022->busy && limit--) { spin_unlock_irqrestore(&pl022->queue_lock, flags); msleep(10); spin_lock_irqsave(&pl022->queue_lock, flags); } if (!list_empty(&pl022->queue) || pl022->busy) status = -EBUSY; else pl022->run = QUEUE_STOPPED; spin_unlock_irqrestore(&pl022->queue_lock, flags); return status; } static int destroy_queue(struct pl022 *pl022) { int status; status = stop_queue(pl022); /* we are unloading the module or failing to load (only two calls * to this routine), and neither call can handle a return value. * However, destroy_workqueue calls flush_workqueue, and that will * block until all work is done. If the reason that stop_queue * timed out is that the work will never finish, then it does no * good to call destroy_workqueue, so return anyway. */ if (status != 0) return status; destroy_workqueue(pl022->workqueue); return 0; } static int verify_controller_parameters(struct pl022 *pl022, struct pl022_config_chip *chip_info) { if ((chip_info->lbm != LOOPBACK_ENABLED) && (chip_info->lbm != LOOPBACK_DISABLED)) { dev_err(chip_info->dev, "loopback Mode is configured incorrectly\n"); return -EINVAL; } if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI) || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) { dev_err(chip_info->dev, "interface is configured incorrectly\n"); return -EINVAL; } if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) && (!pl022->vendor->unidir)) { dev_err(chip_info->dev, "unidirectional mode not supported in this " "hardware version\n"); return -EINVAL; } if ((chip_info->hierarchy != SSP_MASTER) && (chip_info->hierarchy != SSP_SLAVE)) { dev_err(chip_info->dev, "hierarchy is configured incorrectly\n"); return -EINVAL; } if (((chip_info->clk_freq).cpsdvsr < CPSDVR_MIN) || ((chip_info->clk_freq).cpsdvsr > CPSDVR_MAX)) { dev_err(chip_info->dev, "cpsdvsr is configured incorrectly\n"); return -EINVAL; } if ((chip_info->endian_rx != SSP_RX_MSB) && (chip_info->endian_rx != SSP_RX_LSB)) { dev_err(chip_info->dev, "RX FIFO endianess is configured incorrectly\n"); return -EINVAL; } if ((chip_info->endian_tx != SSP_TX_MSB) && (chip_info->endian_tx != SSP_TX_LSB)) { dev_err(chip_info->dev, "TX FIFO endianess is configured incorrectly\n"); return -EINVAL; } if ((chip_info->data_size < SSP_DATA_BITS_4) || (chip_info->data_size > SSP_DATA_BITS_32)) { dev_err(chip_info->dev, "DATA Size is configured incorrectly\n"); return -EINVAL; } if ((chip_info->com_mode != INTERRUPT_TRANSFER) && (chip_info->com_mode != DMA_TRANSFER) && (chip_info->com_mode != POLLING_TRANSFER)) { dev_err(chip_info->dev, "Communication mode is configured incorrectly\n"); return -EINVAL; } if ((chip_info->rx_lev_trig < SSP_RX_1_OR_MORE_ELEM) || (chip_info->rx_lev_trig > SSP_RX_32_OR_MORE_ELEM)) { dev_err(chip_info->dev, "RX FIFO Trigger Level is configured incorrectly\n"); return -EINVAL; } if ((chip_info->tx_lev_trig < SSP_TX_1_OR_MORE_EMPTY_LOC) || (chip_info->tx_lev_trig > SSP_TX_32_OR_MORE_EMPTY_LOC)) { dev_err(chip_info->dev, "TX FIFO Trigger Level is configured incorrectly\n"); return -EINVAL; } if (chip_info->iface == SSP_INTERFACE_MOTOROLA_SPI) { if ((chip_info->clk_phase != SSP_CLK_FIRST_EDGE) && (chip_info->clk_phase != SSP_CLK_SECOND_EDGE)) { dev_err(chip_info->dev, "Clock Phase is configured incorrectly\n"); return -EINVAL; } if ((chip_info->clk_pol != SSP_CLK_POL_IDLE_LOW) && (chip_info->clk_pol != SSP_CLK_POL_IDLE_HIGH)) { dev_err(chip_info->dev, "Clock Polarity is configured incorrectly\n"); return -EINVAL; } } if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) { if ((chip_info->ctrl_len < SSP_BITS_4) || (chip_info->ctrl_len > SSP_BITS_32)) { dev_err(chip_info->dev, "CTRL LEN is configured incorrectly\n"); return -EINVAL; } if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO) && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) { dev_err(chip_info->dev, "Wait State is configured incorrectly\n"); return -EINVAL; } /* Half duplex is only available in the ST Micro version */ if (pl022->vendor->extended_cr) { if ((chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX) && (chip_info->duplex != SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) dev_err(chip_info->dev, "Microwire duplex mode is configured incorrectly\n"); return -EINVAL; } else { if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX) dev_err(chip_info->dev, "Microwire half duplex mode requested," " but this is only available in the" " ST version of PL022\n"); return -EINVAL; } } if (chip_info->cs_control == NULL) { dev_warn(chip_info->dev, "Chip Select Function is NULL for this chip\n"); chip_info->cs_control = null_cs_control; } return 0; } /** * pl022_transfer - transfer function registered to SPI master framework * @spi: spi device which is requesting transfer * @msg: spi message which is to handled is queued to driver queue * * This function is registered to the SPI framework for this SPI master * controller. It will queue the spi_message in the queue of driver if * the queue is not stopped and return. */ static int pl022_transfer(struct spi_device *spi, struct spi_message *msg) { struct pl022 *pl022 = spi_master_get_devdata(spi->master); unsigned long flags; spin_lock_irqsave(&pl022->queue_lock, flags); if (pl022->run == QUEUE_STOPPED) { spin_unlock_irqrestore(&pl022->queue_lock, flags); return -ESHUTDOWN; } msg->actual_length = 0; msg->status = -EINPROGRESS; msg->state = STATE_START; list_add_tail(&msg->queue, &pl022->queue); if (pl022->run == QUEUE_RUNNING && !pl022->busy) queue_work(pl022->workqueue, &pl022->pump_messages); spin_unlock_irqrestore(&pl022->queue_lock, flags); return 0; } static int calculate_effective_freq(struct pl022 *pl022, int freq, struct ssp_clock_params *clk_freq) { /* Lets calculate the frequency parameters */ u16 cpsdvsr = 2; u16 scr = 0; bool freq_found = false; u32 rate; u32 max_tclk; u32 min_tclk; rate = clk_get_rate(pl022->clk); /* cpsdvscr = 2 & scr 0 */ max_tclk = (rate / (CPSDVR_MIN * (1 + SCR_MIN))); /* cpsdvsr = 254 & scr = 255 */ min_tclk = (rate / (CPSDVR_MAX * (1 + SCR_MAX))); if ((freq <= max_tclk) && (freq >= min_tclk)) { while (cpsdvsr <= CPSDVR_MAX && !freq_found) { while (scr <= SCR_MAX && !freq_found) { if ((rate / (cpsdvsr * (1 + scr))) > freq) scr += 1; else { /* * This bool is made true when * effective frequency >= * target frequency is found */ freq_found = true; if ((rate / (cpsdvsr * (1 + scr))) != freq) { if (scr == SCR_MIN) { cpsdvsr -= 2; scr = SCR_MAX; } else scr -= 1; } } } if (!freq_found) { cpsdvsr += 2; scr = SCR_MIN; } } if (cpsdvsr != 0) { dev_dbg(&pl022->adev->dev, "SSP Effective Frequency is %u\n", (rate / (cpsdvsr * (1 + scr)))); clk_freq->cpsdvsr = (u8) (cpsdvsr & 0xFF); clk_freq->scr = (u8) (scr & 0xFF); dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n", clk_freq->cpsdvsr, clk_freq->scr); } } else { dev_err(&pl022->adev->dev, "controller data is incorrect: out of range frequency"); return -EINVAL; } return 0; } /** * NOT IMPLEMENTED * process_dma_info - Processes the DMA info provided by client drivers * @chip_info: chip info provided by client device * @chip: Runtime state maintained by the SSP controller for each spi device * * This function processes and stores DMA config provided by client driver * into the runtime state maintained by the SSP controller driver */ static int process_dma_info(struct pl022_config_chip *chip_info, struct chip_data *chip) { dev_err(chip_info->dev, "cannot process DMA info, DMA not implemented!\n"); return -ENOTSUPP; } /** * pl022_setup - setup function registered to SPI master framework * @spi: spi device which is requesting setup * * This function is registered to the SPI framework for this SPI master * controller. If it is the first time when setup is called by this device, * this function will initialize the runtime state for this chip and save * the same in the device structure. Else it will update the runtime info * with the updated chip info. Nothing is really being written to the * controller hardware here, that is not done until the actual transfer * commence. */ /* FIXME: JUST GUESSING the spi->mode bits understood by this driver */ #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \ | SPI_LSB_FIRST | SPI_LOOP) static int pl022_setup(struct spi_device *spi) { struct pl022_config_chip *chip_info; struct chip_data *chip; int status = 0; struct pl022 *pl022 = spi_master_get_devdata(spi->master); if (spi->mode & ~MODEBITS) { dev_dbg(&spi->dev, "unsupported mode bits %x\n", spi->mode & ~MODEBITS); return -EINVAL; } if (!spi->max_speed_hz) return -EINVAL; /* Get controller_state if one is supplied */ chip = spi_get_ctldata(spi); if (chip == NULL) { chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); if (!chip) { dev_err(&spi->dev, "cannot allocate controller state\n"); return -ENOMEM; } dev_dbg(&spi->dev, "allocated memory for controller's runtime state\n"); } /* Get controller data if one is supplied */ chip_info = spi->controller_data; if (chip_info == NULL) { /* spi_board_info.controller_data not is supplied */ dev_dbg(&spi->dev, "using default controller_data settings\n"); chip_info = kzalloc(sizeof(struct pl022_config_chip), GFP_KERNEL); if (!chip_info) { dev_err(&spi->dev, "cannot allocate controller data\n"); status = -ENOMEM; goto err_first_setup; } dev_dbg(&spi->dev, "allocated memory for controller data\n"); /* Pointer back to the SPI device */ chip_info->dev = &spi->dev; /* * Set controller data default values: * Polling is supported by default */ chip_info->lbm = LOOPBACK_DISABLED; chip_info->com_mode = POLLING_TRANSFER; chip_info->iface = SSP_INTERFACE_MOTOROLA_SPI; chip_info->hierarchy = SSP_SLAVE; chip_info->slave_tx_disable = DO_NOT_DRIVE_TX; chip_info->endian_tx = SSP_TX_LSB; chip_info->endian_rx = SSP_RX_LSB; chip_info->data_size = SSP_DATA_BITS_12; chip_info->rx_lev_trig = SSP_RX_1_OR_MORE_ELEM; chip_info->tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC; chip_info->clk_phase = SSP_CLK_SECOND_EDGE; chip_info->clk_pol = SSP_CLK_POL_IDLE_LOW; chip_info->ctrl_len = SSP_BITS_8; chip_info->wait_state = SSP_MWIRE_WAIT_ZERO; chip_info->duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX; chip_info->cs_control = null_cs_control; } else { dev_dbg(&spi->dev, "using user supplied controller_data settings\n"); } /* * We can override with custom divisors, else we use the board * frequency setting */ if ((0 == chip_info->clk_freq.cpsdvsr) && (0 == chip_info->clk_freq.scr)) { status = calculate_effective_freq(pl022, spi->max_speed_hz, &chip_info->clk_freq); if (status < 0) goto err_config_params; } else { if ((chip_info->clk_freq.cpsdvsr % 2) != 0) chip_info->clk_freq.cpsdvsr = chip_info->clk_freq.cpsdvsr - 1; } status = verify_controller_parameters(pl022, chip_info); if (status) { dev_err(&spi->dev, "controller data is incorrect"); goto err_config_params; } /* Now set controller state based on controller data */ chip->xfer_type = chip_info->com_mode; chip->cs_control = chip_info->cs_control; if (chip_info->data_size <= 8) { dev_dbg(&spi->dev, "1 <= n <=8 bits per word\n"); chip->n_bytes = 1; chip->read = READING_U8; chip->write = WRITING_U8; } else if (chip_info->data_size <= 16) { dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n"); chip->n_bytes = 2; chip->read = READING_U16; chip->write = WRITING_U16; } else { if (pl022->vendor->max_bpw >= 32) { dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n"); chip->n_bytes = 4; chip->read = READING_U32; chip->write = WRITING_U32; } else { dev_err(&spi->dev, "illegal data size for this controller!\n"); dev_err(&spi->dev, "a standard pl022 can only handle " "1 <= n <= 16 bit words\n"); goto err_config_params; } } /* Now Initialize all register settings required for this chip */ chip->cr0 = 0; chip->cr1 = 0; chip->dmacr = 0; chip->cpsr = 0; if ((chip_info->com_mode == DMA_TRANSFER) && ((pl022->master_info)->enable_dma)) { chip->enable_dma = 1; dev_dbg(&spi->dev, "DMA mode set in controller state\n"); status = process_dma_info(chip_info, chip); if (status < 0) goto err_config_params; SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, SSP_DMACR_MASK_RXDMAE, 0); SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED, SSP_DMACR_MASK_TXDMAE, 1); } else { chip->enable_dma = 0; dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n"); SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0); SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1); } chip->cpsr = chip_info->clk_freq.cpsdvsr; /* Special setup for the ST micro extended control registers */ if (pl022->vendor->extended_cr) { if (pl022->vendor->pl023) { /* These bits are only in the PL023 */ SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay, SSP_CR1_MASK_FBCLKDEL_ST, 13); } else { /* These bits are in the PL022 but not PL023 */ SSP_WRITE_BITS(chip->cr0, chip_info->duplex, SSP_CR0_MASK_HALFDUP_ST, 5); SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len, SSP_CR0_MASK_CSS_ST, 16); SSP_WRITE_BITS(chip->cr0, chip_info->iface, SSP_CR0_MASK_FRF_ST, 21); SSP_WRITE_BITS(chip->cr1, chip_info->wait_state, SSP_CR1_MASK_MWAIT_ST, 6); } SSP_WRITE_BITS(chip->cr0, chip_info->data_size, SSP_CR0_MASK_DSS_ST, 0); SSP_WRITE_BITS(chip->cr1, chip_info->endian_rx, SSP_CR1_MASK_RENDN_ST, 4); SSP_WRITE_BITS(chip->cr1, chip_info->endian_tx, SSP_CR1_MASK_TENDN_ST, 5); SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig, SSP_CR1_MASK_RXIFLSEL_ST, 7); SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig, SSP_CR1_MASK_TXIFLSEL_ST, 10); } else { SSP_WRITE_BITS(chip->cr0, chip_info->data_size, SSP_CR0_MASK_DSS, 0); SSP_WRITE_BITS(chip->cr0, chip_info->iface, SSP_CR0_MASK_FRF, 4); } /* Stuff that is common for all versions */ SSP_WRITE_BITS(chip->cr0, chip_info->clk_pol, SSP_CR0_MASK_SPO, 6); SSP_WRITE_BITS(chip->cr0, chip_info->clk_phase, SSP_CR0_MASK_SPH, 7); SSP_WRITE_BITS(chip->cr0, chip_info->clk_freq.scr, SSP_CR0_MASK_SCR, 8); /* Loopback is available on all versions except PL023 */ if (!pl022->vendor->pl023) SSP_WRITE_BITS(chip->cr1, chip_info->lbm, SSP_CR1_MASK_LBM, 0); SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1); SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2); SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD, 3); /* Save controller_state */ spi_set_ctldata(spi, chip); return status; err_config_params: err_first_setup: kfree(chip); return status; } /** * pl022_cleanup - cleanup function registered to SPI master framework * @spi: spi device which is requesting cleanup * * This function is registered to the SPI framework for this SPI master * controller. It will free the runtime state of chip. */ static void pl022_cleanup(struct spi_device *spi) { struct chip_data *chip = spi_get_ctldata(spi); spi_set_ctldata(spi, NULL); kfree(chip); } static int __init pl022_probe(struct amba_device *adev, struct amba_id *id) { struct device *dev = &adev->dev; struct pl022_ssp_controller *platform_info = adev->dev.platform_data; struct spi_master *master; struct pl022 *pl022 = NULL; /*Data for this driver */ int status = 0; dev_info(&adev->dev, "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid); if (platform_info == NULL) { dev_err(&adev->dev, "probe - no platform data supplied\n"); status = -ENODEV; goto err_no_pdata; } /* Allocate master with space for data */ master = spi_alloc_master(dev, sizeof(struct pl022)); if (master == NULL) { dev_err(&adev->dev, "probe - cannot alloc SPI master\n"); status = -ENOMEM; goto err_no_master; } pl022 = spi_master_get_devdata(master); pl022->master = master; pl022->master_info = platform_info; pl022->adev = adev; pl022->vendor = id->data; /* * Bus Number Which has been Assigned to this SSP controller * on this board */ master->bus_num = platform_info->bus_id; master->num_chipselect = platform_info->num_chipselect; master->cleanup = pl022_cleanup; master->setup = pl022_setup; master->transfer = pl022_transfer; dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num); status = amba_request_regions(adev, NULL); if (status) goto err_no_ioregion; pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res)); if (pl022->virtbase == NULL) { status = -ENOMEM; goto err_no_ioremap; } printk(KERN_INFO "pl022: mapped registers from 0x%08x to %p\n", adev->res.start, pl022->virtbase); pl022->clk = clk_get(&adev->dev, NULL); if (IS_ERR(pl022->clk)) { status = PTR_ERR(pl022->clk); dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n"); goto err_no_clk; } /* Disable SSP */ clk_enable(pl022->clk); writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase)); load_ssp_default_config(pl022); clk_disable(pl022->clk); status = request_irq(adev->irq[0], pl022_interrupt_handler, 0, "pl022", pl022); if (status < 0) { dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status); goto err_no_irq; } /* Initialize and start queue */ status = init_queue(pl022); if (status != 0) { dev_err(&adev->dev, "probe - problem initializing queue\n"); goto err_init_queue; } status = start_queue(pl022); if (status != 0) { dev_err(&adev->dev, "probe - problem starting queue\n"); goto err_start_queue; } /* Register with the SPI framework */ amba_set_drvdata(adev, pl022); status = spi_register_master(master); if (status != 0) { dev_err(&adev->dev, "probe - problem registering spi master\n"); goto err_spi_register; } dev_dbg(dev, "probe succeded\n"); return 0; err_spi_register: err_start_queue: err_init_queue: destroy_queue(pl022); free_irq(adev->irq[0], pl022); err_no_irq: clk_put(pl022->clk); err_no_clk: iounmap(pl022->virtbase); err_no_ioremap: amba_release_regions(adev); err_no_ioregion: spi_master_put(master); err_no_master: err_no_pdata: return status; } static int __exit pl022_remove(struct amba_device *adev) { struct pl022 *pl022 = amba_get_drvdata(adev); int status = 0; if (!pl022) return 0; /* Remove the queue */ status = destroy_queue(pl022); if (status != 0) { dev_err(&adev->dev, "queue remove failed (%d)\n", status); return status; } load_ssp_default_config(pl022); free_irq(adev->irq[0], pl022); clk_disable(pl022->clk); clk_put(pl022->clk); iounmap(pl022->virtbase); amba_release_regions(adev); tasklet_disable(&pl022->pump_transfers); spi_unregister_master(pl022->master); spi_master_put(pl022->master); amba_set_drvdata(adev, NULL); dev_dbg(&adev->dev, "remove succeded\n"); return 0; } #ifdef CONFIG_PM static int pl022_suspend(struct amba_device *adev, pm_message_t state) { struct pl022 *pl022 = amba_get_drvdata(adev); int status = 0; status = stop_queue(pl022); if (status) { dev_warn(&adev->dev, "suspend cannot stop queue\n"); return status; } clk_enable(pl022->clk); load_ssp_default_config(pl022); clk_disable(pl022->clk); dev_dbg(&adev->dev, "suspended\n"); return 0; } static int pl022_resume(struct amba_device *adev) { struct pl022 *pl022 = amba_get_drvdata(adev); int status = 0; /* Start the queue running */ status = start_queue(pl022); if (status) dev_err(&adev->dev, "problem starting queue (%d)\n", status); else dev_dbg(&adev->dev, "resumed\n"); return status; } #else #define pl022_suspend NULL #define pl022_resume NULL #endif /* CONFIG_PM */ static struct vendor_data vendor_arm = { .fifodepth = 8, .max_bpw = 16, .unidir = false, .extended_cr = false, .pl023 = false, }; static struct vendor_data vendor_st = { .fifodepth = 32, .max_bpw = 32, .unidir = false, .extended_cr = true, .pl023 = false, }; static struct vendor_data vendor_st_pl023 = { .fifodepth = 32, .max_bpw = 32, .unidir = false, .extended_cr = true, .pl023 = true, }; static struct amba_id pl022_ids[] = { { /* * ARM PL022 variant, this has a 16bit wide * and 8 locations deep TX/RX FIFO */ .id = 0x00041022, .mask = 0x000fffff, .data = &vendor_arm, }, { /* * ST Micro derivative, this has 32bit wide * and 32 locations deep TX/RX FIFO */ .id = 0x01080022, .mask = 0xffffffff, .data = &vendor_st, }, { /* * ST-Ericsson derivative "PL023" (this is not * an official ARM number), this is a PL022 SSP block * stripped to SPI mode only, it has 32bit wide * and 32 locations deep TX/RX FIFO but no extended * CR0/CR1 register */ .id = 0x00080023, .mask = 0xffffffff, .data = &vendor_st_pl023, }, { 0, 0 }, }; static struct amba_driver pl022_driver = { .drv = { .name = "ssp-pl022", }, .id_table = pl022_ids, .probe = pl022_probe, .remove = __exit_p(pl022_remove), .suspend = pl022_suspend, .resume = pl022_resume, }; static int __init pl022_init(void) { return amba_driver_register(&pl022_driver); } module_init(pl022_init); static void __exit pl022_exit(void) { amba_driver_unregister(&pl022_driver); } module_exit(pl022_exit); MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>"); MODULE_DESCRIPTION("PL022 SSP Controller Driver"); MODULE_LICENSE("GPL");