diff options
Diffstat (limited to 'drivers/spi/pxa2xx_spi.c')
| -rw-r--r-- | drivers/spi/pxa2xx_spi.c | 1399 |
1 files changed, 1399 insertions, 0 deletions
diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c new file mode 100644 index 00000000000..913e1aff023 --- /dev/null +++ b/drivers/spi/pxa2xx_spi.c @@ -0,0 +1,1399 @@ +/* + * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#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/platform_device.h> +#include <linux/dma-mapping.h> +#include <linux/spi/spi.h> +#include <linux/workqueue.h> +#include <linux/errno.h> +#include <linux/delay.h> + +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/hardware.h> +#include <asm/delay.h> +#include <asm/dma.h> + +#include <asm/arch/hardware.h> +#include <asm/arch/pxa-regs.h> +#include <asm/arch/pxa2xx_spi.h> + +MODULE_AUTHOR("Stephen Street"); +MODULE_DESCRIPTION("PXA2xx SSP SPI Contoller"); +MODULE_LICENSE("GPL"); + +#define MAX_BUSES 3 + +#define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR) +#define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) +#define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0) + +#define DEFINE_SSP_REG(reg, off) \ +static inline u32 read_##reg(void *p) { return __raw_readl(p + (off)); } \ +static inline void write_##reg(u32 v, void *p) { __raw_writel(v, p + (off)); } + +DEFINE_SSP_REG(SSCR0, 0x00) +DEFINE_SSP_REG(SSCR1, 0x04) +DEFINE_SSP_REG(SSSR, 0x08) +DEFINE_SSP_REG(SSITR, 0x0c) +DEFINE_SSP_REG(SSDR, 0x10) +DEFINE_SSP_REG(SSTO, 0x28) +DEFINE_SSP_REG(SSPSP, 0x2c) + +#define START_STATE ((void*)0) +#define RUNNING_STATE ((void*)1) +#define DONE_STATE ((void*)2) +#define ERROR_STATE ((void*)-1) + +#define QUEUE_RUNNING 0 +#define QUEUE_STOPPED 1 + +struct driver_data { + /* Driver model hookup */ + struct platform_device *pdev; + + /* SPI framework hookup */ + enum pxa_ssp_type ssp_type; + struct spi_master *master; + + /* PXA hookup */ + struct pxa2xx_spi_master *master_info; + + /* DMA setup stuff */ + int rx_channel; + int tx_channel; + u32 *null_dma_buf; + + /* SSP register addresses */ + void *ioaddr; + u32 ssdr_physical; + + /* SSP masks*/ + u32 dma_cr1; + u32 int_cr1; + u32 clear_sr; + u32 mask_sr; + + /* Driver message queue */ + struct workqueue_struct *workqueue; + struct work_struct pump_messages; + spinlock_t lock; + struct list_head queue; + int busy; + int run; + + /* Message Transfer pump */ + struct tasklet_struct pump_transfers; + + /* Current message transfer state info */ + struct spi_message* cur_msg; + struct spi_transfer* cur_transfer; + struct chip_data *cur_chip; + size_t len; + void *tx; + void *tx_end; + void *rx; + void *rx_end; + int dma_mapped; + dma_addr_t rx_dma; + dma_addr_t tx_dma; + size_t rx_map_len; + size_t tx_map_len; + int cs_change; + void (*write)(struct driver_data *drv_data); + void (*read)(struct driver_data *drv_data); + irqreturn_t (*transfer_handler)(struct driver_data *drv_data); + void (*cs_control)(u32 command); +}; + +struct chip_data { + u32 cr0; + u32 cr1; + u32 to; + u32 psp; + u32 timeout; + u8 n_bytes; + u32 dma_width; + u32 dma_burst_size; + u32 threshold; + u32 dma_threshold; + u8 enable_dma; + void (*write)(struct driver_data *drv_data); + void (*read)(struct driver_data *drv_data); + void (*cs_control)(u32 command); +}; + +static void pump_messages(void *data); + +static int flush(struct driver_data *drv_data) +{ + unsigned long limit = loops_per_jiffy << 1; + + void *reg = drv_data->ioaddr; + + do { + while (read_SSSR(reg) & SSSR_RNE) { + read_SSDR(reg); + } + } while ((read_SSSR(reg) & SSSR_BSY) && limit--); + write_SSSR(SSSR_ROR, reg); + + return limit; +} + +static void restore_state(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + + /* Clear status and disable clock */ + write_SSSR(drv_data->clear_sr, reg); + write_SSCR0(drv_data->cur_chip->cr0 & ~SSCR0_SSE, reg); + + /* Load the registers */ + write_SSCR1(drv_data->cur_chip->cr1, reg); + write_SSCR0(drv_data->cur_chip->cr0, reg); + if (drv_data->ssp_type != PXA25x_SSP) { + write_SSTO(0, reg); + write_SSPSP(drv_data->cur_chip->psp, reg); + } +} + +static void null_cs_control(u32 command) +{ +} + +static void null_writer(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + u8 n_bytes = drv_data->cur_chip->n_bytes; + + while ((read_SSSR(reg) & SSSR_TNF) + && (drv_data->tx < drv_data->tx_end)) { + write_SSDR(0, reg); + drv_data->tx += n_bytes; + } +} + +static void null_reader(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + u8 n_bytes = drv_data->cur_chip->n_bytes; + + while ((read_SSSR(reg) & SSSR_RNE) + && (drv_data->rx < drv_data->rx_end)) { + read_SSDR(reg); + drv_data->rx += n_bytes; + } +} + +static void u8_writer(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + + while ((read_SSSR(reg) & SSSR_TNF) + && (drv_data->tx < drv_data->tx_end)) { + write_SSDR(*(u8 *)(drv_data->tx), reg); + ++drv_data->tx; + } +} + +static void u8_reader(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + + while ((read_SSSR(reg) & SSSR_RNE) + && (drv_data->rx < drv_data->rx_end)) { + *(u8 *)(drv_data->rx) = read_SSDR(reg); + ++drv_data->rx; + } +} + +static void u16_writer(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + + while ((read_SSSR(reg) & SSSR_TNF) + && (drv_data->tx < drv_data->tx_end)) { + write_SSDR(*(u16 *)(drv_data->tx), reg); + drv_data->tx += 2; + } +} + +static void u16_reader(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + + while ((read_SSSR(reg) & SSSR_RNE) + && (drv_data->rx < drv_data->rx_end)) { + *(u16 *)(drv_data->rx) = read_SSDR(reg); + drv_data->rx += 2; + } +} +static void u32_writer(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + + while ((read_SSSR(reg) & SSSR_TNF) + && (drv_data->tx < drv_data->tx_end)) { + write_SSDR(*(u16 *)(drv_data->tx), reg); + drv_data->tx += 4; + } +} + +static void u32_reader(struct driver_data *drv_data) +{ + void *reg = drv_data->ioaddr; + + while ((read_SSSR(reg) & SSSR_RNE) + && (drv_data->rx < drv_data->rx_end)) { + *(u32 *)(drv_data->rx) = read_SSDR(reg); + drv_data->rx += 4; + } +} + +static void *next_transfer(struct driver_data *drv_data) +{ + struct spi_message *msg = drv_data->cur_msg; + struct spi_transfer *trans = drv_data->cur_transfer; + + /* Move to next transfer */ + if (trans->transfer_list.next != &msg->transfers) { + drv_data->cur_transfer = + list_entry(trans->transfer_list.next, + struct spi_transfer, + transfer_list); + return RUNNING_STATE; + } else + return DONE_STATE; +} + +static int map_dma_buffers(struct driver_data *drv_data) +{ + struct spi_message *msg = drv_data->cur_msg; + struct device *dev = &msg->spi->dev; + + if (!drv_data->cur_chip->enable_dma) + return 0; + + if (msg->is_dma_mapped) + return drv_data->rx_dma && drv_data->tx_dma; + + if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx)) + return 0; + + /* Modify setup if rx buffer is null */ + if (drv_data->rx == NULL) { + *drv_data->null_dma_buf = 0; + drv_data->rx = drv_data->null_dma_buf; + drv_data->rx_map_len = 4; + } else + drv_data->rx_map_len = drv_data->len; + + + /* Modify setup if tx buffer is null */ + if (drv_data->tx == NULL) { + *drv_data->null_dma_buf = 0; + drv_data->tx = drv_data->null_dma_buf; + drv_data->tx_map_len = 4; + } else + drv_data->tx_map_len = drv_data->len; + + /* Stream map the rx buffer */ + drv_data->rx_dma = dma_map_single(dev, drv_data->rx, + drv_data->rx_map_len, + DMA_FROM_DEVICE); + if (dma_mapping_error(drv_data->rx_dma)) + return 0; + + /* Stream map the tx buffer */ + drv_data->tx_dma = dma_map_single(dev, drv_data->tx, + drv_data->tx_map_len, + DMA_TO_DEVICE); + + if (dma_mapping_error(drv_data->tx_dma)) { + dma_unmap_single(dev, drv_data->rx_dma, + drv_data->rx_map_len, DMA_FROM_DEVICE); + return 0; + } + + return 1; +} + +static void unmap_dma_buffers(struct driver_data *drv_data) +{ + struct device *dev; + + if (!drv_data->dma_mapped) + return; + + if (!drv_data->cur_msg->is_dma_mapped) { + dev = &drv_data->cur_msg->spi->dev; + dma_unmap_single(dev, drv_data->rx_dma, + drv_data->rx_map_len, DMA_FROM_DEVICE); + dma_unmap_single(dev, drv_data->tx_dma, + drv_data->tx_map_len, DMA_TO_DEVICE); + } + + drv_data->dma_mapped = 0; +} + +/* caller already set message->status; dma and pio irqs are blocked */ +static void giveback(struct spi_message *message, struct driver_data *drv_data) +{ + struct spi_transfer* last_transfer; + + last_transfer = list_entry(message->transfers.prev, + struct spi_transfer, + transfer_list); + + if (!last_transfer->cs_change) + drv_data->cs_control(PXA2XX_CS_DEASSERT); + + message->state = NULL; + if (message->complete) + message->complete(message->context); + + drv_data->cur_msg = NULL; + drv_data->cur_transfer = NULL; + drv_data->cur_chip = NULL; + queue_work(drv_data->workqueue, &drv_data->pump_messages); +} + +static int wait_ssp_rx_stall(void *ioaddr) +{ + unsigned long limit = loops_per_jiffy << 1; + + while ((read_SSSR(ioaddr) & SSSR_BSY) && limit--) + cpu_relax(); + + return limit; +} + +static int wait_dma_channel_stop(int channel) +{ + unsigned long limit = loops_per_jiffy << 1; + + while (!(DCSR(channel) & DCSR_STOPSTATE) && limit--) + cpu_relax(); + + return limit; +} + +static void dma_handler(int channel, void *data, struct pt_regs *regs) +{ + struct driver_data *drv_data = data; + struct spi_message *msg = drv_data->cur_msg; + void *reg = drv_data->ioaddr; + u32 irq_status = DCSR(channel) & DMA_INT_MASK; + u32 trailing_sssr = 0; + + if (irq_status & DCSR_BUSERR) { + + /* Disable interrupts, clear status and reset DMA */ + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(0, reg); + write_SSSR(drv_data->clear_sr, reg); + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + + if (flush(drv_data) == 0) + dev_err(&drv_data->pdev->dev, + "dma_handler: flush fail\n"); + + unmap_dma_buffers(drv_data); + + if (channel == drv_data->tx_channel) + dev_err(&drv_data->pdev->dev, + "dma_handler: bad bus address on " + "tx channel %d, source %x target = %x\n", + channel, DSADR(channel), DTADR(channel)); + else + dev_err(&drv_data->pdev->dev, + "dma_handler: bad bus address on " + "rx channel %d, source %x target = %x\n", + channel, DSADR(channel), DTADR(channel)); + + msg->state = ERROR_STATE; + tasklet_schedule(&drv_data->pump_transfers); + } + + /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */ + if ((drv_data->ssp_type == PXA25x_SSP) + && (channel == drv_data->tx_channel) + && (irq_status & DCSR_ENDINTR)) { + + /* Wait for rx to stall */ + if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) + dev_err(&drv_data->pdev->dev, + "dma_handler: ssp rx stall failed\n"); + + /* Clear and disable interrupts on SSP and DMA channels*/ + write_SSSR(drv_data->clear_sr, reg); + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + if (wait_dma_channel_stop(drv_data->rx_channel) == 0) + dev_err(&drv_data->pdev->dev, + "dma_handler: dma rx channel stop failed\n"); + + unmap_dma_buffers(drv_data); + + /* Read trailing bytes */ + /* Calculate number of trailing bytes, read them */ + trailing_sssr = read_SSSR(reg); + if ((trailing_sssr & 0xf008) != 0xf000) { + drv_data->rx = drv_data->rx_end - + (((trailing_sssr >> 12) & 0x0f) + 1); + drv_data->read(drv_data); + } + msg->actual_length += drv_data->len; + + /* Release chip select if requested, transfer delays are + * handled in pump_transfers */ + if (drv_data->cs_change) + drv_data->cs_control(PXA2XX_CS_DEASSERT); + + /* Move to next transfer */ + msg->state = next_transfer(drv_data); + + /* Schedule transfer tasklet */ + tasklet_schedule(&drv_data->pump_transfers); + } +} + +static irqreturn_t dma_transfer(struct driver_data *drv_data) +{ + u32 irq_status; + u32 trailing_sssr = 0; + struct spi_message *msg = drv_data->cur_msg; + void *reg = drv_data->ioaddr; + + irq_status = read_SSSR(reg) & drv_data->mask_sr; + if (irq_status & SSSR_ROR) { + /* Clear and disable interrupts on SSP and DMA channels*/ + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(0, reg); + write_SSSR(drv_data->clear_sr, reg); + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + unmap_dma_buffers(drv_data); + + if (flush(drv_data) == 0) + dev_err(&drv_data->pdev->dev, + "dma_transfer: flush fail\n"); + + dev_warn(&drv_data->pdev->dev, "dma_transfer: fifo overun\n"); + + drv_data->cur_msg->state = ERROR_STATE; + tasklet_schedule(&drv_data->pump_transfers); + + return IRQ_HANDLED; + } + + /* Check for false positive timeout */ + if ((irq_status & SSSR_TINT) && DCSR(drv_data->tx_channel) & DCSR_RUN) { + write_SSSR(SSSR_TINT, reg); + return IRQ_HANDLED; + } + + if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) { + + /* Clear and disable interrupts on SSP and DMA channels*/ + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(0, reg); + write_SSSR(drv_data->clear_sr, reg); + write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + + if (wait_dma_channel_stop(drv_data->rx_channel) == 0) + dev_err(&drv_data->pdev->dev, + "dma_transfer: dma rx channel stop failed\n"); + + if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) + dev_err(&drv_data->pdev->dev, + "dma_transfer: ssp rx stall failed\n"); + + unmap_dma_buffers(drv_data); + + /* Calculate number of trailing bytes, read them */ + trailing_sssr = read_SSSR(reg); + if ((trailing_sssr & 0xf008) != 0xf000) { + drv_data->rx = drv_data->rx_end - + (((trailing_sssr >> 12) & 0x0f) + 1); + drv_data->read(drv_data); + } + msg->actual_length += drv_data->len; + + /* Release chip select if requested, transfer delays are + * handled in pump_transfers */ + if (drv_data->cs_change) + drv_data->cs_control(PXA2XX_CS_DEASSERT); + + /* Move to next transfer */ + msg->state = next_transfer(drv_data); + + /* Schedule transfer tasklet */ + tasklet_schedule(&drv_data->pump_transfers); + + return IRQ_HANDLED; + } + + /* Opps problem detected */ + return IRQ_NONE; +} + +static irqreturn_t interrupt_transfer(struct driver_data *drv_data) +{ + u32 irq_status; + struct spi_message *msg = drv_data->cur_msg; + void *reg = drv_data->ioaddr; + irqreturn_t handled = IRQ_NONE; + unsigned long limit = loops_per_jiffy << 1; + + while ((irq_status = (read_SSSR(reg) & drv_data->mask_sr))) { + + if (irq_status & SSSR_ROR) { + + /* Clear and disable interrupts */ + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(0, reg); + write_SSSR(drv_data->clear_sr, reg); + write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg); + + if (flush(drv_data) == 0) + dev_err(&drv_data->pdev->dev, + "interrupt_transfer: flush fail\n"); + + dev_warn(&drv_data->pdev->dev, + "interrupt_transfer: fifo overun\n"); + + msg->state = ERROR_STATE; + tasklet_schedule(&drv_data->pump_transfers); + + return IRQ_HANDLED; + } + + /* Look for false positive timeout */ + if ((irq_status & SSSR_TINT) + && (drv_data->rx < drv_data->rx_end)) + write_SSSR(SSSR_TINT, reg); + + /* Pump data */ + drv_data->read(drv_data); + drv_data->write(drv_data); + + if (drv_data->tx == drv_data->tx_end) { + /* Disable tx interrupt */ + write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg); + + /* PXA25x_SSP has no timeout, read trailing bytes */ + if (drv_data->ssp_type == PXA25x_SSP) { + while ((read_SSSR(reg) & SSSR_BSY) && limit--) + drv_data->read(drv_data); + + if (limit == 0) + dev_err(&drv_data->pdev->dev, + "interrupt_transfer: " + "trailing byte read failed\n"); + } + } + + if ((irq_status & SSSR_TINT) + || (drv_data->rx == drv_data->rx_end)) { + + /* Clear timeout */ + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(0, reg); + write_SSSR(drv_data->clear_sr, reg); + write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg); + + /* Update total byte transfered */ + msg->actual_length += drv_data->len; + + /* Release chip select if requested, transfer delays are + * handled in pump_transfers */ + if (drv_data->cs_change) + drv_data->cs_control(PXA2XX_CS_DEASSERT); + + /* Move to next transfer */ + msg->state = next_transfer(drv_data); + + /* Schedule transfer tasklet */ + tasklet_schedule(&drv_data->pump_transfers); + + return IRQ_HANDLED; + } + + /* We did something */ + handled = IRQ_HANDLED; + } + + return handled; +} + +static irqreturn_t ssp_int(int irq, void *dev_id, struct pt_regs *regs) +{ + struct driver_data *drv_data = (struct driver_data *)dev_id; + + if (!drv_data->cur_msg) { + dev_err(&drv_data->pdev->dev, "bad message state " + "in interrupt handler\n"); + /* Never fail */ + return IRQ_HANDLED; + } + + return drv_data->transfer_handler(drv_data); +} + +static void pump_transfers(unsigned long data) +{ + struct driver_data *drv_data = (struct driver_data *)data; + struct spi_message *message = NULL; + struct spi_transfer *transfer = NULL; + struct spi_transfer *previous = NULL; + struct chip_data *chip = NULL; + void *reg = drv_data->ioaddr; + + /* Get current state information */ + message = drv_data->cur_msg; + transfer = drv_data->cur_transfer; + chip = drv_data->cur_chip; + + /* Handle for abort */ + if (message->state == ERROR_STATE) { + message->status = -EIO; + giveback(message, drv_data); + return; + } + + /* Handle end of message */ + if (message->state == DONE_STATE) { + message->status = 0; + giveback(message, drv_data); + return; + } + + /* Delay if requested at end of transfer*/ + if (message->state == RUNNING_STATE) { + previous = list_entry(transfer->transfer_list.prev, + struct spi_transfer, + transfer_list); + if (previous->delay_usecs) + udelay(previous->delay_usecs); + } + + /* Setup the transfer state based on the type of transfer */ + if (flush(drv_data) == 0) { + dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n"); + message->status = -EIO; + giveback(message, drv_data); + return; + } + drv_data->cs_control = chip->cs_control; + drv_data->tx = (void *)transfer->tx_buf; + drv_data->tx_end = drv_data->tx + transfer->len; + drv_data->rx = transfer->rx_buf; + drv_data->rx_end = drv_data->rx + transfer->len; + drv_data->rx_dma = transfer->rx_dma; + drv_data->tx_dma = transfer->tx_dma; + drv_data->len = transfer->len; + drv_data->write = drv_data->tx ? chip->write : null_writer; + drv_data->read = drv_data->rx ? chip->read : null_reader; + drv_data->cs_change = transfer->cs_change; + message->state = RUNNING_STATE; + + /* Try to map dma buffer and do a dma transfer if successful */ + if ((drv_data->dma_mapped = map_dma_buffers(drv_data))) { + + /* Ensure we have the correct interrupt handler */ + drv_data->transfer_handler = dma_transfer; + + /* Setup rx DMA Channel */ + DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; + DSADR(drv_data->rx_channel) = drv_data->ssdr_physical; + DTADR(drv_data->rx_channel) = drv_data->rx_dma; + if (drv_data->rx == drv_data->null_dma_buf) + /* No target address increment */ + DCMD(drv_data->rx_channel) = DCMD_FLOWSRC + | chip->dma_width + | chip->dma_burst_size + | drv_data->len; + else + DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR + | DCMD_FLOWSRC + | chip->dma_width + | chip->dma_burst_size + | drv_data->len; + + /* Setup tx DMA Channel */ + DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; + DSADR(drv_data->tx_channel) = drv_data->tx_dma; + DTADR(drv_data->tx_channel) = drv_data->ssdr_physical; + if (drv_data->tx == drv_data->null_dma_buf) + /* No source address increment */ + DCMD(drv_data->tx_channel) = DCMD_FLOWTRG + | chip->dma_width + | chip->dma_burst_size + | drv_data->len; + else + DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR + | DCMD_FLOWTRG + | chip->dma_width + | chip->dma_burst_size + | drv_data->len; + + /* Enable dma end irqs on SSP to detect end of transfer */ + if (drv_data->ssp_type == PXA25x_SSP) + DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN; + + /* Fix me, need to handle cs polarity */ + drv_data->cs_control(PXA2XX_CS_ASSERT); + + /* Go baby, go */ + write_SSSR(drv_data->clear_sr, reg); + DCSR(drv_data->rx_channel) |= DCSR_RUN; + DCSR(drv_data->tx_channel) |= DCSR_RUN; + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(chip->timeout, reg); + write_SSCR1(chip->cr1 + | chip->dma_threshold + | drv_data->dma_cr1, + reg); + } else { + /* Ensure we have the correct interrupt handler */ + drv_data->transfer_handler = interrupt_transfer; + + /* Fix me, need to handle cs polarity */ + drv_data->cs_control(PXA2XX_CS_ASSERT); + + /* Go baby, go */ + write_SSSR(drv_data->clear_sr, reg); + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(chip->timeout, reg); + write_SSCR1(chip->cr1 + | chip->threshold + | drv_data->int_cr1, + reg); + } +} + +static void pump_messages(void *data) +{ + struct driver_data *drv_data = data; + unsigned long flags; + + /* Lock queue and check for queue work */ + spin_lock_irqsave(&drv_data->lock, flags); + if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) { + drv_data->busy = 0; + spin_unlock_irqrestore(&drv_data->lock, flags); + return; + } + + /* Make sure we are not already running a message */ + if (drv_data->cur_msg) { + spin_unlock_irqrestore(&drv_data->lock, flags); + return; + } + + /* Extract head of queue */ + drv_data->cur_msg = list_entry(drv_data->queue.next, + struct spi_message, queue); + list_del_init(&drv_data->cur_msg->queue); + drv_data->busy = 1; + spin_unlock_irqrestore(&drv_data->lock, flags); + + /* Initial message state*/ + drv_data->cur_msg->state = START_STATE; + drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next, + struct spi_transfer, + transfer_list); + + /* Setup the SSP using the per chip configuration */ + drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi); + restore_state(drv_data); + + /* Mark as busy and launch transfers */ + tasklet_schedule(&drv_data->pump_transfers); +} + +static int transfer(struct spi_device *spi, struct spi_message *msg) +{ + struct driver_data *drv_data = spi_master_get_devdata(spi->master); + unsigned long flags; + + spin_lock_irqsave(&drv_data->lock, flags); + + if (drv_data->run == QUEUE_STOPPED) { + spin_unlock_irqrestore(&drv_data->lock, flags); + return -ESHUTDOWN; + } + + msg->actual_length = 0; + msg->status = -EINPROGRESS; + msg->state = START_STATE; + + list_add_tail(&msg->queue, &drv_data->queue); + + if (drv_data->run == QUEUE_RUNNING && !drv_data->busy) + queue_work(drv_data->workqueue, &drv_data->pump_messages); + + spin_unlock_irqrestore(&drv_data->lock, flags); + + return 0; +} + +static int setup(struct spi_device *spi) +{ + struct pxa2xx_spi_chip *chip_info = NULL; + struct chip_data *chip; + struct driver_data *drv_data = spi_master_get_devdata(spi->master); + unsigned int clk_div; + + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + if (drv_data->ssp_type != PXA25x_SSP + && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) + return -EINVAL; + else if (spi->bits_per_word < 4 || spi->bits_per_word > 16) + return -EINVAL; + + /* Only alloc (or use chip_info) on first setup */ + chip = spi_get_ctldata(spi); + if (chip == NULL) { + chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->cs_control = null_cs_control; + chip->enable_dma = 0; + chip->timeout = 5; + chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1); + chip->dma_burst_size = drv_data->master_info->enable_dma ? + DCMD_BURST8 : 0; + + chip_info = spi->controller_data; + } + + /* chip_info isn't always needed */ + if (chip_info) { + if (chip_info->cs_control) + chip->cs_control = chip_info->cs_control; + + chip->timeout = (chip_info->timeout_microsecs * 10000) / 2712; + + chip->threshold = SSCR1_RxTresh(chip_info->rx_threshold) + | SSCR1_TxTresh(chip_info->tx_threshold); + + chip->enable_dma = chip_info->dma_burst_size != 0 + && drv_data->master_info->enable_dma; + chip->dma_threshold = 0; + + if (chip->enable_dma) { + if (chip_info->dma_burst_size <= 8) { + chip->dma_threshold = SSCR1_RxTresh(8) + | SSCR1_TxTresh(8); + chip->dma_burst_size = DCMD_BURST8; + } else if (chip_info->dma_burst_size <= 16) { + chip->dma_threshold = SSCR1_RxTresh(16) + | SSCR1_TxTresh(16); + chip->dma_burst_size = DCMD_BURST16; + } else { + chip->dma_threshold = SSCR1_RxTresh(32) + | SSCR1_TxTresh(32); + chip->dma_burst_size = DCMD_BURST32; + } + } + + + if (chip_info->enable_loopback) + chip->cr1 = SSCR1_LBM; + } + + if (drv_data->ioaddr == SSP1_VIRT) + clk_div = SSP1_SerClkDiv(spi->max_speed_hz); + else if (drv_data->ioaddr == SSP2_VIRT) + clk_div = SSP2_SerClkDiv(spi->max_speed_hz); + else if (drv_data->ioaddr == SSP3_VIRT) + clk_div = SSP3_SerClkDiv(spi->max_speed_hz); + else + return -ENODEV; + + chip->cr0 = clk_div + | SSCR0_Motorola + | SSCR0_DataSize(spi->bits_per_word & 0x0f) + | SSCR0_SSE + | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0); + chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) << 4) + | (((spi->mode & SPI_CPOL) != 0) << 3); + + /* NOTE: PXA25x_SSP _could_ use external clocking ... */ + if (drv_data->ssp_type != PXA25x_SSP) + dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n", + spi->bits_per_word, + (CLOCK_SPEED_HZ) + / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)), + spi->mode & 0x3); + else + dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n", + spi->bits_per_word, + (CLOCK_SPEED_HZ/2) + / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)), + spi->mode & 0x3); + + if (spi->bits_per_word <= 8) { + chip->n_bytes = 1; + chip->dma_width = DCMD_WIDTH1; + chip->read = u8_reader; + chip->write = u8_writer; + } else if (spi->bits_per_word <= 16) { + chip->n_bytes = 2; + chip->dma_width = DCMD_WIDTH2; + chip->read = u16_reader; + chip->write = u16_writer; + } else if (spi->bits_per_word <= 32) { + chip->cr0 |= SSCR0_EDSS; + chip->n_bytes = 4; + chip->dma_width = DCMD_WIDTH4; + chip->read = u32_reader; + chip->write = u32_writer; + } else { + dev_err(&spi->dev, "invalid wordsize\n"); + kfree(chip); + return -ENODEV; + } + + spi_set_ctldata(spi, chip); + + return 0; +} + +static void cleanup(const struct spi_device *spi) +{ + struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi); + + kfree(chip); +} + +static int init_queue(struct driver_data *drv_data) +{ + INIT_LIST_HEAD(&drv_data->queue); + spin_lock_init(&drv_data->lock); + + drv_data->run = QUEUE_STOPPED; + drv_data->busy = 0; + + tasklet_init(&drv_data->pump_transfers, + pump_transfers, (unsigned long)drv_data); + + INIT_WORK(&drv_data->pump_messages, pump_messages, drv_data); + drv_data->workqueue = create_singlethread_workqueue( + drv_data->master->cdev.dev->bus_id); + if (drv_data->workqueue == NULL) + return -EBUSY; + + return 0; +} + +static int start_queue(struct driver_data *drv_data) +{ + unsigned long flags; + + spin_lock_irqsave(&drv_data->lock, flags); + + if (drv_data->run == QUEUE_RUNNING || drv_data->busy) { + spin_unlock_irqrestore(&drv_data->lock, flags); + return -EBUSY; + } + + drv_data->run = QUEUE_RUNNING; + drv_data->cur_msg = NULL; + drv_data->cur_transfer = NULL; + drv_data->cur_chip = NULL; + spin_unlock_irqrestore(&drv_data->lock, flags); + + queue_work(drv_data->workqueue, &drv_data->pump_messages); + + return 0; +} + +static int stop_queue(struct driver_data *drv_data) +{ + unsigned long flags; + unsigned limit = 500; + int status = 0; + + spin_lock_irqsave(&drv_data->lock, flags); + + /* This is a bit lame, but is optimized for the common execution path. + * A wait_queue on the drv_data->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 */ + drv_data->run = QUEUE_STOPPED; + while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) { + spin_unlock_irqrestore(&drv_data->lock, flags); + msleep(10); + spin_lock_irqsave(&drv_data->lock, flags); + } + + if (!list_empty(&drv_data->queue) || drv_data->busy) + status = -EBUSY; + + spin_unlock_irqrestore(&drv_data->lock, flags); + + return status; +} + +static int destroy_queue(struct driver_data *drv_data) +{ + int status; + + status = stop_queue(drv_data); + if (status != 0) + return status; + + destroy_workqueue(drv_data->workqueue); + + return 0; +} + +static int pxa2xx_spi_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct pxa2xx_spi_master *platform_info; + struct spi_master *master; + struct driver_data *drv_data = 0; + struct resource *memory_resource; + int irq; + int status = 0; + + platform_info = dev->platform_data; + + if (platform_info->ssp_type == SSP_UNDEFINED) { + dev_err(&pdev->dev, "undefined SSP\n"); + return -ENODEV; + } + + /* Allocate master with space for drv_data and null dma buffer */ + master = spi_alloc_master(dev, sizeof(struct driver_data) + 16); + if (!master) { + dev_err(&pdev->dev, "can not alloc spi_master\n"); + return -ENOMEM; + } + drv_data = spi_master_get_devdata(master); + drv_data->master = master; + drv_data->master_info = platform_info; + drv_data->pdev = pdev; + + master->bus_num = pdev->id; + master->num_chipselect = platform_info->num_chipselect; + master->cleanup = cleanup; + master->setup = setup; + master->transfer = transfer; + + drv_data->ssp_type = platform_info->ssp_type; + drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data + + sizeof(struct driver_data)), 8); + + /* Setup register addresses */ + memory_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!memory_resource) { + dev_err(&pdev->dev, "memory resources not defined\n"); + status = -ENODEV; + goto out_error_master_alloc; + } + + drv_data->ioaddr = (void *)io_p2v(memory_resource->start); + drv_data->ssdr_physical = memory_resource->start + 0x00000010; + if (platform_info->ssp_type == PXA25x_SSP) { + drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE; + drv_data->dma_cr1 = 0; + drv_data->clear_sr = SSSR_ROR; + drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR; + } else { + drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE; + drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE; + drv_data->clear_sr = SSSR_ROR | SSSR_TINT; + drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR; + } + + /* Attach to IRQ */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "irq resource not defined\n"); + status = -ENODEV; + goto out_error_master_alloc; + } + + status = request_irq(irq, ssp_int, SA_INTERRUPT, dev->bus_id, drv_data); + if (status < 0) { + dev_err(&pdev->dev, "can not get IRQ\n"); + goto out_error_master_alloc; + } + + /* Setup DMA if requested */ + drv_data->tx_channel = -1; + drv_data->rx_channel = -1; + if (platform_info->enable_dma) { + + /* Get two DMA channels (rx and tx) */ + drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx", + DMA_PRIO_HIGH, + dma_handler, + drv_data); + if (drv_data->rx_channel < 0) { + dev_err(dev, "problem (%d) requesting rx channel\n", + drv_data->rx_channel); + status = -ENODEV; + goto out_error_irq_alloc; + } + drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx", + DMA_PRIO_MEDIUM, + dma_handler, + drv_data); + if (drv_data->tx_channel < 0) { + dev_err(dev, "problem (%d) requesting tx channel\n", + drv_data->tx_channel); + status = -ENODEV; + goto out_error_dma_alloc; + } + + if (drv_data->ioaddr == SSP1_VIRT) { + DRCMRRXSSDR = DRCMR_MAPVLD + | drv_data->rx_channel; + DRCMRTXSSDR = DRCMR_MAPVLD + | drv_data->tx_channel; + } else if (drv_data->ioaddr == SSP2_VIRT) { + DRCMRRXSS2DR = DRCMR_MAPVLD + | drv_data->rx_channel; + DRCMRTXSS2DR = DRCMR_MAPVLD + | drv_data->tx_channel; + } else if (drv_data->ioaddr == SSP3_VIRT) { + DRCMRRXSS3DR = DRCMR_MAPVLD + | drv_data->rx_channel; + DRCMRTXSS3DR = DRCMR_MAPVLD + | drv_data->tx_channel; + } else { + dev_err(dev, "bad SSP type\n"); + goto out_error_dma_alloc; + } + } + + /* Enable SOC clock */ + pxa_set_cken(platform_info->clock_enable, 1); + + /* Load default SSP configuration */ + write_SSCR0(0, drv_data->ioaddr); + write_SSCR1(SSCR1_RxTresh(4) | SSCR1_TxTresh(12), drv_data->ioaddr); + write_SSCR0(SSCR0_SerClkDiv(2) + | SSCR0_Motorola + | SSCR0_DataSize(8), + drv_data->ioaddr); + if (drv_data->ssp_type != PXA25x_SSP) + write_SSTO(0, drv_data->ioaddr); + write_SSPSP(0, drv_data->ioaddr); + + /* Initial and start queue */ + status = init_queue(drv_data); + if (status != 0) { + dev_err(&pdev->dev, "problem initializing queue\n"); + goto out_error_clock_enabled; + } + status = start_queue(drv_data); + if (status != 0) { + dev_err(&pdev->dev, "problem starting queue\n"); + goto out_error_clock_enabled; + } + + /* Register with the SPI framework */ + platform_set_drvdata(pdev, drv_data); + status = spi_register_master(master); + if (status != 0) { + dev_err(&pdev->dev, "problem registering spi master\n"); + goto out_error_queue_alloc; + } + + return status; + +out_error_queue_alloc: + destroy_queue(drv_data); + +out_error_clock_enabled: + pxa_set_cken(platform_info->clock_enable, 0); + +out_error_dma_alloc: + if (drv_data->tx_channel != -1) + pxa_free_dma(drv_data->tx_channel); + if (drv_data->rx_channel != -1) + pxa_free_dma(drv_data->rx_channel); + +out_error_irq_alloc: + free_irq(irq, drv_data); + +out_error_master_alloc: + spi_master_put(master); + return status; +} + +static int pxa2xx_spi_remove(struct platform_device *pdev) +{ + struct driver_data *drv_data = platform_get_drvdata(pdev); + int irq; + int status = 0; + + if (!drv_data) + return 0; + + /* Remove the queue */ + status = destroy_queue(drv_data); + if (status != 0) + return status; + + /* Disable the SSP at the peripheral and SOC level */ + write_SSCR0(0, drv_data->ioaddr); + pxa_set_cken(drv_data->master_info->clock_enable, 0); + + /* Release DMA */ + if (drv_data->master_info->enable_dma) { + if (drv_data->ioaddr == SSP1_VIRT) { + DRCMRRXSSDR = 0; + DRCMRTXSSDR = 0; + } else if (drv_data->ioaddr == SSP2_VIRT) { + DRCMRRXSS2DR = 0; + DRCMRTXSS2DR = 0; + } else if (drv_data->ioaddr == SSP3_VIRT) { + DRCMRRXSS3DR = 0; + DRCMRTXSS3DR = 0; + } + pxa_free_dma(drv_data->tx_channel); + pxa_free_dma(drv_data->rx_channel); + } + + /* Release IRQ */ + irq = platform_get_irq(pdev, 0); + if (irq >= 0) + free_irq(irq, drv_data); + + /* Disconnect from the SPI framework */ + spi_unregister_master(drv_data->master); + + /* Prevent double remove */ + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static void pxa2xx_spi_shutdown(struct platform_device *pdev) +{ + int status = 0; + + if ((status = pxa2xx_spi_remove(pdev)) != 0) + dev_err(&pdev->dev, "shutdown failed with %d\n", status); +} + +#ifdef CONFIG_PM +static int suspend_devices(struct device *dev, void *pm_message) +{ + pm_message_t *state = pm_message; + + if (dev->power.power_state.event != state->event) { + dev_warn(dev, "pm state does not match request\n"); + return -1; + } + + return 0; +} + +static int pxa2xx_spi_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct driver_data *drv_data = platform_get_drvdata(pdev); + int status = 0; + + /* Check all childern for current power state */ + if (device_for_each_child(&pdev->dev, &state, suspend_devices) != 0) { + dev_warn(&pdev->dev, "suspend aborted\n"); + return -1; + } + + status = stop_queue(drv_data); + if (status != 0) + return status; + write_SSCR0(0, drv_data->ioaddr); + pxa_set_cken(drv_data->master_info->clock_enable, 0); + + return 0; +} + +static int pxa2xx_spi_resume(struct platform_device *pdev) +{ + struct driver_data *drv_data = platform_get_drvdata(pdev); + int status = 0; + + /* Enable the SSP clock */ + pxa_set_cken(drv_data->master_info->clock_enable, 1); + + /* Start the queue running */ + status = start_queue(drv_data); + if (status != 0) { + dev_err(&pdev->dev, "problem starting queue (%d)\n", status); + return status; + } + + return 0; +} +#else +#define pxa2xx_spi_suspend NULL +#define pxa2xx_spi_resume NULL +#endif /* CONFIG_PM */ + +static struct platform_driver driver = { + .driver = { + .name = "pxa2xx-spi", + .bus = &platform_bus_type, + .owner = THIS_MODULE, + }, + .probe = pxa2xx_spi_probe, + .remove = __devexit_p(pxa2xx_spi_remove), + .shutdown = pxa2xx_spi_shutdown, + .suspend = pxa2xx_spi_suspend, + .resume = pxa2xx_spi_resume, +}; + +static int __init pxa2xx_spi_init(void) +{ + platform_driver_register(&driver); + + return 0; +} +module_init(pxa2xx_spi_init); + +static void __exit pxa2xx_spi_exit(void) +{ + platform_driver_unregister(&driver); +} +module_exit(pxa2xx_spi_exit); |