/* * TI OMAP I2C master mode driver * * Copyright (C) 2003 MontaVista Software, Inc. * Copyright (C) 2005 Nokia Corporation * Copyright (C) 2004 - 2007 Texas Instruments. * * Originally written by MontaVista Software, Inc. * Additional contributions by: * Tony Lindgren * Imre Deak * Juha Yrjölä * Syed Khasim * Nishant Menon * * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* I2C controller revisions */ #define OMAP_I2C_OMAP1_REV_2 0x20 /* I2C controller revisions present on specific hardware */ #define OMAP_I2C_REV_ON_2430 0x00000036 #define OMAP_I2C_REV_ON_3430_3530 0x0000003C #define OMAP_I2C_REV_ON_3630 0x00000040 #define OMAP_I2C_REV_ON_4430_PLUS 0x50400002 /* timeout waiting for the controller to respond */ #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000)) /* timeout for pm runtime autosuspend */ #define OMAP_I2C_PM_TIMEOUT 1000 /* ms */ /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */ enum { OMAP_I2C_REV_REG = 0, OMAP_I2C_IE_REG, OMAP_I2C_STAT_REG, OMAP_I2C_IV_REG, OMAP_I2C_WE_REG, OMAP_I2C_SYSS_REG, OMAP_I2C_BUF_REG, OMAP_I2C_CNT_REG, OMAP_I2C_DATA_REG, OMAP_I2C_SYSC_REG, OMAP_I2C_CON_REG, OMAP_I2C_OA_REG, OMAP_I2C_SA_REG, OMAP_I2C_PSC_REG, OMAP_I2C_SCLL_REG, OMAP_I2C_SCLH_REG, OMAP_I2C_SYSTEST_REG, OMAP_I2C_BUFSTAT_REG, /* only on OMAP4430 */ OMAP_I2C_IP_V2_REVNB_LO, OMAP_I2C_IP_V2_REVNB_HI, OMAP_I2C_IP_V2_IRQSTATUS_RAW, OMAP_I2C_IP_V2_IRQENABLE_SET, OMAP_I2C_IP_V2_IRQENABLE_CLR, }; /* I2C Interrupt Enable Register (OMAP_I2C_IE): */ #define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */ #define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */ #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */ #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */ #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */ #define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */ #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */ /* I2C Status Register (OMAP_I2C_STAT): */ #define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */ #define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */ #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */ #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */ #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */ #define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */ #define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */ #define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */ #define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */ #define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */ #define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */ #define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */ /* I2C WE wakeup enable register */ #define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */ #define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */ #define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/ #define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */ #define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */ #define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */ #define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */ #define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */ #define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */ #define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */ #define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \ OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \ OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \ OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \ OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE) /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */ #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */ #define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */ #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */ #define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */ /* I2C Configuration Register (OMAP_I2C_CON): */ #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */ #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */ #define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */ #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */ #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */ #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */ #define OMAP_I2C_CON_XA (1 << 8) /* Expand address */ #define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */ #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */ #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */ /* I2C SCL time value when Master */ #define OMAP_I2C_SCLL_HSSCLL 8 #define OMAP_I2C_SCLH_HSSCLH 8 /* I2C System Test Register (OMAP_I2C_SYSTEST): */ #ifdef DEBUG #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */ #define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */ #define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */ #define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */ #define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */ #define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */ #define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */ #define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */ #endif /* OCP_SYSSTATUS bit definitions */ #define SYSS_RESETDONE_MASK (1 << 0) /* OCP_SYSCONFIG bit definitions */ #define SYSC_CLOCKACTIVITY_MASK (0x3 << 8) #define SYSC_SIDLEMODE_MASK (0x3 << 3) #define SYSC_ENAWAKEUP_MASK (1 << 2) #define SYSC_SOFTRESET_MASK (1 << 1) #define SYSC_AUTOIDLE_MASK (1 << 0) #define SYSC_IDLEMODE_SMART 0x2 #define SYSC_CLOCKACTIVITY_FCLK 0x2 /* Errata definitions */ #define I2C_OMAP_ERRATA_I207 (1 << 0) #define I2C_OMAP_ERRATA_I462 (1 << 1) #define OMAP_I2C_IP_V2_INTERRUPTS_MASK 0x6FFF struct omap_i2c_dev { spinlock_t lock; /* IRQ synchronization */ struct device *dev; void __iomem *base; /* virtual */ int irq; int reg_shift; /* bit shift for I2C register addresses */ struct completion cmd_complete; struct resource *ioarea; u32 latency; /* maximum mpu wkup latency */ void (*set_mpu_wkup_lat)(struct device *dev, long latency); u32 speed; /* Speed of bus in kHz */ u32 flags; u16 scheme; u16 cmd_err; u8 *buf; u8 *regs; size_t buf_len; struct i2c_adapter adapter; u8 threshold; u8 fifo_size; /* use as flag and value * fifo_size==0 implies no fifo * if set, should be trsh+1 */ u32 rev; unsigned b_hw:1; /* bad h/w fixes */ unsigned receiver:1; /* true when we're in receiver mode */ u16 iestate; /* Saved interrupt register */ u16 pscstate; u16 scllstate; u16 sclhstate; u16 syscstate; u16 westate; u16 errata; }; static const u8 reg_map_ip_v1[] = { [OMAP_I2C_REV_REG] = 0x00, [OMAP_I2C_IE_REG] = 0x01, [OMAP_I2C_STAT_REG] = 0x02, [OMAP_I2C_IV_REG] = 0x03, [OMAP_I2C_WE_REG] = 0x03, [OMAP_I2C_SYSS_REG] = 0x04, [OMAP_I2C_BUF_REG] = 0x05, [OMAP_I2C_CNT_REG] = 0x06, [OMAP_I2C_DATA_REG] = 0x07, [OMAP_I2C_SYSC_REG] = 0x08, [OMAP_I2C_CON_REG] = 0x09, [OMAP_I2C_OA_REG] = 0x0a, [OMAP_I2C_SA_REG] = 0x0b, [OMAP_I2C_PSC_REG] = 0x0c, [OMAP_I2C_SCLL_REG] = 0x0d, [OMAP_I2C_SCLH_REG] = 0x0e, [OMAP_I2C_SYSTEST_REG] = 0x0f, [OMAP_I2C_BUFSTAT_REG] = 0x10, }; static const u8 reg_map_ip_v2[] = { [OMAP_I2C_REV_REG] = 0x04, [OMAP_I2C_IE_REG] = 0x2c, [OMAP_I2C_STAT_REG] = 0x28, [OMAP_I2C_IV_REG] = 0x34, [OMAP_I2C_WE_REG] = 0x34, [OMAP_I2C_SYSS_REG] = 0x90, [OMAP_I2C_BUF_REG] = 0x94, [OMAP_I2C_CNT_REG] = 0x98, [OMAP_I2C_DATA_REG] = 0x9c, [OMAP_I2C_SYSC_REG] = 0x10, [OMAP_I2C_CON_REG] = 0xa4, [OMAP_I2C_OA_REG] = 0xa8, [OMAP_I2C_SA_REG] = 0xac, [OMAP_I2C_PSC_REG] = 0xb0, [OMAP_I2C_SCLL_REG] = 0xb4, [OMAP_I2C_SCLH_REG] = 0xb8, [OMAP_I2C_SYSTEST_REG] = 0xbC, [OMAP_I2C_BUFSTAT_REG] = 0xc0, [OMAP_I2C_IP_V2_REVNB_LO] = 0x00, [OMAP_I2C_IP_V2_REVNB_HI] = 0x04, [OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24, [OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c, [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30, }; static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev, int reg, u16 val) { writew_relaxed(val, i2c_dev->base + (i2c_dev->regs[reg] << i2c_dev->reg_shift)); } static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg) { return readw_relaxed(i2c_dev->base + (i2c_dev->regs[reg] << i2c_dev->reg_shift)); } static void __omap_i2c_init(struct omap_i2c_dev *dev) { omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate); /* SCL low and high time values */ omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate); omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate); if (dev->rev >= OMAP_I2C_REV_ON_3430_3530) omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate); /* Take the I2C module out of reset: */ omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); /* * Don't write to this register if the IE state is 0 as it can * cause deadlock. */ if (dev->iestate) omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate); } static int omap_i2c_reset(struct omap_i2c_dev *dev) { unsigned long timeout; u16 sysc; if (dev->rev >= OMAP_I2C_OMAP1_REV_2) { sysc = omap_i2c_read_reg(dev, OMAP_I2C_SYSC_REG); /* Disable I2C controller before soft reset */ omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) & ~(OMAP_I2C_CON_EN)); omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK); /* For some reason we need to set the EN bit before the * reset done bit gets set. */ timeout = jiffies + OMAP_I2C_TIMEOUT; omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) & SYSS_RESETDONE_MASK)) { if (time_after(jiffies, timeout)) { dev_warn(dev->dev, "timeout waiting " "for controller reset\n"); return -ETIMEDOUT; } msleep(1); } /* SYSC register is cleared by the reset; rewrite it */ omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, sysc); } return 0; } static int omap_i2c_init(struct omap_i2c_dev *dev) { u16 psc = 0, scll = 0, sclh = 0; u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0; unsigned long fclk_rate = 12000000; unsigned long internal_clk = 0; struct clk *fclk; if (dev->rev >= OMAP_I2C_REV_ON_3430_3530) { /* * Enabling all wakup sources to stop I2C freezing on * WFI instruction. * REVISIT: Some wkup sources might not be needed. */ dev->westate = OMAP_I2C_WE_ALL; } if (dev->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) { /* * The I2C functional clock is the armxor_ck, so there's * no need to get "armxor_ck" separately. Now, if OMAP2420 * always returns 12MHz for the functional clock, we can * do this bit unconditionally. */ fclk = clk_get(dev->dev, "fck"); fclk_rate = clk_get_rate(fclk); clk_put(fclk); /* TRM for 5912 says the I2C clock must be prescaled to be * between 7 - 12 MHz. The XOR input clock is typically * 12, 13 or 19.2 MHz. So we should have code that produces: * * XOR MHz Divider Prescaler * 12 1 0 * 13 2 1 * 19.2 2 1 */ if (fclk_rate > 12000000) psc = fclk_rate / 12000000; } if (!(dev->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) { /* * HSI2C controller internal clk rate should be 19.2 Mhz for * HS and for all modes on 2430. On 34xx we can use lower rate * to get longer filter period for better noise suppression. * The filter is iclk (fclk for HS) period. */ if (dev->speed > 400 || dev->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK) internal_clk = 19200; else if (dev->speed > 100) internal_clk = 9600; else internal_clk = 4000; fclk = clk_get(dev->dev, "fck"); fclk_rate = clk_get_rate(fclk) / 1000; clk_put(fclk); /* Compute prescaler divisor */ psc = fclk_rate / internal_clk; psc = psc - 1; /* If configured for High Speed */ if (dev->speed > 400) { unsigned long scl; /* For first phase of HS mode */ scl = internal_clk / 400; fsscll = scl - (scl / 3) - 7; fssclh = (scl / 3) - 5; /* For second phase of HS mode */ scl = fclk_rate / dev->speed; hsscll = scl - (scl / 3) - 7; hssclh = (scl / 3) - 5; } else if (dev->speed > 100) { unsigned long scl; /* Fast mode */ scl = internal_clk / dev->speed; fsscll = scl - (scl / 3) - 7; fssclh = (scl / 3) - 5; } else { /* Standard mode */ fsscll = internal_clk / (dev->speed * 2) - 7; fssclh = internal_clk / (dev->speed * 2) - 5; } scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll; sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh; } else { /* Program desired operating rate */ fclk_rate /= (psc + 1) * 1000; if (psc > 2) psc = 2; scll = fclk_rate / (dev->speed * 2) - 7 + psc; sclh = fclk_rate / (dev->speed * 2) - 7 + psc; } dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | OMAP_I2C_IE_AL) | ((dev->fifo_size) ? (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0); dev->pscstate = psc; dev->scllstate = scll; dev->sclhstate = sclh; __omap_i2c_init(dev); return 0; } /* * Waiting on Bus Busy */ static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev) { unsigned long timeout; timeout = jiffies + OMAP_I2C_TIMEOUT; while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) { if (time_after(jiffies, timeout)) { dev_warn(dev->dev, "timeout waiting for bus ready\n"); return -ETIMEDOUT; } msleep(1); } return 0; } static void omap_i2c_resize_fifo(struct omap_i2c_dev *dev, u8 size, bool is_rx) { u16 buf; if (dev->flags & OMAP_I2C_FLAG_NO_FIFO) return; /* * Set up notification threshold based on message size. We're doing * this to try and avoid draining feature as much as possible. Whenever * we have big messages to transfer (bigger than our total fifo size) * then we might use draining feature to transfer the remaining bytes. */ dev->threshold = clamp(size, (u8) 1, dev->fifo_size); buf = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG); if (is_rx) { /* Clear RX Threshold */ buf &= ~(0x3f << 8); buf |= ((dev->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR; } else { /* Clear TX Threshold */ buf &= ~0x3f; buf |= (dev->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR; } omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf); if (dev->rev < OMAP_I2C_REV_ON_3630) dev->b_hw = 1; /* Enable hardware fixes */ /* calculate wakeup latency constraint for MPU */ if (dev->set_mpu_wkup_lat != NULL) dev->latency = (1000000 * dev->threshold) / (1000 * dev->speed / 8); } /* * Low level master read/write transaction. */ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) { struct omap_i2c_dev *dev = i2c_get_adapdata(adap); unsigned long timeout; u16 w; dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", msg->addr, msg->len, msg->flags, stop); if (msg->len == 0) return -EINVAL; dev->receiver = !!(msg->flags & I2C_M_RD); omap_i2c_resize_fifo(dev, msg->len, dev->receiver); omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr); /* REVISIT: Could the STB bit of I2C_CON be used with probing? */ dev->buf = msg->buf; dev->buf_len = msg->len; /* make sure writes to dev->buf_len are ordered */ barrier(); omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len); /* Clear the FIFO Buffers */ w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG); w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR; omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w); reinit_completion(&dev->cmd_complete); dev->cmd_err = 0; w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; /* High speed configuration */ if (dev->speed > 400) w |= OMAP_I2C_CON_OPMODE_HS; if (msg->flags & I2C_M_STOP) stop = 1; if (msg->flags & I2C_M_TEN) w |= OMAP_I2C_CON_XA; if (!(msg->flags & I2C_M_RD)) w |= OMAP_I2C_CON_TRX; if (!dev->b_hw && stop) w |= OMAP_I2C_CON_STP; omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); /* * Don't write stt and stp together on some hardware. */ if (dev->b_hw && stop) { unsigned long delay = jiffies + OMAP_I2C_TIMEOUT; u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG); while (con & OMAP_I2C_CON_STT) { con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG); /* Let the user know if i2c is in a bad state */ if (time_after(jiffies, delay)) { dev_err(dev->dev, "controller timed out " "waiting for start condition to finish\n"); return -ETIMEDOUT; } cpu_relax(); } w |= OMAP_I2C_CON_STP; w &= ~OMAP_I2C_CON_STT; omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); } /* * REVISIT: We should abort the transfer on signals, but the bus goes * into arbitration and we're currently unable to recover from it. */ timeout = wait_for_completion_timeout(&dev->cmd_complete, OMAP_I2C_TIMEOUT); if (timeout == 0) { dev_err(dev->dev, "controller timed out\n"); omap_i2c_reset(dev); __omap_i2c_init(dev); return -ETIMEDOUT; } if (likely(!dev->cmd_err)) return 0; /* We have an error */ if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) { omap_i2c_reset(dev); __omap_i2c_init(dev); return -EIO; } if (dev->cmd_err & OMAP_I2C_STAT_NACK) { if (msg->flags & I2C_M_IGNORE_NAK) return 0; w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG); w |= OMAP_I2C_CON_STP; omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); return -EREMOTEIO; } return -EIO; } /* * Prepare controller for a transaction and call omap_i2c_xfer_msg * to do the work during IRQ processing. */ static int omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct omap_i2c_dev *dev = i2c_get_adapdata(adap); int i; int r; r = pm_runtime_get_sync(dev->dev); if (r < 0) goto out; r = omap_i2c_wait_for_bb(dev); if (r < 0) goto out; if (dev->set_mpu_wkup_lat != NULL) dev->set_mpu_wkup_lat(dev->dev, dev->latency); for (i = 0; i < num; i++) { r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1))); if (r != 0) break; } if (r == 0) r = num; omap_i2c_wait_for_bb(dev); if (dev->set_mpu_wkup_lat != NULL) dev->set_mpu_wkup_lat(dev->dev, -1); out: pm_runtime_mark_last_busy(dev->dev); pm_runtime_put_autosuspend(dev->dev); return r; } static u32 omap_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | I2C_FUNC_PROTOCOL_MANGLING; } static inline void omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err) { dev->cmd_err |= err; complete(&dev->cmd_complete); } static inline void omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat) { omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); } static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat) { /* * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8) * Not applicable for OMAP4. * Under certain rare conditions, RDR could be set again * when the bus is busy, then ignore the interrupt and * clear the interrupt. */ if (stat & OMAP_I2C_STAT_RDR) { /* Step 1: If RDR is set, clear it */ omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR); /* Step 2: */ if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB)) { /* Step 3: */ if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_RDR) { omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR); dev_dbg(dev->dev, "RDR when bus is busy.\n"); } } } } /* rev1 devices are apparently only on some 15xx */ #ifdef CONFIG_ARCH_OMAP15XX static irqreturn_t omap_i2c_omap1_isr(int this_irq, void *dev_id) { struct omap_i2c_dev *dev = dev_id; u16 iv, w; if (pm_runtime_suspended(dev->dev)) return IRQ_NONE; iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); switch (iv) { case 0x00: /* None */ break; case 0x01: /* Arbitration lost */ dev_err(dev->dev, "Arbitration lost\n"); omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL); break; case 0x02: /* No acknowledgement */ omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK); omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP); break; case 0x03: /* Register access ready */ omap_i2c_complete_cmd(dev, 0); break; case 0x04: /* Receive data ready */ if (dev->buf_len) { w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG); *dev->buf++ = w; dev->buf_len--; if (dev->buf_len) { *dev->buf++ = w >> 8; dev->buf_len--; } } else dev_err(dev->dev, "RRDY IRQ while no data requested\n"); break; case 0x05: /* Transmit data ready */ if (dev->buf_len) { w = *dev->buf++; dev->buf_len--; if (dev->buf_len) { w |= *dev->buf++ << 8; dev->buf_len--; } omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); } else dev_err(dev->dev, "XRDY IRQ while no data to send\n"); break; default: return IRQ_NONE; } return IRQ_HANDLED; } #else #define omap_i2c_omap1_isr NULL #endif /* * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing * data to DATA_REG. Otherwise some data bytes can be lost while transferring * them from the memory to the I2C interface. */ static int errata_omap3_i462(struct omap_i2c_dev *dev) { unsigned long timeout = 10000; u16 stat; do { stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); if (stat & OMAP_I2C_STAT_XUDF) break; if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); if (stat & OMAP_I2C_STAT_NACK) { dev->cmd_err |= OMAP_I2C_STAT_NACK; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK); } if (stat & OMAP_I2C_STAT_AL) { dev_err(dev->dev, "Arbitration lost\n"); dev->cmd_err |= OMAP_I2C_STAT_AL; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL); } return -EIO; } cpu_relax(); } while (--timeout); if (!timeout) { dev_err(dev->dev, "timeout waiting on XUDF bit\n"); return 0; } return 0; } static void omap_i2c_receive_data(struct omap_i2c_dev *dev, u8 num_bytes, bool is_rdr) { u16 w; while (num_bytes--) { w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG); *dev->buf++ = w; dev->buf_len--; /* * Data reg in 2430, omap3 and * omap4 is 8 bit wide */ if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { *dev->buf++ = w >> 8; dev->buf_len--; } } } static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes, bool is_xdr) { u16 w; while (num_bytes--) { w = *dev->buf++; dev->buf_len--; /* * Data reg in 2430, omap3 and * omap4 is 8 bit wide */ if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { w |= *dev->buf++ << 8; dev->buf_len--; } if (dev->errata & I2C_OMAP_ERRATA_I462) { int ret; ret = errata_omap3_i462(dev); if (ret < 0) return ret; } omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); } return 0; } static irqreturn_t omap_i2c_isr(int irq, void *dev_id) { struct omap_i2c_dev *dev = dev_id; irqreturn_t ret = IRQ_HANDLED; u16 mask; u16 stat; spin_lock(&dev->lock); mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); if (stat & mask) ret = IRQ_WAKE_THREAD; spin_unlock(&dev->lock); return ret; } static irqreturn_t omap_i2c_isr_thread(int this_irq, void *dev_id) { struct omap_i2c_dev *dev = dev_id; unsigned long flags; u16 bits; u16 stat; int err = 0, count = 0; spin_lock_irqsave(&dev->lock, flags); do { bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); stat &= bits; /* If we're in receiver mode, ignore XDR/XRDY */ if (dev->receiver) stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY); else stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY); if (!stat) { /* my work here is done */ goto out; } dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat); if (count++ == 100) { dev_warn(dev->dev, "Too much work in one IRQ\n"); break; } if (stat & OMAP_I2C_STAT_NACK) { err |= OMAP_I2C_STAT_NACK; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK); } if (stat & OMAP_I2C_STAT_AL) { dev_err(dev->dev, "Arbitration lost\n"); err |= OMAP_I2C_STAT_AL; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL); } /* * ProDB0017052: Clear ARDY bit twice */ if (stat & OMAP_I2C_STAT_ARDY) omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ARDY); if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_ARDY)); break; } if (stat & OMAP_I2C_STAT_RDR) { u8 num_bytes = 1; if (dev->fifo_size) num_bytes = dev->buf_len; if (dev->errata & I2C_OMAP_ERRATA_I207) { i2c_omap_errata_i207(dev, stat); num_bytes = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F; } omap_i2c_receive_data(dev, num_bytes, true); omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR); continue; } if (stat & OMAP_I2C_STAT_RRDY) { u8 num_bytes = 1; if (dev->threshold) num_bytes = dev->threshold; omap_i2c_receive_data(dev, num_bytes, false); omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY); continue; } if (stat & OMAP_I2C_STAT_XDR) { u8 num_bytes = 1; int ret; if (dev->fifo_size) num_bytes = dev->buf_len; ret = omap_i2c_transmit_data(dev, num_bytes, true); if (ret < 0) break; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR); continue; } if (stat & OMAP_I2C_STAT_XRDY) { u8 num_bytes = 1; int ret; if (dev->threshold) num_bytes = dev->threshold; ret = omap_i2c_transmit_data(dev, num_bytes, false); if (ret < 0) break; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY); continue; } if (stat & OMAP_I2C_STAT_ROVR) { dev_err(dev->dev, "Receive overrun\n"); err |= OMAP_I2C_STAT_ROVR; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ROVR); break; } if (stat & OMAP_I2C_STAT_XUDF) { dev_err(dev->dev, "Transmit underflow\n"); err |= OMAP_I2C_STAT_XUDF; omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XUDF); break; } } while (stat); omap_i2c_complete_cmd(dev, err); out: spin_unlock_irqrestore(&dev->lock, flags); return IRQ_HANDLED; } static const struct i2c_algorithm omap_i2c_algo = { .master_xfer = omap_i2c_xfer, .functionality = omap_i2c_func, }; #ifdef CONFIG_OF static struct omap_i2c_bus_platform_data omap2420_pdata = { .rev = OMAP_I2C_IP_VERSION_1, .flags = OMAP_I2C_FLAG_NO_FIFO | OMAP_I2C_FLAG_SIMPLE_CLOCK | OMAP_I2C_FLAG_16BIT_DATA_REG | OMAP_I2C_FLAG_BUS_SHIFT_2, }; static struct omap_i2c_bus_platform_data omap2430_pdata = { .rev = OMAP_I2C_IP_VERSION_1, .flags = OMAP_I2C_FLAG_BUS_SHIFT_2 | OMAP_I2C_FLAG_FORCE_19200_INT_CLK, }; static struct omap_i2c_bus_platform_data omap3_pdata = { .rev = OMAP_I2C_IP_VERSION_1, .flags = OMAP_I2C_FLAG_BUS_SHIFT_2, }; static struct omap_i2c_bus_platform_data omap4_pdata = { .rev = OMAP_I2C_IP_VERSION_2, }; static const struct of_device_id omap_i2c_of_match[] = { { .compatible = "ti,omap4-i2c", .data = &omap4_pdata, }, { .compatible = "ti,omap3-i2c", .data = &omap3_pdata, }, { .compatible = "ti,omap2430-i2c", .data = &omap2430_pdata, }, { .compatible = "ti,omap2420-i2c", .data = &omap2420_pdata, }, { }, }; MODULE_DEVICE_TABLE(of, omap_i2c_of_match); #endif #define OMAP_I2C_SCHEME(rev) ((rev & 0xc000) >> 14) #define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4) #define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf) #define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7) #define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f) #define OMAP_I2C_SCHEME_0 0 #define OMAP_I2C_SCHEME_1 1 static int omap_i2c_probe(struct platform_device *pdev) { struct omap_i2c_dev *dev; struct i2c_adapter *adap; struct resource *mem; const struct omap_i2c_bus_platform_data *pdata = dev_get_platdata(&pdev->dev); struct device_node *node = pdev->dev.of_node; const struct of_device_id *match; int irq; int r; u32 rev; u16 minor, major; irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "no irq resource?\n"); return irq; } dev = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL); if (!dev) return -ENOMEM; mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); dev->base = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(dev->base)) return PTR_ERR(dev->base); match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev); if (match) { u32 freq = 100000; /* default to 100000 Hz */ pdata = match->data; dev->flags = pdata->flags; of_property_read_u32(node, "clock-frequency", &freq); /* convert DT freq value in Hz into kHz for speed */ dev->speed = freq / 1000; } else if (pdata != NULL) { dev->speed = pdata->clkrate; dev->flags = pdata->flags; dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat; } dev->dev = &pdev->dev; dev->irq = irq; spin_lock_init(&dev->lock); platform_set_drvdata(pdev, dev); init_completion(&dev->cmd_complete); dev->reg_shift = (dev->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3; pm_runtime_enable(dev->dev); pm_runtime_set_autosuspend_delay(dev->dev, OMAP_I2C_PM_TIMEOUT); pm_runtime_use_autosuspend(dev->dev); r = pm_runtime_get_sync(dev->dev); if (r < 0) goto err_free_mem; /* * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2. * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset. * Also since the omap_i2c_read_reg uses reg_map_ip_* a * readw_relaxed is done. */ rev = readw_relaxed(dev->base + 0x04); dev->scheme = OMAP_I2C_SCHEME(rev); switch (dev->scheme) { case OMAP_I2C_SCHEME_0: dev->regs = (u8 *)reg_map_ip_v1; dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG); minor = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev); major = OMAP_I2C_REV_SCHEME_0_MAJOR(dev->rev); break; case OMAP_I2C_SCHEME_1: /* FALLTHROUGH */ default: dev->regs = (u8 *)reg_map_ip_v2; rev = (rev << 16) | omap_i2c_read_reg(dev, OMAP_I2C_IP_V2_REVNB_LO); minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev); major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev); dev->rev = rev; } dev->errata = 0; if (dev->rev >= OMAP_I2C_REV_ON_2430 && dev->rev < OMAP_I2C_REV_ON_4430_PLUS) dev->errata |= I2C_OMAP_ERRATA_I207; if (dev->rev <= OMAP_I2C_REV_ON_3430_3530) dev->errata |= I2C_OMAP_ERRATA_I462; if (!(dev->flags & OMAP_I2C_FLAG_NO_FIFO)) { u16 s; /* Set up the fifo size - Get total size */ s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3; dev->fifo_size = 0x8 << s; /* * Set up notification threshold as half the total available * size. This is to ensure that we can handle the status on int * call back latencies. */ dev->fifo_size = (dev->fifo_size / 2); if (dev->rev < OMAP_I2C_REV_ON_3630) dev->b_hw = 1; /* Enable hardware fixes */ /* calculate wakeup latency constraint for MPU */ if (dev->set_mpu_wkup_lat != NULL) dev->latency = (1000000 * dev->fifo_size) / (1000 * dev->speed / 8); } /* reset ASAP, clearing any IRQs */ omap_i2c_init(dev); if (dev->rev < OMAP_I2C_OMAP1_REV_2) r = devm_request_irq(&pdev->dev, dev->irq, omap_i2c_omap1_isr, IRQF_NO_SUSPEND, pdev->name, dev); else r = devm_request_threaded_irq(&pdev->dev, dev->irq, omap_i2c_isr, omap_i2c_isr_thread, IRQF_NO_SUSPEND | IRQF_ONESHOT, pdev->name, dev); if (r) { dev_err(dev->dev, "failure requesting irq %i\n", dev->irq); goto err_unuse_clocks; } adap = &dev->adapter; i2c_set_adapdata(adap, dev); adap->owner = THIS_MODULE; adap->class = I2C_CLASS_DEPRECATED; strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name)); adap->algo = &omap_i2c_algo; adap->dev.parent = &pdev->dev; adap->dev.of_node = pdev->dev.of_node; /* i2c device drivers may be active on return from add_adapter() */ adap->nr = pdev->id; r = i2c_add_numbered_adapter(adap); if (r) { dev_err(dev->dev, "failure adding adapter\n"); goto err_unuse_clocks; } dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr, major, minor, dev->speed); pm_runtime_mark_last_busy(dev->dev); pm_runtime_put_autosuspend(dev->dev); return 0; err_unuse_clocks: omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); pm_runtime_put(dev->dev); pm_runtime_disable(&pdev->dev); err_free_mem: return r; } static int omap_i2c_remove(struct platform_device *pdev) { struct omap_i2c_dev *dev = platform_get_drvdata(pdev); int ret; i2c_del_adapter(&dev->adapter); ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) return ret; omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); pm_runtime_put(&pdev->dev); pm_runtime_disable(&pdev->dev); return 0; } #ifdef CONFIG_PM static int omap_i2c_runtime_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct omap_i2c_dev *_dev = platform_get_drvdata(pdev); _dev->iestate = omap_i2c_read_reg(_dev, OMAP_I2C_IE_REG); if (_dev->scheme == OMAP_I2C_SCHEME_0) omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, 0); else omap_i2c_write_reg(_dev, OMAP_I2C_IP_V2_IRQENABLE_CLR, OMAP_I2C_IP_V2_INTERRUPTS_MASK); if (_dev->rev < OMAP_I2C_OMAP1_REV_2) { omap_i2c_read_reg(_dev, OMAP_I2C_IV_REG); /* Read clears */ } else { omap_i2c_write_reg(_dev, OMAP_I2C_STAT_REG, _dev->iestate); /* Flush posted write */ omap_i2c_read_reg(_dev, OMAP_I2C_STAT_REG); } return 0; } static int omap_i2c_runtime_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct omap_i2c_dev *_dev = platform_get_drvdata(pdev); if (!_dev->regs) return 0; __omap_i2c_init(_dev); return 0; } static struct dev_pm_ops omap_i2c_pm_ops = { SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend, omap_i2c_runtime_resume, NULL) }; #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops) #else #define OMAP_I2C_PM_OPS NULL #endif /* CONFIG_PM */ static struct platform_driver omap_i2c_driver = { .probe = omap_i2c_probe, .remove = omap_i2c_remove, .driver = { .name = "omap_i2c", .owner = THIS_MODULE, .pm = OMAP_I2C_PM_OPS, .of_match_table = of_match_ptr(omap_i2c_of_match), }, }; /* I2C may be needed to bring up other drivers */ static int __init omap_i2c_init_driver(void) { return platform_driver_register(&omap_i2c_driver); } subsys_initcall(omap_i2c_init_driver); static void __exit omap_i2c_exit_driver(void) { platform_driver_unregister(&omap_i2c_driver); } module_exit(omap_i2c_exit_driver); MODULE_AUTHOR("MontaVista Software, Inc. (and others)"); MODULE_DESCRIPTION("TI OMAP I2C bus adapter"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:omap_i2c");