/* * 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. * * 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 #include #include #include #include #include #include #include #include /* I2C controller revisions */ #define OMAP_I2C_REV_2 0x20 /* I2C controller revisions present on specific hardware */ #define OMAP_I2C_REV_ON_2430 0x36 #define OMAP_I2C_REV_ON_3430 0x3C /* timeout waiting for the controller to respond */ #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000)) #define OMAP_I2C_REV_REG 0x00 #define OMAP_I2C_IE_REG 0x04 #define OMAP_I2C_STAT_REG 0x08 #define OMAP_I2C_IV_REG 0x0c /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */ #define OMAP_I2C_WE_REG 0x0c #define OMAP_I2C_SYSS_REG 0x10 #define OMAP_I2C_BUF_REG 0x14 #define OMAP_I2C_CNT_REG 0x18 #define OMAP_I2C_DATA_REG 0x1c #define OMAP_I2C_SYSC_REG 0x20 #define OMAP_I2C_CON_REG 0x24 #define OMAP_I2C_OA_REG 0x28 #define OMAP_I2C_SA_REG 0x2c #define OMAP_I2C_PSC_REG 0x30 #define OMAP_I2C_SCLL_REG 0x34 #define OMAP_I2C_SCLH_REG 0x38 #define OMAP_I2C_SYSTEST_REG 0x3c #define OMAP_I2C_BUFSTAT_REG 0x40 /* 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 struct omap_i2c_dev { struct device *dev; void __iomem *base; /* virtual */ int irq; struct clk *iclk; /* Interface clock */ struct clk *fclk; /* Functional clock */ struct completion cmd_complete; struct resource *ioarea; u32 speed; /* Speed of bus in Khz */ u16 cmd_err; u8 *buf; size_t buf_len; struct i2c_adapter adapter; u8 fifo_size; /* use as flag and value * fifo_size==0 implies no fifo * if set, should be trsh+1 */ u8 rev; unsigned b_hw:1; /* bad h/w fixes */ unsigned idle:1; u16 iestate; /* Saved interrupt register */ u16 pscstate; u16 scllstate; u16 sclhstate; u16 bufstate; u16 syscstate; u16 westate; }; static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev, int reg, u16 val) { __raw_writew(val, i2c_dev->base + reg); } static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg) { return __raw_readw(i2c_dev->base + reg); } static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev) { int ret; dev->iclk = clk_get(dev->dev, "ick"); if (IS_ERR(dev->iclk)) { ret = PTR_ERR(dev->iclk); dev->iclk = NULL; return ret; } dev->fclk = clk_get(dev->dev, "fck"); if (IS_ERR(dev->fclk)) { ret = PTR_ERR(dev->fclk); if (dev->iclk != NULL) { clk_put(dev->iclk); dev->iclk = NULL; } dev->fclk = NULL; return ret; } return 0; } static void omap_i2c_put_clocks(struct omap_i2c_dev *dev) { clk_put(dev->fclk); dev->fclk = NULL; clk_put(dev->iclk); dev->iclk = NULL; } static void omap_i2c_unidle(struct omap_i2c_dev *dev) { WARN_ON(!dev->idle); clk_enable(dev->iclk); clk_enable(dev->fclk); if (cpu_is_omap34xx()) { omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate); omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate); omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate); omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate); omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, dev->syscstate); omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate); omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); } dev->idle = 0; /* * 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 void omap_i2c_idle(struct omap_i2c_dev *dev) { u16 iv; WARN_ON(dev->idle); dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0); if (dev->rev < OMAP_I2C_REV_2) { iv = 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 before the dev->idle store occurs */ omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); } dev->idle = 1; clk_disable(dev->fclk); clk_disable(dev->iclk); } static int omap_i2c_init(struct omap_i2c_dev *dev) { u16 psc = 0, scll = 0, sclh = 0, buf = 0; u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0; unsigned long fclk_rate = 12000000; unsigned long timeout; unsigned long internal_clk = 0; if (dev->rev >= OMAP_I2C_REV_2) { 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 */ if (dev->rev == OMAP_I2C_REV_ON_2430) { omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_AUTOIDLE_MASK); } else if (dev->rev >= OMAP_I2C_REV_ON_3430) { dev->syscstate = SYSC_AUTOIDLE_MASK; dev->syscstate |= SYSC_ENAWAKEUP_MASK; dev->syscstate |= (SYSC_IDLEMODE_SMART << __ffs(SYSC_SIDLEMODE_MASK)); dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK << __ffs(SYSC_CLOCKACTIVITY_MASK)); omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, dev->syscstate); /* * 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; omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate); } } omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); if (cpu_class_is_omap1()) { /* * 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_rate = clk_get_rate(dev->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 (cpu_is_omap2430() || cpu_is_omap34xx()) { /* * 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 || cpu_is_omap2430()) internal_clk = 19200; else if (dev->speed > 100) internal_clk = 9600; else internal_clk = 4000; fclk_rate = clk_get_rate(dev->fclk) / 1000; /* 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; } /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc); /* SCL low and high time values */ omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll); omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh); if (dev->fifo_size) { /* Note: setup required fifo size - 1. RTRSH and XTRSH */ buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR | (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR; omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf); } /* Take the I2C module out of reset: */ omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); /* Enable interrupts */ 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); omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate); if (cpu_is_omap34xx()) { dev->pscstate = psc; dev->scllstate = scll; dev->sclhstate = sclh; dev->bufstate = buf; } 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; } /* * 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); int r; 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; 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; 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); init_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_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. */ r = wait_for_completion_timeout(&dev->cmd_complete, OMAP_I2C_TIMEOUT); dev->buf_len = 0; if (r < 0) return r; if (r == 0) { dev_err(dev->dev, "controller timed out\n"); 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_init(dev); return -EIO; } if (dev->cmd_err & OMAP_I2C_STAT_NACK) { if (msg->flags & I2C_M_IGNORE_NAK) return 0; if (stop) { 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; omap_i2c_unidle(dev); r = omap_i2c_wait_for_bb(dev); if (r < 0) goto out; 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; out: omap_i2c_idle(dev); return r; } static u32 omap_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); } 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); } /* rev1 devices are apparently only on some 15xx */ #ifdef CONFIG_ARCH_OMAP15XX static irqreturn_t omap_i2c_rev1_isr(int this_irq, void *dev_id) { struct omap_i2c_dev *dev = dev_id; u16 iv, w; if (dev->idle) 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_rev1_isr NULL #endif static irqreturn_t omap_i2c_isr(int this_irq, void *dev_id) { struct omap_i2c_dev *dev = dev_id; u16 bits; u16 stat, w; int err, count = 0; if (dev->idle) return IRQ_NONE; bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) { 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; } err = 0; complete: /* * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be * acked after the data operation is complete. * Ref: TRM SWPU114Q Figure 18-31 */ omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat & ~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); if (stat & OMAP_I2C_STAT_NACK) { err |= OMAP_I2C_STAT_NACK; omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP); } if (stat & OMAP_I2C_STAT_AL) { dev_err(dev->dev, "Arbitration lost\n"); err |= OMAP_I2C_STAT_AL; } if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); omap_i2c_complete_cmd(dev, err); return IRQ_HANDLED; } if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) { u8 num_bytes = 1; if (dev->fifo_size) { if (stat & OMAP_I2C_STAT_RRDY) num_bytes = dev->fifo_size; else /* read RXSTAT on RDR interrupt */ num_bytes = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F; } while (num_bytes) { num_bytes--; w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG); if (dev->buf_len) { *dev->buf++ = w; dev->buf_len--; /* Data reg from 2430 is 8 bit wide */ if (!cpu_is_omap2430() && !cpu_is_omap34xx()) { if (dev->buf_len) { *dev->buf++ = w >> 8; dev->buf_len--; } } } else { if (stat & OMAP_I2C_STAT_RRDY) dev_err(dev->dev, "RRDY IRQ while no data" " requested\n"); if (stat & OMAP_I2C_STAT_RDR) dev_err(dev->dev, "RDR IRQ while no data" " requested\n"); break; } } omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)); continue; } if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) { u8 num_bytes = 1; if (dev->fifo_size) { if (stat & OMAP_I2C_STAT_XRDY) num_bytes = dev->fifo_size; else /* read TXSTAT on XDR interrupt */ num_bytes = omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) & 0x3F; } while (num_bytes) { num_bytes--; w = 0; if (dev->buf_len) { w = *dev->buf++; dev->buf_len--; /* Data reg from 2430 is 8 bit wide */ if (!cpu_is_omap2430() && !cpu_is_omap34xx()) { if (dev->buf_len) { w |= *dev->buf++ << 8; dev->buf_len--; } } } else { if (stat & OMAP_I2C_STAT_XRDY) dev_err(dev->dev, "XRDY IRQ while no " "data to send\n"); if (stat & OMAP_I2C_STAT_XDR) dev_err(dev->dev, "XDR IRQ while no " "data to send\n"); break; } /* * OMAP3430 Errata 1.153: 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. */ if (dev->rev <= OMAP_I2C_REV_ON_3430) { while (!(stat & OMAP_I2C_STAT_XUDF)) { if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); err |= OMAP_I2C_STAT_XUDF; goto complete; } cpu_relax(); stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); } } omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); } omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); continue; } if (stat & OMAP_I2C_STAT_ROVR) { dev_err(dev->dev, "Receive overrun\n"); dev->cmd_err |= OMAP_I2C_STAT_ROVR; } if (stat & OMAP_I2C_STAT_XUDF) { dev_err(dev->dev, "Transmit underflow\n"); dev->cmd_err |= OMAP_I2C_STAT_XUDF; } } return count ? IRQ_HANDLED : IRQ_NONE; } static const struct i2c_algorithm omap_i2c_algo = { .master_xfer = omap_i2c_xfer, .functionality = omap_i2c_func, }; static int __init omap_i2c_probe(struct platform_device *pdev) { struct omap_i2c_dev *dev; struct i2c_adapter *adap; struct resource *mem, *irq, *ioarea; irq_handler_t isr; int r; u32 speed = 0; /* NOTE: driver uses the static register mapping */ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!mem) { dev_err(&pdev->dev, "no mem resource?\n"); return -ENODEV; } irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (!irq) { dev_err(&pdev->dev, "no irq resource?\n"); return -ENODEV; } ioarea = request_mem_region(mem->start, resource_size(mem), pdev->name); if (!ioarea) { dev_err(&pdev->dev, "I2C region already claimed\n"); return -EBUSY; } dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL); if (!dev) { r = -ENOMEM; goto err_release_region; } if (pdev->dev.platform_data != NULL) speed = *(u32 *)pdev->dev.platform_data; else speed = 100; /* Defualt speed */ dev->speed = speed; dev->idle = 1; dev->dev = &pdev->dev; dev->irq = irq->start; dev->base = ioremap(mem->start, resource_size(mem)); if (!dev->base) { r = -ENOMEM; goto err_free_mem; } platform_set_drvdata(pdev, dev); if ((r = omap_i2c_get_clocks(dev)) != 0) goto err_iounmap; omap_i2c_unidle(dev); dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff; if (cpu_is_omap2430() || cpu_is_omap34xx()) { 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); dev->b_hw = 1; /* Enable hardware fixes */ } /* reset ASAP, clearing any IRQs */ omap_i2c_init(dev); isr = (dev->rev < OMAP_I2C_REV_2) ? omap_i2c_rev1_isr : omap_i2c_isr; r = request_irq(dev->irq, isr, 0, pdev->name, dev); if (r) { dev_err(dev->dev, "failure requesting irq %i\n", dev->irq); goto err_unuse_clocks; } dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", pdev->id, dev->rev >> 4, dev->rev & 0xf, dev->speed); omap_i2c_idle(dev); adap = &dev->adapter; i2c_set_adapdata(adap, dev); adap->owner = THIS_MODULE; adap->class = I2C_CLASS_HWMON; strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name)); adap->algo = &omap_i2c_algo; adap->dev.parent = &pdev->dev; /* 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_free_irq; } return 0; err_free_irq: free_irq(dev->irq, dev); err_unuse_clocks: omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); omap_i2c_idle(dev); omap_i2c_put_clocks(dev); err_iounmap: iounmap(dev->base); err_free_mem: platform_set_drvdata(pdev, NULL); kfree(dev); err_release_region: release_mem_region(mem->start, resource_size(mem)); return r; } static int omap_i2c_remove(struct platform_device *pdev) { struct omap_i2c_dev *dev = platform_get_drvdata(pdev); struct resource *mem; platform_set_drvdata(pdev, NULL); free_irq(dev->irq, dev); i2c_del_adapter(&dev->adapter); omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); omap_i2c_put_clocks(dev); iounmap(dev->base); kfree(dev); mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); release_mem_region(mem->start, resource_size(mem)); return 0; } static struct platform_driver omap_i2c_driver = { .probe = omap_i2c_probe, .remove = omap_i2c_remove, .driver = { .name = "i2c_omap", .owner = THIS_MODULE, }, }; /* 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:i2c_omap");