diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-omap.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-omap.c | 1613 |
1 files changed, 1613 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c new file mode 100644 index 000000000..7ec252199 --- /dev/null +++ b/drivers/i2c/busses/i2c-omap.c @@ -0,0 +1,1613 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 <tony@atomide.com> + * Imre Deak <imre.deak@nokia.com> + * Juha Yrjölä <juha.yrjola@solidboot.com> + * Syed Khasim <x0khasim@ti.com> + * Nishant Menon <nm@ti.com> + */ + +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/completion.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/slab.h> +#include <linux/platform_data/i2c-omap.h> +#include <linux/pm_runtime.h> +#include <linux/pinctrl/consumer.h> + +/* 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 */ + +/* timeout for making decision on bus free status */ +#define OMAP_I2C_BUS_FREE_TIMEOUT (msecs_to_jiffies(10)) + +/* 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_BF (1 << 8) /* Bus Free */ +#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): */ +#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 */ +/* Functional mode */ +#define OMAP_I2C_SYSTEST_SCL_I_FUNC (1 << 8) /* SCL line input value */ +#define OMAP_I2C_SYSTEST_SCL_O_FUNC (1 << 7) /* SCL line output value */ +#define OMAP_I2C_SYSTEST_SDA_I_FUNC (1 << 6) /* SDA line input value */ +#define OMAP_I2C_SYSTEST_SDA_O_FUNC (1 << 5) /* SDA line output value */ +/* SDA/SCL IO mode */ +#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 */ + +/* 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 { + 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 bb_valid:1; /* true when BB-bit reflects + * the I2C bus state + */ + 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 int omap_i2c_xfer_data(struct omap_i2c_dev *omap); + +static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap, + int reg, u16 val) +{ + writew_relaxed(val, omap->base + + (omap->regs[reg] << omap->reg_shift)); +} + +static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *omap, int reg) +{ + return readw_relaxed(omap->base + + (omap->regs[reg] << omap->reg_shift)); +} + +static void __omap_i2c_init(struct omap_i2c_dev *omap) +{ + + omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); + + /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ + omap_i2c_write_reg(omap, OMAP_I2C_PSC_REG, omap->pscstate); + + /* SCL low and high time values */ + omap_i2c_write_reg(omap, OMAP_I2C_SCLL_REG, omap->scllstate); + omap_i2c_write_reg(omap, OMAP_I2C_SCLH_REG, omap->sclhstate); + if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) + omap_i2c_write_reg(omap, OMAP_I2C_WE_REG, omap->westate); + + /* Take the I2C module out of reset: */ + omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); + + /* + * NOTE: right after setting CON_EN, STAT_BB could be 0 while the + * bus is busy. It will be changed to 1 on the next IP FCLK clock. + * udelay(1) will be enough to fix that. + */ + + /* + * Don't write to this register if the IE state is 0 as it can + * cause deadlock. + */ + if (omap->iestate) + omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, omap->iestate); +} + +static int omap_i2c_reset(struct omap_i2c_dev *omap) +{ + unsigned long timeout; + u16 sysc; + + if (omap->rev >= OMAP_I2C_OMAP1_REV_2) { + sysc = omap_i2c_read_reg(omap, OMAP_I2C_SYSC_REG); + + /* Disable I2C controller before soft reset */ + omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, + omap_i2c_read_reg(omap, OMAP_I2C_CON_REG) & + ~(OMAP_I2C_CON_EN)); + + omap_i2c_write_reg(omap, 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(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); + while (!(omap_i2c_read_reg(omap, OMAP_I2C_SYSS_REG) & + SYSS_RESETDONE_MASK)) { + if (time_after(jiffies, timeout)) { + dev_warn(omap->dev, "timeout waiting " + "for controller reset\n"); + return -ETIMEDOUT; + } + msleep(1); + } + + /* SYSC register is cleared by the reset; rewrite it */ + omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, sysc); + + if (omap->rev > OMAP_I2C_REV_ON_3430_3530) { + /* Schedule I2C-bus monitoring on the next transfer */ + omap->bb_valid = 0; + } + } + + return 0; +} + +static int omap_i2c_init(struct omap_i2c_dev *omap) +{ + 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; + int error; + + if (omap->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. + */ + omap->westate = OMAP_I2C_WE_ALL; + } + + if (omap->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(omap->dev, "fck"); + if (IS_ERR(fclk)) { + error = PTR_ERR(fclk); + dev_err(omap->dev, "could not get fck: %i\n", error); + + return error; + } + + 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 (!(omap->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 (omap->speed > 400 || + omap->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK) + internal_clk = 19200; + else if (omap->speed > 100) + internal_clk = 9600; + else + internal_clk = 4000; + fclk = clk_get(omap->dev, "fck"); + if (IS_ERR(fclk)) { + error = PTR_ERR(fclk); + dev_err(omap->dev, "could not get fck: %i\n", error); + + return error; + } + 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 (omap->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 / omap->speed; + hsscll = scl - (scl / 3) - 7; + hssclh = (scl / 3) - 5; + } else if (omap->speed > 100) { + unsigned long scl; + + /* Fast mode */ + scl = internal_clk / omap->speed; + fsscll = scl - (scl / 3) - 7; + fssclh = (scl / 3) - 5; + } else { + /* Standard mode */ + fsscll = internal_clk / (omap->speed * 2) - 7; + fssclh = internal_clk / (omap->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 / (omap->speed * 2) - 7 + psc; + sclh = fclk_rate / (omap->speed * 2) - 7 + psc; + } + + omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | + OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | + OMAP_I2C_IE_AL) | ((omap->fifo_size) ? + (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0); + + omap->pscstate = psc; + omap->scllstate = scll; + omap->sclhstate = sclh; + + if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) { + /* Not implemented */ + omap->bb_valid = 1; + } + + __omap_i2c_init(omap); + + return 0; +} + +/* + * Try bus recovery, but only if SDA is actually low. + */ +static int omap_i2c_recover_bus(struct omap_i2c_dev *omap) +{ + u16 systest; + + systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG); + if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) && + (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) + return 0; /* bus seems to already be fine */ + if (!(systest & OMAP_I2C_SYSTEST_SCL_I_FUNC)) + return -EBUSY; /* recovery would not fix SCL */ + return i2c_recover_bus(&omap->adapter); +} + +/* + * Waiting on Bus Busy + */ +static int omap_i2c_wait_for_bb(struct omap_i2c_dev *omap) +{ + unsigned long timeout; + + timeout = jiffies + OMAP_I2C_TIMEOUT; + while (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) { + if (time_after(jiffies, timeout)) + return omap_i2c_recover_bus(omap); + msleep(1); + } + + return 0; +} + +/* + * Wait while BB-bit doesn't reflect the I2C bus state + * + * In a multimaster environment, after IP software reset, BB-bit value doesn't + * correspond to the current bus state. It may happen what BB-bit will be 0, + * while the bus is busy due to another I2C master activity. + * Here are BB-bit values after reset: + * SDA SCL BB NOTES + * 0 0 0 1, 2 + * 1 0 0 1, 2 + * 0 1 1 + * 1 1 0 3 + * Later, if IP detect SDA=0 and SCL=1 (ACK) or SDA 1->0 while SCL=1 (START) + * combinations on the bus, it set BB-bit to 1. + * If IP detect SDA 0->1 while SCL=1 (STOP) combination on the bus, + * it set BB-bit to 0 and BF to 1. + * BB and BF bits correctly tracks the bus state while IP is suspended + * BB bit became valid on the next FCLK clock after CON_EN bit set + * + * NOTES: + * 1. Any transfer started when BB=0 and bus is busy wouldn't be + * completed by IP and results in controller timeout. + * 2. Any transfer started when BB=0 and SCL=0 results in IP + * starting to drive SDA low. In that case IP corrupt data + * on the bus. + * 3. Any transfer started in the middle of another master's transfer + * results in unpredictable results and data corruption + */ +static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *omap) +{ + unsigned long bus_free_timeout = 0; + unsigned long timeout; + int bus_free = 0; + u16 stat, systest; + + if (omap->bb_valid) + return 0; + + timeout = jiffies + OMAP_I2C_TIMEOUT; + while (1) { + stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); + /* + * We will see BB or BF event in a case IP had detected any + * activity on the I2C bus. Now IP correctly tracks the bus + * state. BB-bit value is valid. + */ + if (stat & (OMAP_I2C_STAT_BB | OMAP_I2C_STAT_BF)) + break; + + /* + * Otherwise, we must look signals on the bus to make + * the right decision. + */ + systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG); + if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) && + (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) { + if (!bus_free) { + bus_free_timeout = jiffies + + OMAP_I2C_BUS_FREE_TIMEOUT; + bus_free = 1; + } + + /* + * SDA and SCL lines was high for 10 ms without bus + * activity detected. The bus is free. Consider + * BB-bit value is valid. + */ + if (time_after(jiffies, bus_free_timeout)) + break; + } else { + bus_free = 0; + } + + if (time_after(jiffies, timeout)) { + /* + * SDA or SCL were low for the entire timeout without + * any activity detected. Most likely, a slave is + * locking up the bus with no master driving the clock. + */ + dev_warn(omap->dev, "timeout waiting for bus ready\n"); + return omap_i2c_recover_bus(omap); + } + + msleep(1); + } + + omap->bb_valid = 1; + return 0; +} + +static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx) +{ + u16 buf; + + if (omap->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. + */ + + omap->threshold = clamp(size, (u8) 1, omap->fifo_size); + + buf = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG); + + if (is_rx) { + /* Clear RX Threshold */ + buf &= ~(0x3f << 8); + buf |= ((omap->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR; + } else { + /* Clear TX Threshold */ + buf &= ~0x3f; + buf |= (omap->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR; + } + + omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, buf); + + if (omap->rev < OMAP_I2C_REV_ON_3630) + omap->b_hw = 1; /* Enable hardware fixes */ + + /* calculate wakeup latency constraint for MPU */ + if (omap->set_mpu_wkup_lat != NULL) + omap->latency = (1000000 * omap->threshold) / + (1000 * omap->speed / 8); +} + +static void omap_i2c_wait(struct omap_i2c_dev *omap) +{ + u16 stat; + u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); + int count = 0; + + do { + stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); + count++; + } while (!(stat & mask) && count < 5); +} + +/* + * Low level master read/write transaction. + */ +static int omap_i2c_xfer_msg(struct i2c_adapter *adap, + struct i2c_msg *msg, int stop, bool polling) +{ + struct omap_i2c_dev *omap = i2c_get_adapdata(adap); + unsigned long timeout; + u16 w; + int ret; + + dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", + msg->addr, msg->len, msg->flags, stop); + + omap->receiver = !!(msg->flags & I2C_M_RD); + omap_i2c_resize_fifo(omap, msg->len, omap->receiver); + + omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr); + + /* REVISIT: Could the STB bit of I2C_CON be used with probing? */ + omap->buf = msg->buf; + omap->buf_len = msg->len; + + /* make sure writes to omap->buf_len are ordered */ + barrier(); + + omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len); + + /* Clear the FIFO Buffers */ + w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG); + w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR; + omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w); + + if (!polling) + reinit_completion(&omap->cmd_complete); + omap->cmd_err = 0; + + w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; + + /* High speed configuration */ + if (omap->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 (!omap->b_hw && stop) + w |= OMAP_I2C_CON_STP; + /* + * NOTE: STAT_BB bit could became 1 here if another master occupy + * the bus. IP successfully complete transfer when the bus will be + * free again (BB reset to 0). + */ + omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w); + + /* + * Don't write stt and stp together on some hardware. + */ + if (omap->b_hw && stop) { + unsigned long delay = jiffies + OMAP_I2C_TIMEOUT; + u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); + while (con & OMAP_I2C_CON_STT) { + con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); + + /* Let the user know if i2c is in a bad state */ + if (time_after(jiffies, delay)) { + dev_err(omap->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(omap, 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. + */ + if (!polling) { + timeout = wait_for_completion_timeout(&omap->cmd_complete, + OMAP_I2C_TIMEOUT); + } else { + do { + omap_i2c_wait(omap); + ret = omap_i2c_xfer_data(omap); + } while (ret == -EAGAIN); + + timeout = !ret; + } + + if (timeout == 0) { + dev_err(omap->dev, "controller timed out\n"); + omap_i2c_reset(omap); + __omap_i2c_init(omap); + return -ETIMEDOUT; + } + + if (likely(!omap->cmd_err)) + return 0; + + /* We have an error */ + if (omap->cmd_err & (OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) { + omap_i2c_reset(omap); + __omap_i2c_init(omap); + return -EIO; + } + + if (omap->cmd_err & OMAP_I2C_STAT_AL) + return -EAGAIN; + + if (omap->cmd_err & OMAP_I2C_STAT_NACK) { + if (msg->flags & I2C_M_IGNORE_NAK) + return 0; + + w = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); + w |= OMAP_I2C_CON_STP; + omap_i2c_write_reg(omap, 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_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num, + bool polling) +{ + struct omap_i2c_dev *omap = i2c_get_adapdata(adap); + int i; + int r; + + r = pm_runtime_get_sync(omap->dev); + if (r < 0) + goto out; + + r = omap_i2c_wait_for_bb_valid(omap); + if (r < 0) + goto out; + + r = omap_i2c_wait_for_bb(omap); + if (r < 0) + goto out; + + if (omap->set_mpu_wkup_lat != NULL) + omap->set_mpu_wkup_lat(omap->dev, omap->latency); + + for (i = 0; i < num; i++) { + r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)), + polling); + if (r != 0) + break; + } + + if (r == 0) + r = num; + + omap_i2c_wait_for_bb(omap); + + if (omap->set_mpu_wkup_lat != NULL) + omap->set_mpu_wkup_lat(omap->dev, -1); + +out: + pm_runtime_mark_last_busy(omap->dev); + pm_runtime_put_autosuspend(omap->dev); + return r; +} + +static int +omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + return omap_i2c_xfer_common(adap, msgs, num, false); +} + +static int +omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + return omap_i2c_xfer_common(adap, msgs, num, true); +} + +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 *omap, u16 err) +{ + omap->cmd_err |= err; + complete(&omap->cmd_complete); +} + +static inline void +omap_i2c_ack_stat(struct omap_i2c_dev *omap, u16 stat) +{ + omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, stat); +} + +static inline void i2c_omap_errata_i207(struct omap_i2c_dev *omap, 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(omap, OMAP_I2C_STAT_RDR); + + /* Step 2: */ + if (!(omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) + & OMAP_I2C_STAT_BB)) { + + /* Step 3: */ + if (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) + & OMAP_I2C_STAT_RDR) { + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); + dev_dbg(omap->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 *omap = dev_id; + u16 iv, w; + + if (pm_runtime_suspended(omap->dev)) + return IRQ_NONE; + + iv = omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); + switch (iv) { + case 0x00: /* None */ + break; + case 0x01: /* Arbitration lost */ + dev_err(omap->dev, "Arbitration lost\n"); + omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_AL); + break; + case 0x02: /* No acknowledgement */ + omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_NACK); + omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP); + break; + case 0x03: /* Register access ready */ + omap_i2c_complete_cmd(omap, 0); + break; + case 0x04: /* Receive data ready */ + if (omap->buf_len) { + w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG); + *omap->buf++ = w; + omap->buf_len--; + if (omap->buf_len) { + *omap->buf++ = w >> 8; + omap->buf_len--; + } + } else + dev_err(omap->dev, "RRDY IRQ while no data requested\n"); + break; + case 0x05: /* Transmit data ready */ + if (omap->buf_len) { + w = *omap->buf++; + omap->buf_len--; + if (omap->buf_len) { + w |= *omap->buf++ << 8; + omap->buf_len--; + } + omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w); + } else + dev_err(omap->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 *omap) +{ + unsigned long timeout = 10000; + u16 stat; + + do { + stat = omap_i2c_read_reg(omap, 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(omap, (OMAP_I2C_STAT_XRDY | + OMAP_I2C_STAT_XDR)); + if (stat & OMAP_I2C_STAT_NACK) { + omap->cmd_err |= OMAP_I2C_STAT_NACK; + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK); + } + + if (stat & OMAP_I2C_STAT_AL) { + dev_err(omap->dev, "Arbitration lost\n"); + omap->cmd_err |= OMAP_I2C_STAT_AL; + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL); + } + + return -EIO; + } + + cpu_relax(); + } while (--timeout); + + if (!timeout) { + dev_err(omap->dev, "timeout waiting on XUDF bit\n"); + return 0; + } + + return 0; +} + +static void omap_i2c_receive_data(struct omap_i2c_dev *omap, u8 num_bytes, + bool is_rdr) +{ + u16 w; + + while (num_bytes--) { + w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG); + *omap->buf++ = w; + omap->buf_len--; + + /* + * Data reg in 2430, omap3 and + * omap4 is 8 bit wide + */ + if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { + *omap->buf++ = w >> 8; + omap->buf_len--; + } + } +} + +static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes, + bool is_xdr) +{ + u16 w; + + while (num_bytes--) { + w = *omap->buf++; + omap->buf_len--; + + /* + * Data reg in 2430, omap3 and + * omap4 is 8 bit wide + */ + if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { + w |= *omap->buf++ << 8; + omap->buf_len--; + } + + if (omap->errata & I2C_OMAP_ERRATA_I462) { + int ret; + + ret = errata_omap3_i462(omap); + if (ret < 0) + return ret; + } + + omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w); + } + + return 0; +} + +static irqreturn_t +omap_i2c_isr(int irq, void *dev_id) +{ + struct omap_i2c_dev *omap = dev_id; + irqreturn_t ret = IRQ_HANDLED; + u16 mask; + u16 stat; + + stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); + mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG) & ~OMAP_I2C_STAT_NACK; + + if (stat & mask) + ret = IRQ_WAKE_THREAD; + + return ret; +} + +static int omap_i2c_xfer_data(struct omap_i2c_dev *omap) +{ + u16 bits; + u16 stat; + int err = 0, count = 0; + + do { + bits = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); + stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); + stat &= bits; + + /* If we're in receiver mode, ignore XDR/XRDY */ + if (omap->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 */ + err = -EAGAIN; + break; + } + + dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat); + if (count++ == 100) { + dev_warn(omap->dev, "Too much work in one IRQ\n"); + break; + } + + if (stat & OMAP_I2C_STAT_NACK) { + err |= OMAP_I2C_STAT_NACK; + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK); + } + + if (stat & OMAP_I2C_STAT_AL) { + dev_err(omap->dev, "Arbitration lost\n"); + err |= OMAP_I2C_STAT_AL; + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL); + } + + /* + * ProDB0017052: Clear ARDY bit twice + */ + if (stat & OMAP_I2C_STAT_ARDY) + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ARDY); + + if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | + OMAP_I2C_STAT_AL)) { + omap_i2c_ack_stat(omap, (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 (omap->fifo_size) + num_bytes = omap->buf_len; + + if (omap->errata & I2C_OMAP_ERRATA_I207) { + i2c_omap_errata_i207(omap, stat); + num_bytes = (omap_i2c_read_reg(omap, + OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F; + } + + omap_i2c_receive_data(omap, num_bytes, true); + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); + continue; + } + + if (stat & OMAP_I2C_STAT_RRDY) { + u8 num_bytes = 1; + + if (omap->threshold) + num_bytes = omap->threshold; + + omap_i2c_receive_data(omap, num_bytes, false); + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RRDY); + continue; + } + + if (stat & OMAP_I2C_STAT_XDR) { + u8 num_bytes = 1; + int ret; + + if (omap->fifo_size) + num_bytes = omap->buf_len; + + ret = omap_i2c_transmit_data(omap, num_bytes, true); + if (ret < 0) + break; + + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XDR); + continue; + } + + if (stat & OMAP_I2C_STAT_XRDY) { + u8 num_bytes = 1; + int ret; + + if (omap->threshold) + num_bytes = omap->threshold; + + ret = omap_i2c_transmit_data(omap, num_bytes, false); + if (ret < 0) + break; + + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XRDY); + continue; + } + + if (stat & OMAP_I2C_STAT_ROVR) { + dev_err(omap->dev, "Receive overrun\n"); + err |= OMAP_I2C_STAT_ROVR; + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ROVR); + break; + } + + if (stat & OMAP_I2C_STAT_XUDF) { + dev_err(omap->dev, "Transmit underflow\n"); + err |= OMAP_I2C_STAT_XUDF; + omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XUDF); + break; + } + } while (stat); + + return err; +} + +static irqreturn_t +omap_i2c_isr_thread(int this_irq, void *dev_id) +{ + int ret; + struct omap_i2c_dev *omap = dev_id; + + ret = omap_i2c_xfer_data(omap); + if (ret != -EAGAIN) + omap_i2c_complete_cmd(omap, ret); + + return IRQ_HANDLED; +} + +static const struct i2c_algorithm omap_i2c_algo = { + .master_xfer = omap_i2c_xfer_irq, + .master_xfer_atomic = omap_i2c_xfer_polling, + .functionality = omap_i2c_func, +}; + +static const struct i2c_adapter_quirks omap_i2c_quirks = { + .flags = I2C_AQ_NO_ZERO_LEN, +}; + +#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_get_scl(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + + return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC; +} + +static int omap_i2c_get_sda(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + + return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC; +} + +static void omap_i2c_set_scl(struct i2c_adapter *adap, int val) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + if (val) + reg |= OMAP_I2C_SYSTEST_SCL_O; + else + reg &= ~OMAP_I2C_SYSTEST_SCL_O; + omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); +} + +static void omap_i2c_prepare_recovery(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + /* enable test mode */ + reg |= OMAP_I2C_SYSTEST_ST_EN; + /* select SDA/SCL IO mode */ + reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT; + /* set SCL to high-impedance state (reset value is 0) */ + reg |= OMAP_I2C_SYSTEST_SCL_O; + /* set SDA to high-impedance state (reset value is 0) */ + reg |= OMAP_I2C_SYSTEST_SDA_O; + omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); +} + +static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap) +{ + struct omap_i2c_dev *dev = i2c_get_adapdata(adap); + u32 reg; + + reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); + /* restore reset values */ + reg &= ~OMAP_I2C_SYSTEST_ST_EN; + reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK; + reg &= ~OMAP_I2C_SYSTEST_SCL_O; + reg &= ~OMAP_I2C_SYSTEST_SDA_O; + omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); +} + +static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = { + .get_scl = omap_i2c_get_scl, + .get_sda = omap_i2c_get_sda, + .set_scl = omap_i2c_set_scl, + .prepare_recovery = omap_i2c_prepare_recovery, + .unprepare_recovery = omap_i2c_unprepare_recovery, + .recover_bus = i2c_generic_scl_recovery, +}; + +static int +omap_i2c_probe(struct platform_device *pdev) +{ + struct omap_i2c_dev *omap; + struct i2c_adapter *adap; + 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) + return irq; + + omap = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL); + if (!omap) + return -ENOMEM; + + omap->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(omap->base)) + return PTR_ERR(omap->base); + + match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev); + if (match) { + u32 freq = I2C_MAX_STANDARD_MODE_FREQ; + + pdata = match->data; + omap->flags = pdata->flags; + + of_property_read_u32(node, "clock-frequency", &freq); + /* convert DT freq value in Hz into kHz for speed */ + omap->speed = freq / 1000; + } else if (pdata != NULL) { + omap->speed = pdata->clkrate; + omap->flags = pdata->flags; + omap->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat; + } + + omap->dev = &pdev->dev; + omap->irq = irq; + + platform_set_drvdata(pdev, omap); + init_completion(&omap->cmd_complete); + + omap->reg_shift = (omap->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3; + + pm_runtime_enable(omap->dev); + pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT); + pm_runtime_use_autosuspend(omap->dev); + + r = pm_runtime_resume_and_get(omap->dev); + if (r < 0) + goto err_disable_pm; + + /* + * 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(omap->base + 0x04); + + omap->scheme = OMAP_I2C_SCHEME(rev); + switch (omap->scheme) { + case OMAP_I2C_SCHEME_0: + omap->regs = (u8 *)reg_map_ip_v1; + omap->rev = omap_i2c_read_reg(omap, OMAP_I2C_REV_REG); + minor = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev); + major = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev); + break; + case OMAP_I2C_SCHEME_1: + default: + omap->regs = (u8 *)reg_map_ip_v2; + rev = (rev << 16) | + omap_i2c_read_reg(omap, OMAP_I2C_IP_V2_REVNB_LO); + minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev); + major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev); + omap->rev = rev; + } + + omap->errata = 0; + + if (omap->rev >= OMAP_I2C_REV_ON_2430 && + omap->rev < OMAP_I2C_REV_ON_4430_PLUS) + omap->errata |= I2C_OMAP_ERRATA_I207; + + if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) + omap->errata |= I2C_OMAP_ERRATA_I462; + + if (!(omap->flags & OMAP_I2C_FLAG_NO_FIFO)) { + u16 s; + + /* Set up the fifo size - Get total size */ + s = (omap_i2c_read_reg(omap, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3; + omap->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. + */ + + omap->fifo_size = (omap->fifo_size / 2); + + if (omap->rev < OMAP_I2C_REV_ON_3630) + omap->b_hw = 1; /* Enable hardware fixes */ + + /* calculate wakeup latency constraint for MPU */ + if (omap->set_mpu_wkup_lat != NULL) + omap->latency = (1000000 * omap->fifo_size) / + (1000 * omap->speed / 8); + } + + /* reset ASAP, clearing any IRQs */ + omap_i2c_init(omap); + + if (omap->rev < OMAP_I2C_OMAP1_REV_2) + r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr, + IRQF_NO_SUSPEND, pdev->name, omap); + else + r = devm_request_threaded_irq(&pdev->dev, omap->irq, + omap_i2c_isr, omap_i2c_isr_thread, + IRQF_NO_SUSPEND | IRQF_ONESHOT, + pdev->name, omap); + + if (r) { + dev_err(omap->dev, "failure requesting irq %i\n", omap->irq); + goto err_unuse_clocks; + } + + adap = &omap->adapter; + i2c_set_adapdata(adap, omap); + adap->owner = THIS_MODULE; + adap->class = I2C_CLASS_DEPRECATED; + strscpy(adap->name, "OMAP I2C adapter", sizeof(adap->name)); + adap->algo = &omap_i2c_algo; + adap->quirks = &omap_i2c_quirks; + adap->dev.parent = &pdev->dev; + adap->dev.of_node = pdev->dev.of_node; + adap->bus_recovery_info = &omap_i2c_bus_recovery_info; + + /* i2c device drivers may be active on return from add_adapter() */ + adap->nr = pdev->id; + r = i2c_add_numbered_adapter(adap); + if (r) + goto err_unuse_clocks; + + dev_info(omap->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr, + major, minor, omap->speed); + + pm_runtime_mark_last_busy(omap->dev); + pm_runtime_put_autosuspend(omap->dev); + + return 0; + +err_unuse_clocks: + omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); + pm_runtime_dont_use_autosuspend(omap->dev); + pm_runtime_put_sync(omap->dev); +err_disable_pm: + pm_runtime_disable(&pdev->dev); + + return r; +} + +static int omap_i2c_remove(struct platform_device *pdev) +{ + struct omap_i2c_dev *omap = platform_get_drvdata(pdev); + int ret; + + i2c_del_adapter(&omap->adapter); + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) + return ret; + + omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); + pm_runtime_dont_use_autosuspend(&pdev->dev); + pm_runtime_put_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); + return 0; +} + +static int __maybe_unused omap_i2c_runtime_suspend(struct device *dev) +{ + struct omap_i2c_dev *omap = dev_get_drvdata(dev); + + omap->iestate = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); + + if (omap->scheme == OMAP_I2C_SCHEME_0) + omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, 0); + else + omap_i2c_write_reg(omap, OMAP_I2C_IP_V2_IRQENABLE_CLR, + OMAP_I2C_IP_V2_INTERRUPTS_MASK); + + if (omap->rev < OMAP_I2C_OMAP1_REV_2) { + omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); /* Read clears */ + } else { + omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, omap->iestate); + + /* Flush posted write */ + omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); + } + + pinctrl_pm_select_sleep_state(dev); + + return 0; +} + +static int __maybe_unused omap_i2c_runtime_resume(struct device *dev) +{ + struct omap_i2c_dev *omap = dev_get_drvdata(dev); + + pinctrl_pm_select_default_state(dev); + + if (!omap->regs) + return 0; + + __omap_i2c_init(omap); + + return 0; +} + +static const struct dev_pm_ops omap_i2c_pm_ops = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend, + omap_i2c_runtime_resume, NULL) +}; + +static struct platform_driver omap_i2c_driver = { + .probe = omap_i2c_probe, + .remove = omap_i2c_remove, + .driver = { + .name = "omap_i2c", + .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"); |