diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-davinci.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-davinci.c | 964 |
1 files changed, 964 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c new file mode 100644 index 0000000000..02b3b1160f --- /dev/null +++ b/drivers/i2c/busses/i2c-davinci.c @@ -0,0 +1,964 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * TI DAVINCI I2C adapter driver. + * + * Copyright (C) 2006 Texas Instruments. + * Copyright (C) 2007 MontaVista Software Inc. + * + * Updated by Vinod & Sudhakar Feb 2005 + * + * ---------------------------------------------------------------------------- + * + * ---------------------------------------------------------------------------- + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/clk.h> +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/cpufreq.h> +#include <linux/gpio/consumer.h> +#include <linux/of.h> +#include <linux/platform_data/i2c-davinci.h> +#include <linux/pm_runtime.h> + +/* ----- global defines ----------------------------------------------- */ + +#define DAVINCI_I2C_TIMEOUT (1*HZ) +#define DAVINCI_I2C_MAX_TRIES 2 +#define DAVINCI_I2C_OWN_ADDRESS 0x08 +#define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_SCD | \ + DAVINCI_I2C_IMR_ARDY | \ + DAVINCI_I2C_IMR_NACK | \ + DAVINCI_I2C_IMR_AL) + +#define DAVINCI_I2C_OAR_REG 0x00 +#define DAVINCI_I2C_IMR_REG 0x04 +#define DAVINCI_I2C_STR_REG 0x08 +#define DAVINCI_I2C_CLKL_REG 0x0c +#define DAVINCI_I2C_CLKH_REG 0x10 +#define DAVINCI_I2C_CNT_REG 0x14 +#define DAVINCI_I2C_DRR_REG 0x18 +#define DAVINCI_I2C_SAR_REG 0x1c +#define DAVINCI_I2C_DXR_REG 0x20 +#define DAVINCI_I2C_MDR_REG 0x24 +#define DAVINCI_I2C_IVR_REG 0x28 +#define DAVINCI_I2C_EMDR_REG 0x2c +#define DAVINCI_I2C_PSC_REG 0x30 +#define DAVINCI_I2C_FUNC_REG 0x48 +#define DAVINCI_I2C_DIR_REG 0x4c +#define DAVINCI_I2C_DIN_REG 0x50 +#define DAVINCI_I2C_DOUT_REG 0x54 +#define DAVINCI_I2C_DSET_REG 0x58 +#define DAVINCI_I2C_DCLR_REG 0x5c + +#define DAVINCI_I2C_IVR_AAS 0x07 +#define DAVINCI_I2C_IVR_SCD 0x06 +#define DAVINCI_I2C_IVR_XRDY 0x05 +#define DAVINCI_I2C_IVR_RDR 0x04 +#define DAVINCI_I2C_IVR_ARDY 0x03 +#define DAVINCI_I2C_IVR_NACK 0x02 +#define DAVINCI_I2C_IVR_AL 0x01 + +#define DAVINCI_I2C_STR_BB BIT(12) +#define DAVINCI_I2C_STR_RSFULL BIT(11) +#define DAVINCI_I2C_STR_SCD BIT(5) +#define DAVINCI_I2C_STR_ARDY BIT(2) +#define DAVINCI_I2C_STR_NACK BIT(1) +#define DAVINCI_I2C_STR_AL BIT(0) + +#define DAVINCI_I2C_MDR_NACK BIT(15) +#define DAVINCI_I2C_MDR_STT BIT(13) +#define DAVINCI_I2C_MDR_STP BIT(11) +#define DAVINCI_I2C_MDR_MST BIT(10) +#define DAVINCI_I2C_MDR_TRX BIT(9) +#define DAVINCI_I2C_MDR_XA BIT(8) +#define DAVINCI_I2C_MDR_RM BIT(7) +#define DAVINCI_I2C_MDR_IRS BIT(5) + +#define DAVINCI_I2C_IMR_AAS BIT(6) +#define DAVINCI_I2C_IMR_SCD BIT(5) +#define DAVINCI_I2C_IMR_XRDY BIT(4) +#define DAVINCI_I2C_IMR_RRDY BIT(3) +#define DAVINCI_I2C_IMR_ARDY BIT(2) +#define DAVINCI_I2C_IMR_NACK BIT(1) +#define DAVINCI_I2C_IMR_AL BIT(0) + +/* set SDA and SCL as GPIO */ +#define DAVINCI_I2C_FUNC_PFUNC0 BIT(0) + +/* set SCL as output when used as GPIO*/ +#define DAVINCI_I2C_DIR_PDIR0 BIT(0) +/* set SDA as output when used as GPIO*/ +#define DAVINCI_I2C_DIR_PDIR1 BIT(1) + +/* read SCL GPIO level */ +#define DAVINCI_I2C_DIN_PDIN0 BIT(0) +/* read SDA GPIO level */ +#define DAVINCI_I2C_DIN_PDIN1 BIT(1) + +/*set the SCL GPIO high */ +#define DAVINCI_I2C_DSET_PDSET0 BIT(0) +/*set the SDA GPIO high */ +#define DAVINCI_I2C_DSET_PDSET1 BIT(1) + +/* set the SCL GPIO low */ +#define DAVINCI_I2C_DCLR_PDCLR0 BIT(0) +/* set the SDA GPIO low */ +#define DAVINCI_I2C_DCLR_PDCLR1 BIT(1) + +/* timeout for pm runtime autosuspend */ +#define DAVINCI_I2C_PM_TIMEOUT 1000 /* ms */ + +struct davinci_i2c_dev { + struct device *dev; + void __iomem *base; + struct completion cmd_complete; + struct clk *clk; + int cmd_err; + u8 *buf; + size_t buf_len; + int irq; + int stop; + u8 terminate; + struct i2c_adapter adapter; +#ifdef CONFIG_CPU_FREQ + struct notifier_block freq_transition; +#endif + struct davinci_i2c_platform_data *pdata; +}; + +/* default platform data to use if not supplied in the platform_device */ +static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = { + .bus_freq = 100, + .bus_delay = 0, +}; + +static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev, + int reg, u16 val) +{ + writew_relaxed(val, i2c_dev->base + reg); +} + +static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) +{ + return readw_relaxed(i2c_dev->base + reg); +} + +static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, + int val) +{ + u16 w; + + w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG); + if (!val) /* put I2C into reset */ + w &= ~DAVINCI_I2C_MDR_IRS; + else /* take I2C out of reset */ + w |= DAVINCI_I2C_MDR_IRS; + + davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w); +} + +static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev) +{ + struct davinci_i2c_platform_data *pdata = dev->pdata; + u16 psc; + u32 clk; + u32 d; + u32 clkh; + u32 clkl; + u32 input_clock = clk_get_rate(dev->clk); + struct device_node *of_node = dev->dev->of_node; + + /* NOTE: I2C Clock divider programming info + * As per I2C specs the following formulas provide prescaler + * and low/high divider values + * input clk --> PSC Div -----------> ICCL/H Div --> output clock + * module clk + * + * output clk = module clk / (PSC + 1) [ (ICCL + d) + (ICCH + d) ] + * + * Thus, + * (ICCL + ICCH) = clk = (input clk / ((psc +1) * output clk)) - 2d; + * + * where if PSC == 0, d = 7, + * if PSC == 1, d = 6 + * if PSC > 1 , d = 5 + * + * Note: + * d is always 6 on Keystone I2C controller + */ + + /* + * Both Davinci and current Keystone User Guides recommend a value + * between 7MHz and 12MHz. In reality 7MHz module clock doesn't + * always produce enough margin between SDA and SCL transitions. + * Measurements show that the higher the module clock is, the + * bigger is the margin, providing more reliable communication. + * So we better target for 12MHz. + */ + psc = (input_clock / 12000000) - 1; + if ((input_clock / (psc + 1)) > 12000000) + psc++; /* better to run under spec than over */ + d = (psc >= 2) ? 5 : 7 - psc; + + if (of_node && of_device_is_compatible(of_node, "ti,keystone-i2c")) + d = 6; + + clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)); + /* Avoid driving the bus too fast because of rounding errors above */ + if (input_clock / (psc + 1) / clk > pdata->bus_freq * 1000) + clk++; + /* + * According to I2C-BUS Spec 2.1, in FAST-MODE LOW period should be at + * least 1.3uS, which is not the case with 50% duty cycle. Driving HIGH + * to LOW ratio as 1 to 2 is more safe. + */ + if (pdata->bus_freq > 100) + clkl = (clk << 1) / 3; + else + clkl = (clk >> 1); + /* + * It's not always possible to have 1 to 2 ratio when d=7, so fall back + * to minimal possible clkh in this case. + * + * Note: + * CLKH is not allowed to be 0, in this case I2C clock is not generated + * at all + */ + if (clk > clkl + d) { + clkh = clk - clkl - d; + clkl -= d; + } else { + clkh = 1; + clkl = clk - (d << 1); + } + + davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc); + davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh); + davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl); + + dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk); +} + +/* + * This function configures I2C and brings I2C out of reset. + * This function is called during I2C init function. This function + * also gets called if I2C encounters any errors. + */ +static int i2c_davinci_init(struct davinci_i2c_dev *dev) +{ + struct davinci_i2c_platform_data *pdata = dev->pdata; + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(dev, 0); + + /* compute clock dividers */ + i2c_davinci_calc_clk_dividers(dev); + + /* Respond at reserved "SMBus Host" slave address" (and zero); + * we seem to have no option to not respond... + */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, DAVINCI_I2C_OWN_ADDRESS); + + dev_dbg(dev->dev, "PSC = %d\n", + davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG)); + dev_dbg(dev->dev, "CLKL = %d\n", + davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG)); + dev_dbg(dev->dev, "CLKH = %d\n", + davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG)); + dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n", + pdata->bus_freq, pdata->bus_delay); + + + /* Take the I2C module out of reset: */ + davinci_i2c_reset_ctrl(dev, 1); + + /* Enable interrupts */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL); + + return 0; +} + +/* + * This routine does i2c bus recovery by using i2c_generic_scl_recovery + * which is provided by I2C Bus recovery infrastructure. + */ +static void davinci_i2c_prepare_recovery(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + + /* Disable interrupts */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, 0); + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(dev, 0); +} + +static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + + i2c_davinci_init(dev); +} + +static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = { + .recover_bus = i2c_generic_scl_recovery, + .prepare_recovery = davinci_i2c_prepare_recovery, + .unprepare_recovery = davinci_i2c_unprepare_recovery, +}; + +static void davinci_i2c_set_scl(struct i2c_adapter *adap, int val) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + + if (val) + davinci_i2c_write_reg(dev, DAVINCI_I2C_DSET_REG, + DAVINCI_I2C_DSET_PDSET0); + else + davinci_i2c_write_reg(dev, DAVINCI_I2C_DCLR_REG, + DAVINCI_I2C_DCLR_PDCLR0); +} + +static int davinci_i2c_get_scl(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + int val; + + /* read the state of SCL */ + val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG); + return val & DAVINCI_I2C_DIN_PDIN0; +} + +static int davinci_i2c_get_sda(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + int val; + + /* read the state of SDA */ + val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG); + return val & DAVINCI_I2C_DIN_PDIN1; +} + +static void davinci_i2c_scl_prepare_recovery(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + + davinci_i2c_prepare_recovery(adap); + + /* SCL output, SDA input */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_DIR_REG, DAVINCI_I2C_DIR_PDIR0); + + /* change to GPIO mode */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, + DAVINCI_I2C_FUNC_PFUNC0); +} + +static void davinci_i2c_scl_unprepare_recovery(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + + /* change back to I2C mode */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, 0); + + davinci_i2c_unprepare_recovery(adap); +} + +static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = { + .recover_bus = i2c_generic_scl_recovery, + .set_scl = davinci_i2c_set_scl, + .get_scl = davinci_i2c_get_scl, + .get_sda = davinci_i2c_get_sda, + .prepare_recovery = davinci_i2c_scl_prepare_recovery, + .unprepare_recovery = davinci_i2c_scl_unprepare_recovery, +}; + +/* + * Waiting for bus not busy + */ +static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev) +{ + unsigned long timeout = jiffies + dev->adapter.timeout; + + do { + if (!(davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB)) + return 0; + schedule_timeout_uninterruptible(1); + } while (time_before_eq(jiffies, timeout)); + + dev_warn(dev->dev, "timeout waiting for bus ready\n"); + i2c_recover_bus(&dev->adapter); + + /* + * if bus is still "busy" here, it's most probably a HW problem like + * short-circuit + */ + if (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB) + return -EIO; + + return 0; +} + +/* + * Low level master read/write transaction. This function is called + * from i2c_davinci_xfer. + */ +static int +i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + struct davinci_i2c_platform_data *pdata = dev->pdata; + u32 flag; + u16 w; + unsigned long time_left; + + if (msg->addr == DAVINCI_I2C_OWN_ADDRESS) { + dev_warn(dev->dev, "transfer to own address aborted\n"); + return -EADDRNOTAVAIL; + } + + /* Introduce a delay, required for some boards (e.g Davinci EVM) */ + if (pdata->bus_delay) + udelay(pdata->bus_delay); + + /* set the slave address */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr); + + dev->buf = msg->buf; + dev->buf_len = msg->len; + dev->stop = stop; + + davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); + + reinit_completion(&dev->cmd_complete); + dev->cmd_err = 0; + + /* Take I2C out of reset and configure it as master */ + flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST; + + /* if the slave address is ten bit address, enable XA bit */ + if (msg->flags & I2C_M_TEN) + flag |= DAVINCI_I2C_MDR_XA; + if (!(msg->flags & I2C_M_RD)) + flag |= DAVINCI_I2C_MDR_TRX; + if (msg->len == 0) + flag |= DAVINCI_I2C_MDR_RM; + + /* Enable receive or transmit interrupts */ + w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); + if (msg->flags & I2C_M_RD) + w |= DAVINCI_I2C_IMR_RRDY; + else + w |= DAVINCI_I2C_IMR_XRDY; + davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w); + + dev->terminate = 0; + + /* + * Write mode register first as needed for correct behaviour + * on OMAP-L138, but don't set STT yet to avoid a race with XRDY + * occurring before we have loaded DXR + */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); + + /* + * First byte should be set here, not after interrupt, + * because transmit-data-ready interrupt can come before + * NACK-interrupt during sending of previous message and + * ICDXR may have wrong data + * It also saves us one interrupt, slightly faster + */ + if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) { + davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++); + dev->buf_len--; + } + + /* Set STT to begin transmit now DXR is loaded */ + flag |= DAVINCI_I2C_MDR_STT; + if (stop && msg->len != 0) + flag |= DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); + + time_left = wait_for_completion_timeout(&dev->cmd_complete, + dev->adapter.timeout); + if (!time_left) { + dev_err(dev->dev, "controller timed out\n"); + i2c_recover_bus(adap); + dev->buf_len = 0; + return -ETIMEDOUT; + } + if (dev->buf_len) { + /* This should be 0 if all bytes were transferred + * or dev->cmd_err denotes an error. + */ + dev_err(dev->dev, "abnormal termination buf_len=%zu\n", + dev->buf_len); + dev->terminate = 1; + wmb(); + dev->buf_len = 0; + return -EREMOTEIO; + } + + /* no error */ + if (likely(!dev->cmd_err)) + return msg->len; + + /* We have an error */ + if (dev->cmd_err & DAVINCI_I2C_STR_AL) { + i2c_davinci_init(dev); + return -EIO; + } + + if (dev->cmd_err & DAVINCI_I2C_STR_NACK) { + if (msg->flags & I2C_M_IGNORE_NAK) + return msg->len; + w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + return -EREMOTEIO; + } + return -EIO; +} + +/* + * Prepare controller for a transaction and call i2c_davinci_xfer_msg + */ +static int +i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + int i; + int ret; + + dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); + + ret = pm_runtime_resume_and_get(dev->dev); + if (ret < 0) { + dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret); + return ret; + } + + ret = i2c_davinci_wait_bus_not_busy(dev); + if (ret < 0) { + dev_warn(dev->dev, "timeout waiting for bus ready\n"); + goto out; + } + + for (i = 0; i < num; i++) { + ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1))); + dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num, + ret); + if (ret < 0) + goto out; + } + + ret = num; + +out: + pm_runtime_mark_last_busy(dev->dev); + pm_runtime_put_autosuspend(dev->dev); + + return ret; +} + +static u32 i2c_davinci_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static void terminate_read(struct davinci_i2c_dev *dev) +{ + u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_NACK; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + + /* Throw away data */ + davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG); + if (!dev->terminate) + dev_err(dev->dev, "RDR IRQ while no data requested\n"); +} +static void terminate_write(struct davinci_i2c_dev *dev) +{ + u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w); + + if (!dev->terminate) + dev_dbg(dev->dev, "TDR IRQ while no data to send\n"); +} + +/* + * Interrupt service routine. This gets called whenever an I2C interrupt + * occurs. + */ +static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) +{ + struct davinci_i2c_dev *dev = dev_id; + u32 stat; + int count = 0; + u16 w; + + if (pm_runtime_suspended(dev->dev)) + return IRQ_NONE; + + while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) { + dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat); + if (count++ == 100) { + dev_warn(dev->dev, "Too much work in one IRQ\n"); + break; + } + + switch (stat) { + case DAVINCI_I2C_IVR_AL: + /* Arbitration lost, must retry */ + dev->cmd_err |= DAVINCI_I2C_STR_AL; + dev->buf_len = 0; + complete(&dev->cmd_complete); + break; + + case DAVINCI_I2C_IVR_NACK: + dev->cmd_err |= DAVINCI_I2C_STR_NACK; + dev->buf_len = 0; + complete(&dev->cmd_complete); + break; + + case DAVINCI_I2C_IVR_ARDY: + davinci_i2c_write_reg(dev, + DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY); + if (((dev->buf_len == 0) && (dev->stop != 0)) || + (dev->cmd_err & DAVINCI_I2C_STR_NACK)) { + w = davinci_i2c_read_reg(dev, + DAVINCI_I2C_MDR_REG); + w |= DAVINCI_I2C_MDR_STP; + davinci_i2c_write_reg(dev, + DAVINCI_I2C_MDR_REG, w); + } + complete(&dev->cmd_complete); + break; + + case DAVINCI_I2C_IVR_RDR: + if (dev->buf_len) { + *dev->buf++ = + davinci_i2c_read_reg(dev, + DAVINCI_I2C_DRR_REG); + dev->buf_len--; + if (dev->buf_len) + continue; + + davinci_i2c_write_reg(dev, + DAVINCI_I2C_STR_REG, + DAVINCI_I2C_IMR_RRDY); + } else { + /* signal can terminate transfer */ + terminate_read(dev); + } + break; + + case DAVINCI_I2C_IVR_XRDY: + if (dev->buf_len) { + davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, + *dev->buf++); + dev->buf_len--; + if (dev->buf_len) + continue; + + w = davinci_i2c_read_reg(dev, + DAVINCI_I2C_IMR_REG); + w &= ~DAVINCI_I2C_IMR_XRDY; + davinci_i2c_write_reg(dev, + DAVINCI_I2C_IMR_REG, + w); + } else { + /* signal can terminate transfer */ + terminate_write(dev); + } + break; + + case DAVINCI_I2C_IVR_SCD: + davinci_i2c_write_reg(dev, + DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD); + complete(&dev->cmd_complete); + break; + + case DAVINCI_I2C_IVR_AAS: + dev_dbg(dev->dev, "Address as slave interrupt\n"); + break; + + default: + dev_warn(dev->dev, "Unrecognized irq stat %d\n", stat); + break; + } + } + + return count ? IRQ_HANDLED : IRQ_NONE; +} + +#ifdef CONFIG_CPU_FREQ +static int i2c_davinci_cpufreq_transition(struct notifier_block *nb, + unsigned long val, void *data) +{ + struct davinci_i2c_dev *dev; + + dev = container_of(nb, struct davinci_i2c_dev, freq_transition); + + i2c_lock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER); + if (val == CPUFREQ_PRECHANGE) { + davinci_i2c_reset_ctrl(dev, 0); + } else if (val == CPUFREQ_POSTCHANGE) { + i2c_davinci_calc_clk_dividers(dev); + davinci_i2c_reset_ctrl(dev, 1); + } + i2c_unlock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER); + + return 0; +} + +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition; + + return cpufreq_register_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ + cpufreq_unregister_notifier(&dev->freq_transition, + CPUFREQ_TRANSITION_NOTIFIER); +} +#else +static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev) +{ + return 0; +} + +static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev) +{ +} +#endif + +static const struct i2c_algorithm i2c_davinci_algo = { + .master_xfer = i2c_davinci_xfer, + .functionality = i2c_davinci_func, +}; + +static const struct of_device_id davinci_i2c_of_match[] = { + {.compatible = "ti,davinci-i2c", }, + {.compatible = "ti,keystone-i2c", }, + {}, +}; +MODULE_DEVICE_TABLE(of, davinci_i2c_of_match); + +static int davinci_i2c_probe(struct platform_device *pdev) +{ + struct davinci_i2c_dev *dev; + struct i2c_adapter *adap; + struct i2c_bus_recovery_info *rinfo; + int r, irq; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + init_completion(&dev->cmd_complete); + + dev->dev = &pdev->dev; + dev->irq = irq; + dev->pdata = dev_get_platdata(&pdev->dev); + platform_set_drvdata(pdev, dev); + + if (!dev->pdata && pdev->dev.of_node) { + u32 prop; + + dev->pdata = devm_kzalloc(&pdev->dev, + sizeof(struct davinci_i2c_platform_data), GFP_KERNEL); + if (!dev->pdata) + return -ENOMEM; + + memcpy(dev->pdata, &davinci_i2c_platform_data_default, + sizeof(struct davinci_i2c_platform_data)); + if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &prop)) + dev->pdata->bus_freq = prop / 1000; + + dev->pdata->has_pfunc = + of_property_read_bool(pdev->dev.of_node, + "ti,has-pfunc"); + } else if (!dev->pdata) { + dev->pdata = &davinci_i2c_platform_data_default; + } + + dev->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + + dev->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(dev->base)) { + return PTR_ERR(dev->base); + } + + pm_runtime_set_autosuspend_delay(dev->dev, + DAVINCI_I2C_PM_TIMEOUT); + pm_runtime_use_autosuspend(dev->dev); + + pm_runtime_enable(dev->dev); + + r = pm_runtime_resume_and_get(dev->dev); + if (r < 0) { + dev_err(dev->dev, "failed to runtime_get device: %d\n", r); + goto err_pm; + } + + i2c_davinci_init(dev); + + r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0, + pdev->name, dev); + if (r) { + dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); + goto err_unuse_clocks; + } + + r = i2c_davinci_cpufreq_register(dev); + if (r) { + dev_err(&pdev->dev, "failed to register cpufreq\n"); + goto err_unuse_clocks; + } + + adap = &dev->adapter; + i2c_set_adapdata(adap, dev); + adap->owner = THIS_MODULE; + adap->class = I2C_CLASS_DEPRECATED; + strscpy(adap->name, "DaVinci I2C adapter", sizeof(adap->name)); + adap->algo = &i2c_davinci_algo; + adap->dev.parent = &pdev->dev; + adap->timeout = DAVINCI_I2C_TIMEOUT; + adap->dev.of_node = pdev->dev.of_node; + + if (dev->pdata->has_pfunc) + adap->bus_recovery_info = &davinci_i2c_scl_recovery_info; + else if (dev->pdata->gpio_recovery) { + rinfo = &davinci_i2c_gpio_recovery_info; + adap->bus_recovery_info = rinfo; + rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", + GPIOD_OUT_HIGH_OPEN_DRAIN); + if (IS_ERR(rinfo->scl_gpiod)) { + r = PTR_ERR(rinfo->scl_gpiod); + goto err_unuse_clocks; + } + rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN); + if (IS_ERR(rinfo->sda_gpiod)) { + r = PTR_ERR(rinfo->sda_gpiod); + goto err_unuse_clocks; + } + } + + adap->nr = pdev->id; + r = i2c_add_numbered_adapter(adap); + if (r) + goto err_unuse_clocks; + + pm_runtime_mark_last_busy(dev->dev); + pm_runtime_put_autosuspend(dev->dev); + + return 0; + +err_unuse_clocks: + pm_runtime_dont_use_autosuspend(dev->dev); + pm_runtime_put_sync(dev->dev); +err_pm: + pm_runtime_disable(dev->dev); + + return r; +} + +static void davinci_i2c_remove(struct platform_device *pdev) +{ + struct davinci_i2c_dev *dev = platform_get_drvdata(pdev); + int ret; + + i2c_davinci_cpufreq_deregister(dev); + + i2c_del_adapter(&dev->adapter); + + ret = pm_runtime_get_sync(&pdev->dev); + if (ret < 0) + dev_err(&pdev->dev, "Failed to resume device\n"); + else + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0); + + pm_runtime_dont_use_autosuspend(dev->dev); + pm_runtime_put_sync(dev->dev); + pm_runtime_disable(dev->dev); +} + +static int davinci_i2c_suspend(struct device *dev) +{ + struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev); + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(i2c_dev, 0); + + return 0; +} + +static int davinci_i2c_resume(struct device *dev) +{ + struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev); + + /* take I2C out of reset */ + davinci_i2c_reset_ctrl(i2c_dev, 1); + + return 0; +} + +static const struct dev_pm_ops davinci_i2c_pm = { + .suspend = davinci_i2c_suspend, + .resume = davinci_i2c_resume, + NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) +}; + +static const struct platform_device_id davinci_i2c_driver_ids[] = { + { .name = "i2c_davinci", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, davinci_i2c_driver_ids); + +static struct platform_driver davinci_i2c_driver = { + .probe = davinci_i2c_probe, + .remove_new = davinci_i2c_remove, + .id_table = davinci_i2c_driver_ids, + .driver = { + .name = "i2c_davinci", + .pm = pm_sleep_ptr(&davinci_i2c_pm), + .of_match_table = davinci_i2c_of_match, + }, +}; + +/* I2C may be needed to bring up other drivers */ +static int __init davinci_i2c_init_driver(void) +{ + return platform_driver_register(&davinci_i2c_driver); +} +subsys_initcall(davinci_i2c_init_driver); + +static void __exit davinci_i2c_exit_driver(void) +{ + platform_driver_unregister(&davinci_i2c_driver); +} +module_exit(davinci_i2c_exit_driver); + +MODULE_AUTHOR("Texas Instruments India"); +MODULE_DESCRIPTION("TI DaVinci I2C bus adapter"); +MODULE_LICENSE("GPL"); |