From: Robert Hancock <robert.hancock@xxxxxxxxxx> Hook up the standard GPIO/pinctrl-based recovery support.. In the discurssion https://patchwork.ozlabs.org/project/linux-i2c/patch/20211129090116.16628-1-shubhrajyoti.datta@xxxxxxxxxx/ recovery should be done at the beginning of the transaction. Here we are doing the recovery at the beginning on a timeout. Signed-off-by: Robert Hancock <robert.hancock@xxxxxxxxxx> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxx> --- v2: Updated the busbusy check on a timeout drivers/i2c/busses/i2c-cadence.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c index b4c1ad19cdae..cf15eca1f9e4 100644 --- a/drivers/i2c/busses/i2c-cadence.c +++ b/drivers/i2c/busses/i2c-cadence.c @@ -10,6 +10,7 @@ #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/of.h> @@ -125,6 +126,8 @@ #define CDNS_I2C_DIVB_MAX 64 #define CDNS_I2C_TIMEOUT_MAX 0xFF +#define CDNS_I2C_POLL_US 100000 +#define CDNS_I2C_TIMEOUT_US 500000 #define CDNS_I2C_BROKEN_HOLD_BIT BIT(0) @@ -179,6 +182,7 @@ enum cdns_i2c_slave_state { * @clk_rate_change_nb: Notifier block for clock rate changes * @quirks: flag for broken hold bit usage in r1p10 * @ctrl_reg: Cached value of the control register. + * @rinfo: Structure holding recovery information. * @ctrl_reg_diva_divb: value of fields DIV_A and DIV_B from CR register * @slave: Registered slave instance. * @dev_mode: I2C operating role(master/slave). @@ -204,6 +208,7 @@ struct cdns_i2c { struct notifier_block clk_rate_change_nb; u32 quirks; u32 ctrl_reg; + struct i2c_bus_recovery_info rinfo; #if IS_ENABLED(CONFIG_I2C_SLAVE) u16 ctrl_reg_diva_divb; struct i2c_client *slave; @@ -796,6 +801,7 @@ static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg, /* Wait for the signal of completion */ time_left = wait_for_completion_timeout(&id->xfer_done, msg_timeout); if (time_left == 0) { + i2c_recover_bus(adap); cdns_i2c_master_reset(adap); dev_err(id->adap.dev.parent, "timeout waiting on completion\n"); @@ -852,8 +858,12 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, #endif /* Check if the bus is free */ - if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) { + ret = readl_poll_timeout(id->membase + CDNS_I2C_SR_OFFSET, reg, + !(reg & CDNS_I2C_SR_BA), + CDNS_I2C_POLL_US, CDNS_I2C_TIMEOUT_US); + if (ret) { ret = -EAGAIN; + i2c_recover_bus(adap); goto out; } @@ -1278,6 +1288,7 @@ static int cdns_i2c_probe(struct platform_device *pdev) id->adap.retries = 3; /* Default retry value. */ id->adap.algo_data = id; id->adap.dev.parent = &pdev->dev; + id->adap.bus_recovery_info = &id->rinfo; init_completion(&id->xfer_done); snprintf(id->adap.name, sizeof(id->adap.name), "Cadence I2C at %08lx", (unsigned long)r_mem->start); -- 2.17.1
