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i2c: mv64xxx: Add bus error recovery

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This adds i2c bus recovery to the mv64xxx driver.

Implement bus recovery to recover from SCL/SDA stuck low.

This uses the generic recovery function, setting the clock/data lines as
GPIO pins, and sending 9 clocks to try and recover the bus.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
[wsa: added some curly braces]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Mark Tomlinson 2020-08-27 10:35:16 +12:00 committed by Wolfram Sang
parent 5df324b5f4
commit 9c7cae2427
1 changed files with 28 additions and 1 deletions
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29
drivers/i2c/busses/i2c-mv64xxx.c
View file

@ -17,6 +17,7 @@
#include <linux/interrupt.h>
#include <linux/mv643xx_i2c.h>
#include <linux/platform_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/reset.h>
#include <linux/io.h>
#include <linux/of.h>
@ -147,6 +148,7 @@ struct mv64xxx_i2c_data {
bool irq_clear_inverted;
/* Clk div is 2 to the power n, not 2 to the power n + 1 */
bool clk_n_base_0;
struct i2c_bus_recovery_info rinfo;
};
static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = {
@ -325,7 +327,8 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
drv_data->msg->flags);
drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
mv64xxx_i2c_hw_init(drv_data);
drv_data->rc = -EIO;
i2c_recover_bus(&drv_data->adapter);
drv_data->rc = -EAGAIN;
}
}
@ -561,6 +564,7 @@ mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
"time_left: %d\n", drv_data->block,
(int)time_left);
mv64xxx_i2c_hw_init(drv_data);
i2c_recover_bus(&drv_data->adapter);
}
} else
spin_unlock_irqrestore(&drv_data->lock, flags);
@ -870,6 +874,25 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
}
#endif /* CONFIG_OF */
static int mv64xxx_i2c_init_recovery_info(struct mv64xxx_i2c_data *drv_data,
struct device *dev)
{
struct i2c_bus_recovery_info *rinfo = &drv_data->rinfo;
rinfo->pinctrl = devm_pinctrl_get(dev);
if (IS_ERR(rinfo->pinctrl)) {
if (PTR_ERR(rinfo->pinctrl) == -EPROBE_DEFER)
return -EPROBE_DEFER;
dev_info(dev, "can't get pinctrl, bus recovery not supported\n");
return PTR_ERR(rinfo->pinctrl);
} else if (!rinfo->pinctrl) {
return -ENODEV;
}
drv_data->adapter.bus_recovery_info = rinfo;
return 0;
}
static int
mv64xxx_i2c_probe(struct platform_device *pd)
{
@ -926,6 +949,10 @@ mv64xxx_i2c_probe(struct platform_device *pd)
goto exit_reset;
}
rc = mv64xxx_i2c_init_recovery_info(drv_data, &pd->dev);
if (rc == -EPROBE_DEFER)
goto exit_reset;
drv_data->adapter.dev.parent = &pd->dev;
drv_data->adapter.algo = &mv64xxx_i2c_algo;
drv_data->adapter.owner = THIS_MODULE;