Commit 9c7cae24 authored by Mark Tomlinson's avatar Mark Tomlinson Committed by Wolfram Sang
Browse files

i2c: mv64xxx: Add bus error recovery 



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: default avatarMark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
[wsa: added some curly braces]
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 5df324b5

drivers/i2c/busses/i2c-mv64xxx.c

+28 −1
Original line number Diff line number Diff line
@@ -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;