Commit 616228a1 authored by Juergen Beisert's avatar Juergen Beisert Committed by Wolfram Sang
Browse files

i2c: mxs: distinguish i.MX23 and i.MX28 based I2C controller 



It seems the PIO mode does not work, or at least not like it works
on a i.MX28. Each short transfer needs about one second (without an
error message) but does not send anything on the I2C lines.

Signed-off-by: default avatarJuergen Beisert <jbe@pengutronix.de>
Signed-off-by: default avatarMarek Vasut <marex@denx.de>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 0acc2b32

drivers/i2c/busses/i2c-mxs.c

+34 −6
Original line number Diff line number Diff line
@@ -95,10 +95,17 @@ 
#define MXS_CMD_I2C_READ	(MXS_I2C_CTRL0_SEND_NAK_ON_LAST | \

				 MXS_I2C_CTRL0_MASTER_MODE)



enum mxs_i2c_devtype {

	MXS_I2C_UNKNOWN = 0,

	MXS_I2C_V1,

	MXS_I2C_V2,

};



/**

 * struct mxs_i2c_dev - per device, private MXS-I2C data

 *

 * @dev: driver model device node

 * @dev_type: distinguish i.MX23/i.MX28 features

 * @regs: IO registers pointer

 * @cmd_complete: completion object for transaction wait

 * @cmd_err: error code for last transaction
@@ -106,6 +113,7 @@ 
 */

struct mxs_i2c_dev {

	struct device *dev;

	enum mxs_i2c_devtype dev_type;

	void __iomem *regs;

	struct completion cmd_complete;

	int cmd_err;
@@ -495,6 +503,7 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, 
	 * is set to 8 bytes, transfers shorter than 8 bytes are transfered

	 * using PIO mode while longer transfers use DMA. The 8 byte border is

	 * based on this empirical measurement and a lot of previous frobbing.

	 * Note: this special feature only works on i.MX28 SoC

	 */

	i2c->cmd_err = 0;

	if (0) {	/* disable PIO mode until a proper fix is made */
@@ -680,8 +689,28 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c) 
	return 0;

}



static struct platform_device_id mxs_i2c_devtype[] = {

	{

		.name = "imx23-i2c",

		.driver_data = MXS_I2C_V1,

	}, {

		.name = "imx28-i2c",

		.driver_data = MXS_I2C_V2,

	}, { /* sentinel */ }

};

MODULE_DEVICE_TABLE(platform, mxs_i2c_devtype);



static const struct of_device_id mxs_i2c_dt_ids[] = {

	{ .compatible = "fsl,imx23-i2c", .data = &mxs_i2c_devtype[0], },

	{ .compatible = "fsl,imx28-i2c", .data = &mxs_i2c_devtype[1], },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, mxs_i2c_dt_ids);



static int mxs_i2c_probe(struct platform_device *pdev)

{

	const struct of_device_id *of_id =

				of_match_device(mxs_i2c_dt_ids, &pdev->dev);

	struct device *dev = &pdev->dev;

	struct mxs_i2c_dev *i2c;

	struct i2c_adapter *adap;
@@ -693,6 +722,11 @@ static int mxs_i2c_probe(struct platform_device *pdev) 
	if (!i2c)

		return -ENOMEM;



	if (of_id) {

		const struct platform_device_id *device_id = of_id->data;

		i2c->dev_type = device_id->driver_data;

	}



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	irq = platform_get_irq(pdev, 0);
@@ -768,12 +802,6 @@ static int mxs_i2c_remove(struct platform_device *pdev) 
	return 0;

}



static const struct of_device_id mxs_i2c_dt_ids[] = {

	{ .compatible = "fsl,imx28-i2c", },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, mxs_i2c_dt_ids);



static struct platform_driver mxs_i2c_driver = {

	.driver = {

		   .name = DRIVER_NAME,

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