diff options
| author | Juergen Beisert <jbe@pengutronix.de> | 2013-09-30 01:23:53 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2013-10-06 15:56:23 +0200 |
| commit | 616228a164d4366f82d983c4a70d8006d9fb43f2 (patch) | |
| tree | e9f46cd8b7cd8815131f41b26846f32a9a0e5284 /drivers/i2c | |
| parent | 0acc2b321342aa813fa9fc485afb09fbc811f594 (diff) | |
| download | talos-op-linux-616228a164d4366f82d983c4a70d8006d9fb43f2.tar.gz talos-op-linux-616228a164d4366f82d983c4a70d8006d9fb43f2.zip | |
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: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mxs.c | 40 |
1 files changed, 34 insertions, 6 deletions
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index f4a01675fa71..2cb0317b14fb 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -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, |
