diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-mxs.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mxs.c | 96 |
1 files changed, 88 insertions, 8 deletions
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 76b8af44f634..088c5c1ed17d 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -26,8 +26,11 @@ #include <linux/platform_device.h> #include <linux/jiffies.h> #include <linux/io.h> - -#include <mach/common.h> +#include <linux/pinctrl/consumer.h> +#include <linux/stmp_device.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_i2c.h> #define DRIVER_NAME "mxs-i2c" @@ -43,6 +46,10 @@ #define MXS_I2C_CTRL0_DIRECTION 0x00010000 #define MXS_I2C_CTRL0_XFER_COUNT(v) ((v) & 0x0000FFFF) +#define MXS_I2C_TIMING0 (0x10) +#define MXS_I2C_TIMING1 (0x20) +#define MXS_I2C_TIMING2 (0x30) + #define MXS_I2C_CTRL1 (0x40) #define MXS_I2C_CTRL1_SET (0x44) #define MXS_I2C_CTRL1_CLR (0x48) @@ -94,6 +101,35 @@ #define MXS_CMD_I2C_READ (MXS_I2C_CTRL0_SEND_NAK_ON_LAST | \ MXS_I2C_CTRL0_MASTER_MODE) +struct mxs_i2c_speed_config { + uint32_t timing0; + uint32_t timing1; + uint32_t timing2; +}; + +/* + * Timing values for the default 24MHz clock supplied into the i2c block. + * + * The bus can operate at 95kHz or at 400kHz with the following timing + * register configurations. The 100kHz mode isn't present because it's + * values are not stated in the i.MX233/i.MX28 datasheet. The 95kHz mode + * shall be close enough replacement. Therefore when the bus is configured + * for 100kHz operation, 95kHz timing settings are actually loaded. + * + * For details, see i.MX233 [25.4.2 - 25.4.4] and i.MX28 [27.5.2 - 27.5.4]. + */ +static const struct mxs_i2c_speed_config mxs_i2c_95kHz_config = { + .timing0 = 0x00780030, + .timing1 = 0x00800030, + .timing2 = 0x00300030, +}; + +static const struct mxs_i2c_speed_config mxs_i2c_400kHz_config = { + .timing0 = 0x000f0007, + .timing1 = 0x001f000f, + .timing2 = 0x00300030, +}; + /** * struct mxs_i2c_dev - per device, private MXS-I2C data * @@ -109,15 +145,17 @@ struct mxs_i2c_dev { struct completion cmd_complete; u32 cmd_err; struct i2c_adapter adapter; + const struct mxs_i2c_speed_config *speed; }; -/* - * TODO: check if calls to here are really needed. If not, we could get rid of - * mxs_reset_block and the mach-dependency. Needs an I2C analyzer, probably. - */ static void mxs_i2c_reset(struct mxs_i2c_dev *i2c) { - mxs_reset_block(i2c->regs); + stmp_reset_block(i2c->regs); + + writel(i2c->speed->timing0, i2c->regs + MXS_I2C_TIMING0); + writel(i2c->speed->timing1, i2c->regs + MXS_I2C_TIMING1); + writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2); + writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET); writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, i2c->regs + MXS_I2C_QUEUECTRL_SET); @@ -194,7 +232,7 @@ static int mxs_i2c_wait_for_data(struct mxs_i2c_dev *i2c) static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len) { - u32 data; + u32 uninitialized_var(data); int i; for (i = 0; i < len; i++) { @@ -320,15 +358,42 @@ static const struct i2c_algorithm mxs_i2c_algo = { .functionality = mxs_i2c_func, }; +static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c) +{ + uint32_t speed; + struct device *dev = i2c->dev; + struct device_node *node = dev->of_node; + int ret; + + if (!node) + return -EINVAL; + + i2c->speed = &mxs_i2c_95kHz_config; + ret = of_property_read_u32(node, "clock-frequency", &speed); + if (ret) + dev_warn(dev, "No I2C speed selected, using 100kHz\n"); + else if (speed == 400000) + i2c->speed = &mxs_i2c_400kHz_config; + else if (speed != 100000) + dev_warn(dev, "Unsupported I2C speed selected, using 100kHz\n"); + + return 0; +} + static int __devinit mxs_i2c_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct mxs_i2c_dev *i2c; struct i2c_adapter *adap; + struct pinctrl *pinctrl; struct resource *res; resource_size_t res_size; int err, irq; + pinctrl = devm_pinctrl_get_select_default(dev); + if (IS_ERR(pinctrl)) + return PTR_ERR(pinctrl); + i2c = devm_kzalloc(dev, sizeof(struct mxs_i2c_dev), GFP_KERNEL); if (!i2c) return -ENOMEM; @@ -354,6 +419,11 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) return err; i2c->dev = dev; + + err = mxs_i2c_get_ofdata(i2c); + if (err) + return err; + platform_set_drvdata(pdev, i2c); /* Do reset to enforce correct startup after pinmuxing */ @@ -365,6 +435,7 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) adap->algo = &mxs_i2c_algo; adap->dev.parent = dev; adap->nr = pdev->id; + adap->dev.of_node = pdev->dev.of_node; i2c_set_adapdata(adap, i2c); err = i2c_add_numbered_adapter(adap); if (err) { @@ -374,6 +445,8 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) return err; } + of_i2c_register_devices(adap); + return 0; } @@ -393,10 +466,17 @@ static int __devexit 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, .owner = THIS_MODULE, + .of_match_table = mxs_i2c_dt_ids, }, .remove = __devexit_p(mxs_i2c_remove), }; |
