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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-28 13:43:12 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-28 13:43:12 -0700 |
commit | a410963ba4c0c768302f0298e258b1ee940e8316 (patch) | |
tree | f262f101a5bf752ce14775da080aed5fbaf73f0e /drivers/i2c/busses/i2c-mxs.c | |
parent | f7da9cdf45cbbad5029d4858dcbc0134e06084ed (diff) | |
parent | 5db20c49e2d6581797c17057e068d89d6677aa24 (diff) | |
download | linux-a410963ba4c0c768302f0298e258b1ee940e8316.tar.gz linux-a410963ba4c0c768302f0298e258b1ee940e8316.tar.bz2 linux-a410963ba4c0c768302f0298e258b1ee940e8316.zip |
Merge branch 'i2c-embedded/for-next' of git://git.pengutronix.de/git/wsa/linux
Pull embedded i2c changes from Wolfram Sang:
"Changes for the "embedded" part of the I2C subsystem:
- lots of devicetree conversions of drivers (and preparations for
that)
- big cleanups for drivers for OMAP, Tegra, Nomadik, Blackfin
- Rafael's struct dev_pm_ops conversion patches for I2C
- usual driver cleanups and fixes
All patches have been in linux-next for an apropriate time and all
patches touching files outside of i2c-folders should have proper acks
from the maintainers."
* 'i2c-embedded/for-next' of git://git.pengutronix.de/git/wsa/linux: (60 commits)
Revert "i2c: tegra: convert normal suspend/resume to *_noirq"
I2C: MV64XYZ: Add Device Tree support
i2c: stu300: use devm managed resources
i2c: i2c-ocores: support for 16bit and 32bit IO
V4L/DVB: mfd: use reg_shift instead of regstep
i2c: i2c-ocores: Use reg-shift property
i2c: i2c-ocores: DT bindings and minor fixes.
i2c: mv64xxxx: remove EXPERIMENTAL tag
i2c-s3c2410: Use plain pm_runtime_put()
i2c: s3c2410: Fix pointer type passed to of_match_node()
i2c: mxs: Set I2C timing registers for mxs-i2c
i2c: i2c-bfin-twi: Move blackfin TWI register access Macro to head file.
i2c: i2c-bfin-twi: Move TWI peripheral pin request array to platform data.
i2c:i2c-bfin-twi: include twi head file
i2c:i2c-bfin-twi: TWI fails to restart next transfer in high system load.
i2c: i2c-bfin-twi: Tighten condition when failing I2C transfer if MEN bit is reset unexpectedly.
i2c: i2c-bfin-twi: Break dead waiting loop if i2c device misbehaves.
i2c: i2c-bfin-twi: Improve the patch for bug "Illegal i2c bus lock upon certain transfer scenarios".
i2c: i2c-bfin-twi: Illegal i2c bus lock upon certain transfer scenarios.
i2c-mv64xxxx: allow more than one driver instance
...
Conflicts:
drivers/i2c/busses/i2c-nomadik.c
Diffstat (limited to 'drivers/i2c/busses/i2c-mxs.c')
-rw-r--r-- | drivers/i2c/busses/i2c-mxs.c | 68 |
1 files changed, 67 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 04eb441b6ce1..088c5c1ed17d 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -46,6 +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) @@ -97,6 +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 * @@ -112,11 +145,17 @@ struct mxs_i2c_dev { struct completion cmd_complete; u32 cmd_err; struct i2c_adapter adapter; + const struct mxs_i2c_speed_config *speed; }; static void mxs_i2c_reset(struct mxs_i2c_dev *i2c) { 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); @@ -193,7 +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++) { @@ -319,6 +358,28 @@ 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; @@ -358,6 +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 */ |