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| Started by | Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> |
|---|---|
| First post | 2016-04-06 00:30 +0200 |
| Last post | 2016-04-06 08:10 +0200 |
| Articles | 2 — 1 participant |
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Re: [PATCH 1/3] regulator: twl: Make sure we have access to powerbus before trying to write to it Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> - 2016-04-06 00:30 +0200
[PATCH] regulator: twl: Fix a typo in twl4030_send_pb_msg Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> - 2016-04-06 08:10 +0200
| From | Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> |
|---|---|
| Date | 2016-04-06 00:30 +0200 |
| Subject | Re: [PATCH 1/3] regulator: twl: Make sure we have access to powerbus before trying to write to it |
| Message-ID | <rkHDY-2qu-1@gated-at.bofh.it> |
On 26.03.2016 10:28, Ivaylo Dimitrov wrote:
> According to the TRM, we need to enable i2c access to powerbus before
> writing to it. Also, a new write to powerbus should not be attempted if
> there is a pending transfer. The current code does not implement that
> functionality and while there are no known problems caused by that, it is
> better to follow what TRM says.
>
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> ---
> drivers/regulator/twl-regulator.c | 78 +++++++++++++++++++++++++++++++++++----
> 1 file changed, 70 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/regulator/twl-regulator.c b/drivers/regulator/twl-regulator.c
> index 955a6fb..aad748b0 100644
> --- a/drivers/regulator/twl-regulator.c
> +++ b/drivers/regulator/twl-regulator.c
> @@ -21,7 +21,7 @@
> #include <linux/regulator/machine.h>
> #include <linux/regulator/of_regulator.h>
> #include <linux/i2c/twl.h>
> -
> +#include <linux/delay.h>
>
> /*
> * The TWL4030/TW5030/TPS659x0/TWL6030 family chips include power management, a
> @@ -188,6 +188,74 @@ static int twl6030reg_is_enabled(struct regulator_dev *rdev)
> return grp && (val == TWL6030_CFG_STATE_ON);
> }
>
> +#define PB_I2C_BUSY BIT(0)
> +#define PB_I2C_BWEN BIT(1)
> +
> +/* Wait until buffer empty/ready to send a word on power bus. */
> +static int twl4030_wait_pb_ready(void)
> +{
> +
> + int ret;
> + int timeout = 10;
> + u8 val;
> +
> + do {
> + ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
> + TWL4030_PM_MASTER_PB_CFG);
> + if (ret < 0)
> + return ret;
> +
> + if (!(val & PB_I2C_BUSY))
> + return 0;
> +
> + mdelay(1);
> + timeout--;
> + } while (timeout);
> +
> + return -ETIMEDOUT;
> +}
> +
> +/* Send a word over the powerbus */
> +static int twl4030_send_pb_msg(unsigned msg)
> +{
> + u8 val;
> + int ret;
> +
> + /* save powerbus configuration */
> + ret = twl_i2c_read_u8(TWL_MODULE_PM_MASTER, &val,
> + TWL4030_PM_MASTER_PB_CFG);
> + if (ret < 0)
> + return ret;
> +
> + /* Enable i2c access to powerbus */
> + ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val | PB_I2C_BWEN,
> + TWL4030_PM_MASTER_PB_CFG);
> + if (ret < 0)
> + return ret;
> +
> + ret = twl4030_wait_pb_ready();
> + if (ret < 0)
> + return ret;
> +
> + ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg >> 8,
> + TWL4030_PM_MASTER_PB_WORD_MSB);
> + if (ret < 0)
> + return ret;
> +
> + ret = twl_i2c_write_u8(TWL_MODULE_PM_MASTER, msg & 0xff,
> + TWL4030_PM_MASTER_PB_WORD_LSB);
> + if (ret < 0)
> + return ret;
> +
> + ret = twl4030_wait_pb_ready();
> + if (ret < 0)
> + return ret;
> +
> + /* Restore powerbus configuration */
> + return twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val,
> + TWL_MODULE_PM_MASTER);
Hmm, I made a copy/paste error here, this should be:
return twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val,
TWL4030_PM_MASTER_PB_CFG);
Will send a new version of the patch.
> +}
> +
> static int twl4030reg_enable(struct regulator_dev *rdev)
> {
> struct twlreg_info *info = rdev_get_drvdata(rdev);
> @@ -324,13 +392,7 @@ static int twl4030reg_set_mode(struct regulator_dev *rdev, unsigned mode)
> if (!(status & (P3_GRP_4030 | P2_GRP_4030 | P1_GRP_4030)))
> return -EACCES;
>
> - status = twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
> - message >> 8, TWL4030_PM_MASTER_PB_WORD_MSB);
> - if (status < 0)
> - return status;
> -
> - return twl_i2c_write_u8(TWL_MODULE_PM_MASTER,
> - message & 0xff, TWL4030_PM_MASTER_PB_WORD_LSB);
> + return twl4030_send_pb_msg(message);
> }
>
> static int twl6030reg_set_mode(struct regulator_dev *rdev, unsigned mode)
>
Ivo
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| From | Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> |
|---|---|
| Date | 2016-04-06 08:10 +0200 |
| Subject | [PATCH] regulator: twl: Fix a typo in twl4030_send_pb_msg |
| Message-ID | <rkOP7-84y-9@gated-at.bofh.it> |
| In reply to | #1372032 |
Commit <2330b05c095bdeaaf1261c54cd2d4b9127496996> ("regulator: twl: Make
sure we have access to powerbus before trying to write to it")
has implemented the needed logic to correctly access powerbus through i2c,
however it brought a typo when powerbus configuration is restored, which
results in writing to a wrong register. Fix that by providing the correct
register value.
Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
---
drivers/regulator/twl-regulator.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/regulator/twl-regulator.c b/drivers/regulator/twl-regulator.c
index 11c6a5c..faeb5ee 100644
--- a/drivers/regulator/twl-regulator.c
+++ b/drivers/regulator/twl-regulator.c
@@ -253,7 +253,7 @@ static int twl4030_send_pb_msg(unsigned msg)
/* Restore powerbus configuration */
return twl_i2c_write_u8(TWL_MODULE_PM_MASTER, val,
- TWL_MODULE_PM_MASTER);
+ TWL4030_PM_MASTER_PB_CFG);
}
static int twl4030reg_enable(struct regulator_dev *rdev)
--
1.9.1
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