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authorCharles Keepax <ckeepax@opensource.wolfsonmicro.com>2015-05-11 13:58:03 +0100
committerLee Jones <lee.jones@linaro.org>2015-06-22 12:25:10 +0100
commit1c1c6bba57f51331f64f32d0ce9a0f9883041205 (patch)
treec6ea3a4948ca6bd53049216ce3e3fac3e3b08fdb /drivers/mfd
parent2229875dc00f38b95d04fecfc67858ba2221a563 (diff)
downloadop-kernel-dev-1c1c6bba57f51331f64f32d0ce9a0f9883041205.zip
op-kernel-dev-1c1c6bba57f51331f64f32d0ce9a0f9883041205.tar.gz
mfd: wm5102: Ensure we always boot the device fully
The wm5102 uses a custom boot sequence and the standard boot sequence is disabled. However, the standard boot sequence must be run at least once after a cold boot (caused by either a hard reset or removal of AVDD). Unfortunately the register WRITE_SEQUENCER_CTRL_3 is not affected by the hardware reset. This means if the device has been previously booted but the AVDD supply has never been removed, arizona_dev_init will reset the chip but the boot sequence will not run, which can cause numerous problems. The solution is to manually clear this register and then boot the chip again, which is what this patch does. Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/arizona-core.c50
1 files changed, 40 insertions, 10 deletions
diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
index f30d925..0df1299 100644
--- a/drivers/mfd/arizona-core.c
+++ b/drivers/mfd/arizona-core.c
@@ -344,6 +344,33 @@ err_fll:
return err;
}
+static int wm5102_clear_write_sequencer(struct arizona *arizona)
+{
+ int ret;
+
+ ret = regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_3,
+ 0x0);
+ if (ret) {
+ dev_err(arizona->dev,
+ "Failed to clear write sequencer state: %d\n", ret);
+ return ret;
+ }
+
+ arizona_enable_reset(arizona);
+ regulator_disable(arizona->dcvdd);
+
+ msleep(20);
+
+ ret = regulator_enable(arizona->dcvdd);
+ if (ret) {
+ dev_err(arizona->dev, "Failed to re-enable DCVDD: %d\n", ret);
+ return ret;
+ }
+ arizona_disable_reset(arizona);
+
+ return 0;
+}
+
#ifdef CONFIG_PM
static int arizona_runtime_resume(struct device *dev)
{
@@ -802,21 +829,24 @@ int arizona_dev_init(struct arizona *arizona)
case WM5102:
ret = regmap_read(arizona->regmap,
ARIZONA_WRITE_SEQUENCER_CTRL_3, &val);
- if (ret != 0)
+ if (ret) {
dev_err(dev,
"Failed to check write sequencer state: %d\n",
ret);
- else if (val & 0x01)
- break;
- /* Fall through */
- default:
- ret = arizona_wait_for_boot(arizona);
- if (ret != 0) {
- dev_err(arizona->dev,
- "Device failed initial boot: %d\n", ret);
- goto err_reset;
+ } else if (val & 0x01) {
+ ret = wm5102_clear_write_sequencer(arizona);
+ if (ret)
+ return ret;
}
break;
+ default:
+ break;
+ }
+
+ ret = arizona_wait_for_boot(arizona);
+ if (ret) {
+ dev_err(arizona->dev, "Device failed initial boot: %d\n", ret);
+ goto err_reset;
}
/* Read the device ID information & do device specific stuff */
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