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gpio: pca953x: Restore registers after suspend/resume cycle

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It is possible that the PCA953x is powered down during suspend.
Use regmap cache to assure the registers in the PCA953x are in
line with the driver state after resume.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Marek Vasut 2018-12-12 02:40:02 +01:00 committed by Linus Walleij
parent 87813cf30a
commit b765743005
1 changed files with 88 additions and 0 deletions
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88
drivers/gpio/gpio-pca953x.c
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@ -975,6 +975,91 @@ static int pca953x_remove(struct i2c_client *client)
return ret;
}
#ifdef CONFIG_PM_SLEEP
static int pca953x_regcache_sync(struct device *dev)
{
struct pca953x_chip *chip = dev_get_drvdata(dev);
int ret;
/*
* The ordering between direction and output is important,
* sync these registers first and only then sync the rest.
*/
ret = regcache_sync_region(chip->regmap, chip->regs->direction,
chip->regs->direction + NBANK(chip));
if (ret != 0) {
dev_err(dev, "Failed to sync GPIO dir registers: %d\n", ret);
return ret;
}
ret = regcache_sync_region(chip->regmap, chip->regs->output,
chip->regs->output + NBANK(chip));
if (ret != 0) {
dev_err(dev, "Failed to sync GPIO out registers: %d\n", ret);
return ret;
}
#ifdef CONFIG_GPIO_PCA953X_IRQ
if (chip->driver_data & PCA_PCAL) {
ret = regcache_sync_region(chip->regmap, PCAL953X_IN_LATCH,
PCAL953X_IN_LATCH + NBANK(chip));
if (ret != 0) {
dev_err(dev, "Failed to sync INT latch registers: %d\n",
ret);
return ret;
}
ret = regcache_sync_region(chip->regmap, PCAL953X_INT_MASK,
PCAL953X_INT_MASK + NBANK(chip));
if (ret != 0) {
dev_err(dev, "Failed to sync INT mask registers: %d\n",
ret);
return ret;
}
}
#endif
return 0;
}
static int pca953x_suspend(struct device *dev)
{
struct pca953x_chip *chip = dev_get_drvdata(dev);
regcache_cache_only(chip->regmap, true);
regulator_disable(chip->regulator);
return 0;
}
static int pca953x_resume(struct device *dev)
{
struct pca953x_chip *chip = dev_get_drvdata(dev);
int ret;
ret = regulator_enable(chip->regulator);
if (ret != 0) {
dev_err(dev, "Failed to enable regulator: %d\n", ret);
return 0;
}
regcache_cache_only(chip->regmap, false);
regcache_mark_dirty(chip->regmap);
ret = pca953x_regcache_sync(dev);
if (ret)
return ret;
ret = regcache_sync(chip->regmap);
if (ret != 0) {
dev_err(dev, "Failed to restore register map: %d\n", ret);
return ret;
}
return 0;
}
#endif
/* convenience to stop overlong match-table lines */
#define OF_953X(__nrgpio, __int) (void *)(__nrgpio | PCA953X_TYPE | __int)
#define OF_957X(__nrgpio, __int) (void *)(__nrgpio | PCA957X_TYPE | __int)
@ -1018,9 +1103,12 @@ static const struct of_device_id pca953x_dt_ids[] = {
MODULE_DEVICE_TABLE(of, pca953x_dt_ids);
static SIMPLE_DEV_PM_OPS(pca953x_pm_ops, pca953x_suspend, pca953x_resume);
static struct i2c_driver pca953x_driver = {
.driver = {
.name = "pca953x",
.pm = &pca953x_pm_ops,
.of_match_table = pca953x_dt_ids,
.acpi_match_table = ACPI_PTR(pca953x_acpi_ids),
},