From f594d01bb4aff35dc582f5418e6823f79e28834b Mon Sep 17 00:00:00 2001 From: Charles Keepax Date: Tue, 27 Oct 2020 09:41:32 +0000 Subject: [PATCH] mfd: madera: Add special errata reset handling for cs47l15 An errata exists for cs47l15 where the reset must be handled differently and removed before DCVDD is applied. A soft reset is used for situations where a reset is required to reset state. This does however, make this part unsuitable for DCVDD supplies with a rise time greater than 2mS. Signed-off-by: Charles Keepax Signed-off-by: Lee Jones --- drivers/mfd/madera-core.c | 25 ++++++++++++++++++++----- include/linux/mfd/madera/core.h | 1 + 2 files changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c index a9c6f08..a2abc00 100644 --- a/drivers/mfd/madera-core.c +++ b/drivers/mfd/madera-core.c @@ -38,6 +38,9 @@ #define MADERA_RESET_MIN_US 2000 #define MADERA_RESET_MAX_US 3000 +#define ERRATA_DCVDD_MIN_US 10000 +#define ERRATA_DCVDD_MAX_US 15000 + static const char * const madera_core_supplies[] = { "AVDD", "DBVDD1", @@ -291,7 +294,8 @@ static int __maybe_unused madera_runtime_resume(struct device *dev) dev_dbg(dev, "Leaving sleep mode\n"); - madera_enable_hard_reset(madera); + if (!madera->reset_errata) + madera_enable_hard_reset(madera); ret = regulator_enable(madera->dcvdd); if (ret) { @@ -302,9 +306,12 @@ static int __maybe_unused madera_runtime_resume(struct device *dev) regcache_cache_only(madera->regmap, false); regcache_cache_only(madera->regmap_32bit, false); - madera_disable_hard_reset(madera); + if (madera->reset_errata) + usleep_range(ERRATA_DCVDD_MIN_US, ERRATA_DCVDD_MAX_US); + else + madera_disable_hard_reset(madera); - if (!madera->pdata.reset) { + if (!madera->pdata.reset || madera->reset_errata) { ret = madera_wait_for_boot(madera); if (ret) goto err; @@ -503,6 +510,8 @@ int madera_dev_init(struct madera *madera) */ switch (madera->type) { case CS47L15: + madera->reset_errata = true; + break; case CS47L35: case CS47L90: case CS47L91: @@ -553,13 +562,19 @@ int madera_dev_init(struct madera *madera) goto err_dcvdd; } + if (madera->reset_errata) + madera_disable_hard_reset(madera); + ret = regulator_enable(madera->dcvdd); if (ret) { dev_err(dev, "Failed to enable DCVDD: %d\n", ret); goto err_enable; } - madera_disable_hard_reset(madera); + if (madera->reset_errata) + usleep_range(ERRATA_DCVDD_MIN_US, ERRATA_DCVDD_MAX_US); + else + madera_disable_hard_reset(madera); regcache_cache_only(madera->regmap, false); regcache_cache_only(madera->regmap_32bit, false); @@ -667,7 +682,7 @@ int madera_dev_init(struct madera *madera) * It looks like a device we support. If we don't have a hard reset * we can now attempt a soft reset. */ - if (!madera->pdata.reset) { + if (!madera->pdata.reset || madera->reset_errata) { ret = madera_soft_reset(madera); if (ret) goto err_reset; diff --git a/include/linux/mfd/madera/core.h b/include/linux/mfd/madera/core.h index ad2c138..03a8a78 100644 --- a/include/linux/mfd/madera/core.h +++ b/include/linux/mfd/madera/core.h @@ -186,6 +186,7 @@ struct madera { struct regulator_bulk_data core_supplies[MADERA_MAX_CORE_SUPPLIES]; struct regulator *dcvdd; bool internal_dcvdd; + bool reset_errata; struct madera_pdata pdata; -- 2.7.4