From 41a3fa66a0d8a6b134ceb17b8f34520cad7643a4 Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Thu, 25 Aug 2016 15:42:04 -0500 Subject: soc/intel/apollolake: add option for SLP_S3_L assertion width In order to provide time for the S0 rails to discharge one needs to be able to set the SLP_S3_L assertion width. The hardware default is 60 microcseconds which is not slow enough on most boards. Therefore provide a devicetree option for the mainboard to set accordingly for its needs. An unset value in devicetree results in a conservative 2 second SLP_S3_L duration. BUG=chrome-os-partner:56581 Change-Id: I6c6df2f7a181746708ab7897249ae82109c55f50 Signed-off-by: Aaron Durbin Reviewed-on: https://review.coreboot.org/16326 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel Reviewed-by: Andrey Petrov --- src/soc/intel/apollolake/pmc.c | 59 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) (limited to 'src/soc/intel/apollolake/pmc.c') diff --git a/src/soc/intel/apollolake/pmc.c b/src/soc/intel/apollolake/pmc.c index 30b7677a92..c58314494c 100644 --- a/src/soc/intel/apollolake/pmc.c +++ b/src/soc/intel/apollolake/pmc.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "chip.h" /* @@ -132,12 +133,70 @@ static void pch_set_acpi_mode(void) } } +static int choose_slp_s3_assertion_width(int width_usecs) +{ + int i; + static const struct { + int max_width; + int value; + } slp_s3_settings[] = { + { + .max_width = 60, + .value = SLP_S3_ASSERT_60_USEC, + }, + { + .max_width = 1 * USECS_PER_MSEC, + .value = SLP_S3_ASSERT_1_MSEC, + }, + { + .max_width = 50 * USECS_PER_MSEC, + .value = SLP_S3_ASSERT_50_MSEC, + }, + { + .max_width = 2 * USECS_PER_SEC, + .value = SLP_S3_ASSERT_2_SEC, + }, + }; + + for (i = 0; i < ARRAY_SIZE(slp_s3_settings); i++) { + if (width_usecs <= slp_s3_settings[i].max_width) + break; + } + + /* Provide conservative default if nothing set in devicetree + * or requested assertion width too large. */ + if (width_usecs <= 0 || i == ARRAY_SIZE(slp_s3_settings)) + i = ARRAY_SIZE(slp_s3_settings) - 1; + + printk(BIOS_DEBUG, "SLP S3 assertion width: %d usecs\n", + slp_s3_settings[i].max_width); + + return slp_s3_settings[i].value; +} + +static void set_slp_s3_assertion_width(int width_usecs) +{ + uint32_t reg; + uintptr_t gen_pmcon3 = get_pmc_mmio_bar() + GEN_PMCON3; + int setting = choose_slp_s3_assertion_width(width_usecs); + + reg = read32((void *)gen_pmcon3); + reg &= ~SLP_S3_ASSERT_MASK; + reg |= setting << SLP_S3_ASSERT_WIDTH_SHIFT; + write32((void *)gen_pmcon3, reg); +} + static void pmc_init(struct device *dev) { + const struct soc_intel_apollolake_config *cfg = dev->chip_info; + /* Set up GPE configuration */ pmc_gpe_init(); pch_set_acpi_mode(); + if (cfg != NULL) + set_slp_s3_assertion_width(cfg->slp_s3_assertion_width_usecs); + /* Log power state */ pch_log_state(); } -- cgit v1.2.3