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authorTim Wawrzynczak <twawrzynczak@chromium.org>2021-12-02 16:19:47 -0700
committerFelix Held <felix-coreboot@felixheld.de>2021-12-13 13:56:01 +0000
commit32f883e53275320f5b023bc9027da0db127874b8 (patch)
tree311a17612cd718910840a8027869ca8ec7f84732 /src/soc/intel/common/block
parentb0d3a019413d179d624690ff4065c84cdd759584 (diff)
soc/intel/common/block/pcie/rtd3: Add ModPHY power gate support for RTD3
For additional power savings during RTD3, the PMC can power-gate the ModPHY lanes that are used by the PCH PCIe root ports. Therefore, using the previous PCIe RP-type detection functions, implement ModPHY PG support for the PCH PCIe RPs. This involves: 1) Adding a mutex so only one power resource accesses the PMC registers at a time 2) OperationRegions to access the PMC's PG registers 3) Adding ModPHY PG enable sequence to _OFF 4) Adding ModPHY PG disable sequence to _ON BUG=b:197983574 TEST=50 S0ix suspend/resume cycles on brya0 Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org> Change-Id: I19cb05a74acfa3ded7867b1cac32c161a83b4f7d Reviewed-on: https://review.coreboot.org/c/coreboot/+/59855 Reviewed-by: Subrata Banik <subrata.banik@intel.com> Reviewed-by: Cliff Huang <cliff.huang@intel.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/soc/intel/common/block')
-rw-r--r--src/soc/intel/common/block/pcie/rtd3/rtd3.c84
1 files changed, 79 insertions, 5 deletions
diff --git a/src/soc/intel/common/block/pcie/rtd3/rtd3.c b/src/soc/intel/common/block/pcie/rtd3/rtd3.c
index 816df05b57..507c3c8dea 100644
--- a/src/soc/intel/common/block/pcie/rtd3/rtd3.c
+++ b/src/soc/intel/common/block/pcie/rtd3/rtd3.c
@@ -9,6 +9,8 @@
#include <device/pci.h>
#include <intelblocks/pmc.h>
#include <intelblocks/pmc_ipc.h>
+#include <intelblocks/pcie_rp.h>
+#include <soc/iomap.h>
#include "chip.h"
/*
@@ -42,6 +44,14 @@
#define ACPI_REG_PCI_L23_RDY_DETECT "L23R" /* L23_Rdy Detect Transition */
#define ACPI_REG_PCI_L23_SAVE_STATE "NCB7" /* Scratch bit to save L23 state */
+/* ACPI path to the mutex that protects accesses to PMC ModPhy power gating registers */
+#define RTD3_MUTEX_PATH "\\_SB.PCI0.R3MX"
+
+enum modphy_pg_state {
+ PG_DISABLE = 0,
+ PG_ENABLE = 1,
+};
+
/* Called from _ON to get PCIe link back to active state. */
static void pcie_rtd3_acpi_l23_exit(void)
{
@@ -74,12 +84,33 @@ static void pcie_rtd3_acpi_l23_entry(void)
acpigen_write_store_int_to_namestr(1, ACPI_REG_PCI_L23_SAVE_STATE);
}
+/* Called from _ON/_OFF to disable/enable ModPHY power gating */
+static void pcie_rtd3_enable_modphy_pg(unsigned int pcie_rp, enum modphy_pg_state state)
+{
+ /* Enter the critical section */
+ acpigen_emit_ext_op(ACQUIRE_OP);
+ acpigen_emit_namestring(RTD3_MUTEX_PATH);
+ acpigen_emit_word(ACPI_MUTEX_NO_TIMEOUT);
+
+ acpigen_write_store_int_to_namestr(state, "EMPG");
+ acpigen_write_delay_until_namestr_int(100, "AMPG", state);
+
+ /* Exit the critical section */
+ acpigen_emit_ext_op(RELEASE_OP);
+ acpigen_emit_namestring(RTD3_MUTEX_PATH);
+}
+
static void
pcie_rtd3_acpi_method_on(unsigned int pcie_rp,
- const struct soc_intel_common_block_pcie_rtd3_config *config)
+ const struct soc_intel_common_block_pcie_rtd3_config *config,
+ enum pcie_rp_type rp_type)
{
acpigen_write_method_serialized("_ON", 0);
+ /* Disable modPHY power gating for PCH RPs. */
+ if (rp_type == PCIE_RP_PCH)
+ pcie_rtd3_enable_modphy_pg(pcie_rp, PG_DISABLE);
+
/* Assert enable GPIO to turn on device power. */
if (config->enable_gpio.pin_count) {
acpigen_enable_tx_gpio(&config->enable_gpio);
@@ -98,7 +129,7 @@ pcie_rtd3_acpi_method_on(unsigned int pcie_rp,
acpigen_write_sleep(config->reset_delay_ms);
}
- /* Trigger L23 ready exit flow unless disabld by config. */
+ /* Trigger L23 ready exit flow unless disabled by config. */
if (!config->disable_l23)
pcie_rtd3_acpi_l23_exit();
@@ -107,7 +138,8 @@ pcie_rtd3_acpi_method_on(unsigned int pcie_rp,
static void
pcie_rtd3_acpi_method_off(int pcie_rp,
- const struct soc_intel_common_block_pcie_rtd3_config *config)
+ const struct soc_intel_common_block_pcie_rtd3_config *config,
+ enum pcie_rp_type rp_type)
{
acpigen_write_method_serialized("_OFF", 0);
@@ -122,6 +154,10 @@ pcie_rtd3_acpi_method_off(int pcie_rp,
acpigen_write_sleep(config->reset_off_delay_ms);
}
+ /* Enable modPHY power gating for PCH RPs */
+ if (rp_type == PCIE_RP_PCH)
+ pcie_rtd3_enable_modphy_pg(pcie_rp, PG_ENABLE);
+
/* Disable SRCCLK for this root port if pin is defined. */
if (config->srcclk_pin >= 0)
pmc_ipc_acpi_set_pci_clock(pcie_rp, config->srcclk_pin, false);
@@ -165,8 +201,31 @@ pcie_rtd3_acpi_method_status(int pcie_rp,
acpigen_pop_len(); /* Method */
}
+static void write_modphy_opregion(unsigned int pcie_rp)
+{
+ /* The register containing the Power Gate enable sequence bits is at
+ PCH_PWRM_BASE + 0x10D0, and the bits to check for sequence completion are at
+ PCH_PWRM_BASE + 0x10D4. */
+ const struct opregion opregion = OPREGION("PMCP", SYSTEMMEMORY,
+ PCH_PWRM_BASE_ADDRESS + 0x1000, 0xff);
+ const struct fieldlist fieldlist[] = {
+ FIELDLIST_OFFSET(0xD0),
+ FIELDLIST_RESERVED(pcie_rp),
+ FIELDLIST_NAMESTR("EMPG", 1), /* Enable ModPHY Power Gate */
+ FIELDLIST_OFFSET(0xD4),
+ FIELDLIST_RESERVED(pcie_rp),
+ FIELDLIST_NAMESTR("AMPG", 1), /* Is ModPHY Power Gate active? */
+ };
+
+ acpigen_write_opregion(&opregion);
+ acpigen_write_field("PMCP", fieldlist, ARRAY_SIZE(fieldlist),
+ FIELD_DWORDACC | FIELD_NOLOCK | FIELD_PRESERVE);
+}
+
static void pcie_rtd3_acpi_fill_ssdt(const struct device *dev)
{
+ static bool mutex_created = false;
+
const struct soc_intel_common_block_pcie_rtd3_config *config = config_of(dev);
static const char *const power_res_states[] = {"_PR0"};
const struct device *parent = dev->bus->dev;
@@ -206,6 +265,8 @@ static void pcie_rtd3_acpi_fill_ssdt(const struct device *dev)
return;
}
+ const enum pcie_rp_type rp_type = soc_get_pcie_rp_type(parent);
+
/* Read port number of root port that this device is attached to. */
pcie_rp = pci_read_config8(parent, PCH_PCIE_CFG_LCAP_PN);
if (pcie_rp == 0 || pcie_rp > CONFIG_MAX_ROOT_PORTS) {
@@ -218,21 +279,34 @@ static void pcie_rtd3_acpi_fill_ssdt(const struct device *dev)
printk(BIOS_INFO, "%s: Enable RTD3 for %s (%s)\n", scope, dev_path(parent),
config->desc ?: dev->chip_ops->name);
+ /* Create a mutex for exclusive access to the PMC registers. */
+ if (rp_type == PCIE_RP_PCH && !mutex_created) {
+ acpigen_write_scope("\\_SB.PCI0");
+ acpigen_write_mutex("R3MX", 0);
+ acpigen_write_scope_end();
+ mutex_created = true;
+ }
+
/* The RTD3 power resource is added to the root port, not the device. */
acpigen_write_scope(scope);
if (config->desc)
acpigen_write_name_string("_DDN", config->desc);
+ /* Create OpRegions for MMIO accesses. */
acpigen_write_opregion(&opregion);
acpigen_write_field("PXCS", fieldlist, ARRAY_SIZE(fieldlist),
FIELD_ANYACC | FIELD_NOLOCK | FIELD_PRESERVE);
+ /* Create the OpRegion to access the ModPHY PG registers (PCH RPs only) */
+ if (rp_type == PCIE_RP_PCH)
+ write_modphy_opregion(pcie_rp);
+
/* ACPI Power Resource for controlling the attached device power. */
acpigen_write_power_res("RTD3", 0, 0, power_res_states, ARRAY_SIZE(power_res_states));
pcie_rtd3_acpi_method_status(pcie_rp, config);
- pcie_rtd3_acpi_method_on(pcie_rp, config);
- pcie_rtd3_acpi_method_off(pcie_rp, config);
+ pcie_rtd3_acpi_method_on(pcie_rp, config, rp_type);
+ pcie_rtd3_acpi_method_off(pcie_rp, config, rp_type);
acpigen_pop_len(); /* PowerResource */
/* Indicate to the OS that device supports hotplug in D3. */