[PATCH V2] platform/x86: intel_pmc_core: Add CNP SLPS0 debug registers

From: David E. Box
Date: Fri May 25 2018 - 07:59:09 EST


Adds debugfs access to registers in the Cannon Point PCH PMC that are
useful for debugging #SLP_S0 signal assertion and other low power related
activities. Device pm states are latched in these registers whenever the
package enters C10 and can be read from slp_s0_debug_status. The pm
states may also be latched by writing 1 to slp_s0_dbg_latch which will
immediately capture the current state on the next read of
slp_s0_debug_status. Also while in intel_pmc_core.h clean up spacing.

Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
---

V2:
Per Andy Shevchenko:
- Clear latch bit after use
- Pass pmc_dev as parameter
- Use DEFINE_SHOW_ATTRIBUTE macro

drivers/platform/x86/intel_pmc_core.c | 112 ++++++++++++++++++++++++++++++++++
drivers/platform/x86/intel_pmc_core.h | 27 +++++---
2 files changed, 132 insertions(+), 7 deletions(-)

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index 43bbe74..ed40999 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -196,9 +196,64 @@ static const struct pmc_bit_map cnp_pfear_map[] = {
{}
};

+static const struct pmc_bit_map cnp_slps0_dbg0_map[] = {
+ {"AUDIO_D3", BIT(0)},
+ {"OTG_D3", BIT(1)},
+ {"XHCI_D3", BIT(2)},
+ {"LPIO_D3", BIT(3)},
+ {"SDX_D3", BIT(4)},
+ {"SATA_D3", BIT(5)},
+ {"UFS0_D3", BIT(6)},
+ {"UFS1_D3", BIT(7)},
+ {"EMMC_D3", BIT(8)},
+};
+
+static const struct pmc_bit_map cnp_slps0_dbg1_map[] = {
+ {"SDIO_PLL_OFF", BIT(0)},
+ {"USB2_PLL_OFF", BIT(1)},
+ {"AUDIO_PLL_OFF", BIT(2)},
+ {"OC_PLL_OFF", BIT(3)},
+ {"MAIN_PLL_OFF", BIT(4)},
+ {"XOSC_OFF", BIT(5)},
+ {"LPC_CLKS_GATED", BIT(6)},
+ {"PCIE_CLKREQS_IDLE", BIT(7)},
+ {"AUDIO_ROSC_OFF", BIT(8)},
+ {"HPET_XOSC_CLK_REQ", BIT(9)},
+ {"PMC_ROSC_SLOW_CLK", BIT(10)},
+ {"AON2_ROSC_GATED", BIT(11)},
+ {"CLKACKS_DEASSERTED", BIT(12)},
+};
+
+static const struct pmc_bit_map cnp_slps0_dbg2_map[] = {
+ {"MPHY_CORE_GATED", BIT(0)},
+ {"CSME_GATED", BIT(1)},
+ {"USB2_SUS_GATED", BIT(2)},
+ {"DYN_FLEX_IO_IDLE", BIT(3)},
+ {"GBE_NO_LINK", BIT(4)},
+ {"THERM_SEN_DISABLED", BIT(5)},
+ {"PCIE_LOW_POWER", BIT(6)},
+ {"ISH_VNNAON_REQ_ACT", BIT(7)},
+ {"ISH_VNN_REQ_ACT", BIT(8)},
+ {"CNV_VNNAON_REQ_ACT", BIT(9)},
+ {"CNV_VNN_REQ_ACT", BIT(10)},
+ {"NPK_VNNON_REQ_ACT", BIT(11)},
+ {"PMSYNC_STATE_IDLE", BIT(12)},
+ {"ALST_GT_THRES", BIT(13)},
+ {"PMC_ARC_PG_READY", BIT(14)},
+};
+
+static const struct slps0_dbg_map cnp_slps0_dbg_maps[] = {
+ {cnp_slps0_dbg0_map, ARRAY_SIZE(cnp_slps0_dbg0_map)},
+ {cnp_slps0_dbg1_map, ARRAY_SIZE(cnp_slps0_dbg1_map)},
+ {cnp_slps0_dbg2_map, ARRAY_SIZE(cnp_slps0_dbg2_map)},
+};
+
static const struct pmc_reg_map cnp_reg_map = {
.pfear_sts = cnp_pfear_map,
.slp_s0_offset = CNP_PMC_SLP_S0_RES_COUNTER_OFFSET,
+ .slps0_dbg_maps = cnp_slps0_dbg_maps,
+ .slps0_dbg_offset = CNP_PMC_SLPS0_DBG_OFFSET,
+ .slps0_dbg_num = ARRAY_SIZE(cnp_slps0_dbg_maps),
.ltr_ignore_offset = CNP_PMC_LTR_IGNORE_OFFSET,
.regmap_length = CNP_PMC_MMIO_REG_LEN,
.ppfear0_offset = CNP_PMC_HOST_PPFEAR0A,
@@ -252,6 +307,8 @@ static int pmc_core_check_read_lock_bit(void)
}

#if IS_ENABLED(CONFIG_DEBUG_FS)
+static bool slps0_dbg_latch;
+
static void pmc_core_display_map(struct seq_file *s, int index,
u8 pf_reg, const struct pmc_bit_map *pf_map)
{
@@ -481,6 +538,52 @@ static const struct file_operations pmc_core_ltr_ignore_ops = {
.release = single_release,
};

+static void pmc_core_slps0_dbg_latch(struct pmc_dev *pmcdev, bool reset)
+{
+ const struct pmc_reg_map *map = pmcdev->map;
+ u32 fd;
+
+ mutex_lock(&pmcdev->lock);
+
+ if (!reset && !slps0_dbg_latch)
+ goto out_unlock;
+
+ fd = pmc_core_reg_read(pmcdev, map->slps0_dbg_offset);
+ reset ? (fd &= ~CNP_PMC_LATCH_SLPS0_EVENTS) :
+ (fd |= CNP_PMC_LATCH_SLPS0_EVENTS);
+ pmc_core_reg_write(pmcdev, map->slps0_dbg_offset, fd);
+
+ slps0_dbg_latch = 0;
+
+out_unlock:
+ mutex_unlock(&pmcdev->lock);
+}
+
+static int pmc_core_slps0_dbg_show(struct seq_file *s, void *unused)
+{
+ struct pmc_dev *pmcdev = s ? s->private : &pmc;
+ const struct slps0_dbg_map *maps = pmcdev->map->slps0_dbg_maps;
+ int num_slps0_dbg_regs = pmcdev->map->slps0_dbg_num;
+ int i, offset;
+ u32 data;
+
+ pmc_core_slps0_dbg_latch(pmcdev, false);
+ offset = pmcdev->map->slps0_dbg_offset;
+ while (num_slps0_dbg_regs--) {
+ data = pmc_core_reg_read(pmcdev, offset);
+ offset += 4;
+ for (i = 0; i < maps->size; i++)
+ seq_printf(s, "SLP_S0_DBG: %-32s\tState: %s\n",
+ maps->slps0_dbg_sts[i].name,
+ data & maps->slps0_dbg_sts[i].bit_mask ?
+ "Yes" : "No");
+ maps++;
+ }
+ pmc_core_slps0_dbg_latch(pmcdev, true);
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(pmc_core_slps0_dbg);
+
static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
{
debugfs_remove_recursive(pmcdev->dbgfs_dir);
@@ -514,6 +617,15 @@ static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
0444, dir, pmcdev,
&pmc_core_mphy_pg_ops);

+ if (pmcdev->map->slps0_dbg_maps) {
+ debugfs_create_file("slp_s0_debug_status", 0444,
+ dir, pmcdev,
+ &pmc_core_slps0_dbg_fops);
+
+ debugfs_create_bool("slp_s0_dbg_latch", 0644,
+ dir, &slps0_dbg_latch);
+ }
+
return 0;
}
#else
diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h
index 5fa5f97..97e4b5a 100644
--- a/drivers/platform/x86/intel_pmc_core.h
+++ b/drivers/platform/x86/intel_pmc_core.h
@@ -124,27 +124,35 @@ enum ppfear_regs {
#define SPT_PMC_BIT_MPHY_CMN_LANE3 BIT(3)

/* Cannonlake Power Management Controller register offsets */
-#define CNP_PMC_SLP_S0_RES_COUNTER_OFFSET 0x193C
-#define CNP_PMC_LTR_IGNORE_OFFSET 0x1B0C
-#define CNP_PMC_PM_CFG_OFFSET 0x1818
+#define CNP_PMC_SLP_S0_RES_COUNTER_OFFSET 0x193C
+#define CNP_PMC_LTR_IGNORE_OFFSET 0x1B0C
+#define CNP_PMC_PM_CFG_OFFSET 0x1818
+#define CNP_PMC_SLPS0_DBG_OFFSET 0x10B4
/* Cannonlake: PGD PFET Enable Ack Status Register(s) start */
-#define CNP_PMC_HOST_PPFEAR0A 0x1D90
+#define CNP_PMC_HOST_PPFEAR0A 0x1D90

-#define CNP_PMC_MMIO_REG_LEN 0x2000
-#define CNP_PPFEAR_NUM_ENTRIES 8
-#define CNP_PMC_READ_DISABLE_BIT 22
+#define CNP_PMC_MMIO_REG_LEN 0x2000
+#define CNP_PPFEAR_NUM_ENTRIES 8
+#define CNP_PMC_READ_DISABLE_BIT 22
+#define CNP_PMC_LATCH_SLPS0_EVENTS BIT(31)

struct pmc_bit_map {
const char *name;
u32 bit_mask;
};

+struct slps0_dbg_map {
+ const struct pmc_bit_map *slps0_dbg_sts;
+ int size;
+};
+
/**
* struct pmc_reg_map - Structure used to define parameter unique to a
PCH family
* @pfear_sts: Maps name of IP block to PPFEAR* bit
* @mphy_sts: Maps name of MPHY lane to MPHY status lane status bit
* @pll_sts: Maps name of PLL to corresponding bit status
+ * @slps0_dbg_maps: Array of SLP_S0_DBG* registers containing debug info
* @slp_s0_offset: PWRMBASE offset to read SLP_S0 residency
* @ltr_ignore_offset: PWRMBASE offset to read/write LTR ignore bit
* @regmap_length: Length of memory to map from PWRMBASE address to access
@@ -153,6 +161,8 @@ struct pmc_bit_map {
* PPFEAR
* @pm_cfg_offset: PWRMBASE offset to PM_CFG register
* @pm_read_disable_bit: Bit index to read PMC_READ_DISABLE
+ * @slps0_dbg_offset: PWRMBASE offset to SLP_S0_DEBUG_REG*
+ * @slps0_dbg_num: Number of SLP_S0_DEBUG_REG registers
*
* Each PCH has unique set of register offsets and bit indexes. This structure
* captures them to have a common implementation.
@@ -161,6 +171,7 @@ struct pmc_reg_map {
const struct pmc_bit_map *pfear_sts;
const struct pmc_bit_map *mphy_sts;
const struct pmc_bit_map *pll_sts;
+ const struct slps0_dbg_map *slps0_dbg_maps;
const u32 slp_s0_offset;
const u32 ltr_ignore_offset;
const int regmap_length;
@@ -168,6 +179,8 @@ struct pmc_reg_map {
const int ppfear_buckets;
const u32 pm_cfg_offset;
const int pm_read_disable_bit;
+ const u32 slps0_dbg_offset;
+ const int slps0_dbg_num;
};

/**
--
2.7.4