platform/x86: intel_pmc_core: Handle sub-states generically

The current implementation of pmc_core_substate_res_show() is written
specifically for Tiger Lake. However, new platform will also have
sub-states and may support different modes. Therefore rewrite the code to
handle sub-states generically.

Obtain the number and type of enabled states form the PMC. Use the Low
Power Mode (LPM) priority register to store the states in order from
shallowest to deepest for displays. Add a for_each macro to simplify
this. While changing the sub-state display it makes sense to show only the
"enabled" sub-states instead of showing all possible ones. After this
patch, the debugfs file looks like this:

Substate   Residency
S0i2.0     0
S0i3.0     0
S0i2.1     9329279
S0i3.1     0
S0i3.2     0

Suggested-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>
Link: https://lore.kernel.org/r/20210417031252.3020837-4-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

1 files changed, 48 insertions, 11 deletions

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index e8474d171d23..c02f63c00ecc 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -579,8 +579,9 @@ static const struct pmc_reg_map tgl_reg_map = {
 	.pm_cfg_offset = CNP_PMC_PM_CFG_OFFSET,
 	.pm_read_disable_bit = CNP_PMC_READ_DISABLE_BIT,
 	.ltr_ignore_max = TGL_NUM_IP_IGN_ALLOWED,
-	.lpm_modes = tgl_lpm_modes,
+	.lpm_num_maps = TGL_LPM_NUM_MAPS,
 	.lpm_en_offset = TGL_LPM_EN_OFFSET,
+	.lpm_priority_offset = TGL_LPM_PRI_OFFSET,
 	.lpm_residency_offset = TGL_LPM_RESIDENCY_OFFSET,
 	.lpm_sts = tgl_lpm_maps,
 	.lpm_status_offset = TGL_LPM_STATUS_OFFSET,
@@ -1140,18 +1141,14 @@ DEFINE_SHOW_ATTRIBUTE(pmc_core_ltr);
 static int pmc_core_substate_res_show(struct seq_file *s, void *unused)
 {
 	struct pmc_dev *pmcdev = s->private;
-	const char **lpm_modes = pmcdev->map->lpm_modes;
 	u32 offset = pmcdev->map->lpm_residency_offset;
-	u32 lpm_en;
-	int index;
+	int i, mode;
 
-	lpm_en = pmc_core_reg_read(pmcdev, pmcdev->map->lpm_en_offset);
-	seq_printf(s, "status substate residency\n");
-	for (index = 0; lpm_modes[index]; index++) {
-		seq_printf(s, "%7s %7s %-15u\n",
-			   BIT(index) & lpm_en ? "Enabled" : " ",
-			   lpm_modes[index], pmc_core_reg_read(pmcdev, offset));
-		offset += 4;
+	seq_printf(s, "%-10s %-15s\n", "Substate", "Residency");
+
+	pmc_for_each_mode(i, mode, pmcdev) {
+		seq_printf(s, "%-10s %-15u\n", pmc_lpm_modes[mode],
+			   pmc_core_reg_read(pmcdev, offset + (4 * mode)));
 	}
 
 	return 0;
@@ -1203,6 +1200,45 @@ static int pmc_core_pkgc_show(struct seq_file *s, void *unused)
 }
 DEFINE_SHOW_ATTRIBUTE(pmc_core_pkgc);
 
+static void pmc_core_get_low_power_modes(struct pmc_dev *pmcdev)
+{
+	u8 lpm_priority[LPM_MAX_NUM_MODES];
+	u32 lpm_en;
+	int mode, i, p;
+
+	/* Use LPM Maps to indicate support for substates */
+	if (!pmcdev->map->lpm_num_maps)
+		return;
+
+	lpm_en = pmc_core_reg_read(pmcdev, pmcdev->map->lpm_en_offset);
+	pmcdev->num_lpm_modes = hweight32(lpm_en);
+
+	/* Each byte contains information for 2 modes (7:4 and 3:0) */
+	for (mode = 0; mode < LPM_MAX_NUM_MODES; mode += 2) {
+		u8 priority = pmc_core_reg_read_byte(pmcdev,
+				pmcdev->map->lpm_priority_offset + (mode / 2));
+		int pri0 = GENMASK(3, 0) & priority;
+		int pri1 = (GENMASK(7, 4) & priority) >> 4;
+
+		lpm_priority[pri0] = mode;
+		lpm_priority[pri1] = mode + 1;
+	}
+
+	/*
+	 * Loop though all modes from lowest to highest priority,
+	 * and capture all enabled modes in order
+	 */
+	i = 0;
+	for (p = LPM_MAX_NUM_MODES - 1; p >= 0; p--) {
+		int mode = lpm_priority[p];
+
+		if (!(BIT(mode) & lpm_en))
+			continue;
+
+		pmcdev->lpm_en_modes[i++] = mode;
+	}
+}
+
 static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
 {
 	debugfs_remove_recursive(pmcdev->dbgfs_dir);
@@ -1379,6 +1415,7 @@ static int pmc_core_probe(struct platform_device *pdev)
 
 	mutex_init(&pmcdev->lock);
 	pmcdev->pmc_xram_read_bit = pmc_core_check_read_lock_bit(pmcdev);
+	pmc_core_get_low_power_modes(pmcdev);
 	pmc_core_do_dmi_quirks(pmcdev);
 
 	/*