[PATCH 3/4] platform/x86: pmc_atom: Check state of PMC clocks on s2idle

[Hans de Goede <hdegoede@redhat.com>]

Extend the s2idle check with checking that none of the PMC clocks
is in the forced on state. If one of the clocks is in forced on
state then S0i3 cannot be reached.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/platform/x86/pmc_atom.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/platform/x86/pmc_atom.c b/drivers/platform/x86/pmc_atom.c
index e14d489fa6f9..375010ef61ae 100644
--- a/drivers/platform/x86/pmc_atom.c
+++ b/drivers/platform/x86/pmc_atom.c
@@ -20,6 +20,14 @@
 #include <linux/seq_file.h>
 #include <linux/suspend.h>
 
+#define PMC_CLK_CTL_OFFSET		0x60
+#define PMC_CLK_NUM			6
+#define PMC_CLK_CTL_GATED_ON_D3		0x0
+#define PMC_CLK_CTL_FORCE_ON		0x1
+#define PMC_CLK_CTL_FORCE_OFF		0x2
+#define PMC_CLK_CTL_RESERVED		0x3
+#define PMC_MASK_CLK_CTL		GENMASK(1, 0)
+
 struct pmc_bit_map {
 	const char *name;
 	u32 bit_mask;
@@ -477,6 +485,7 @@ static void pmc_s2idle_check(void)
 	u32 func_dis, func_dis_2;
 	u32 d3_sts_0, d3_sts_1;
 	u32 false_pos_sts_0, false_pos_sts_1;
+	int i;
 
 	func_dis = pmc_reg_read(pmc, PMC_FUNC_DIS);
 	func_dis_2 = pmc_reg_read(pmc, PMC_FUNC_DIS_2);
@@ -504,6 +513,16 @@ static void pmc_s2idle_check(void)
 
 	/* High part */
 	pmc_dev_state_check(d3_sts_1, m->d3_sts_1, func_dis_2, m->func_dis_2, false_pos_sts_1);
+
+	/* Check PMC clocks */
+	for (i = 0; i < PMC_CLK_NUM; i++) {
+		u32 ctl = pmc_reg_read(pmc, PMC_CLK_CTL_OFFSET + 4 * i);
+
+		if ((ctl & PMC_MASK_CLK_CTL) != PMC_CLK_CTL_FORCE_ON)
+			continue;
+
+		pr_err("pmc_atom: clk %d is ON prior to freeze (ctl %08x)\n", i, ctl);
+	}
 }
 
 static struct acpi_s2idle_dev_ops pmc_s2idle_ops = {
-- 
2.43.0