Some devices (eg. Dell XPS 9530, 2023) due to a firmware bug have a
misconfigured clock divider, which should've been 1:1. This introduces
quirk which conditionally re-configures the clock divider to 1:1.
Signed-off-by: Aleksandrs Vinarskis <alex.vinarskis@xxxxxxxxx>
---
drivers/mfd/intel-lpss-pci.c | 5 +++++
drivers/mfd/intel-lpss.c | 7 +++++++
drivers/mfd/intel-lpss.h | 5 +++++
3 files changed, 17 insertions(+)
diff --git a/drivers/mfd/intel-lpss-pci.c b/drivers/mfd/intel-lpss-pci.c
index eb3b0195db2e..cab11ed23b4f 100644
--- a/drivers/mfd/intel-lpss-pci.c
+++ b/drivers/mfd/intel-lpss-pci.c
@@ -29,6 +29,11 @@ static const struct pci_device_id quirk_ids[] = {
PCI_DEVICE_SUB(PCI_VENDOR_ID_INTEL, 0x9d64, 0x152d, 0x1237),
.driver_data = QUIRK_IGNORE_RESOURCE_CONFLICTS,
},
+ {
+ /* Dell XPS 9530 (2023) */
+ PCI_DEVICE_SUB(PCI_VENDOR_ID_INTEL, 0x51fb, 0x1028, 0x0beb),
+ .driver_data = QUIRK_CLOCK_DIVIDER_UNITY,
+ },
{ }
};
diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
index 7af0a1fab062..d422e88ba491 100644
--- a/drivers/mfd/intel-lpss.c
+++ b/drivers/mfd/intel-lpss.c
@@ -292,6 +292,7 @@ static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
{
char name[32];
struct clk *tmp = *clk;
+ int ret;
snprintf(name, sizeof(name), "%s-enable", devname);
tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
@@ -308,6 +309,12 @@ static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
return PTR_ERR(tmp);
*clk = tmp;
+ if (lpss->info->quirks & QUIRK_CLOCK_DIVIDER_UNITY) {
+ ret = clk_set_rate(tmp, lpss->info->clk_rate);
+ if (ret)
+ return ret;
+ }
+
snprintf(name, sizeof(name), "%s-update", devname);
tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
diff --git a/drivers/mfd/intel-lpss.h b/drivers/mfd/intel-lpss.h
index f636059cbc71..f50d11d60d94 100644
--- a/drivers/mfd/intel-lpss.h
+++ b/drivers/mfd/intel-lpss.h
@@ -19,6 +19,11 @@
* Set to ignore resource conflicts with ACPI declared SystemMemory regions.
*/
#define QUIRK_IGNORE_RESOURCE_CONFLICTS BIT(0)
+/*
+ * Some devices have misconfigured clock divider due to a firmware bug.
+ * Set this to force the clock divider to 1:1 ratio.
+ */
+#define QUIRK_CLOCK_DIVIDER_UNITY BIT(1)
struct device;
struct resource;
--
2.40.1
