[PATCH v5 3/4] drm/xe/pm: Wire up suspend/resume for I2C controller

Heikki Krogerus
2025-06-27T13:53:34Z

From: Raag Jadav <raag.jadav@intel.com>

Wire up suspend/resume handles for I2C controller to match its power
state with SGUnit.

Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Karthik Poosa <karthik.poosa@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
drivers/gpu/drm/xe/regs/xe_i2c_regs.h | 5 +++++
drivers/gpu/drm/xe/xe_i2c.c | 29 +++++++++++++++++++++++++++
drivers/gpu/drm/xe/xe_i2c.h | 4 ++++
drivers/gpu/drm/xe/xe_pm.c | 9 +++++++++
4 files changed, 47 insertions(+)

diff --git a/drivers/gpu/drm/xe/regs/xe_i2c_regs.h b/drivers/gpu/drm/xe/regs/xe_i2c_regs.h
index 92dae4487614..af781c8e4a80 100644
--- a/drivers/gpu/drm/xe/regs/xe_i2c_regs.h
+++ b/drivers/gpu/drm/xe/regs/xe_i2c_regs.h
@@ -2,6 +2,8 @@
#ifndef _XE_I2C_REGS_H_
#define _XE_I2C_REGS_H_

+#include <linux/pci_regs.h>
+
#include "xe_reg_defs.h"
#include "xe_regs.h"

@@ -12,4 +14,7 @@
#define REG_SG_REMAP_ADDR_PREFIX XE_REG(SOC_BASE + 0x0164)
#define REG_SG_REMAP_ADDR_POSTFIX XE_REG(SOC_BASE + 0x0168)

+#define I2C_CONFIG_CMD XE_REG(I2C_CONFIG_SPACE_OFFSET + PCI_COMMAND)
+#define I2C_CONFIG_PMCSR XE_REG(I2C_CONFIG_SPACE_OFFSET + 0x84)
+
#endif /* _XE_I2C_REGS_H_ */
diff --git a/drivers/gpu/drm/xe/xe_i2c.c b/drivers/gpu/drm/xe/xe_i2c.c
index 172271469ceb..c22800256dcf 100644
--- a/drivers/gpu/drm/xe/xe_i2c.c
+++ b/drivers/gpu/drm/xe/xe_i2c.c
@@ -226,6 +226,31 @@ static const struct regmap_config i2c_regmap_config = {
.fast_io = true,
};

+void xe_i2c_pm_suspend(struct xe_device *xe)
+{
+ struct xe_mmio *mmio = xe_root_tile_mmio(xe);
+
+ if (!xe->i2c || xe->i2c->ep.cookie != XE_I2C_EP_COOKIE_DEVICE)
+ return;
+
+ xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D3hot);
+ drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR));
+}
+
+void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold)
+{
+ struct xe_mmio *mmio = xe_root_tile_mmio(xe);
+
+ if (!xe->i2c || xe->i2c->ep.cookie != XE_I2C_EP_COOKIE_DEVICE)
+ return;
+
+ if (d3cold)
+ xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_MEMORY);
+
+ xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D0);
+ drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR));
+}
+
static void xe_i2c_remove(void *data)
{
struct xe_i2c *i2c = data;
@@ -270,6 +295,10 @@ int xe_i2c_probe(struct xe_device *xe)
i2c->mmio = xe_root_tile_mmio(xe);
i2c->drm_dev = drm_dev;
i2c->ep = ep;
+ xe->i2c = i2c;
+
+ /* PCI PM isn't aware of this device, bring it up and match it with SGUnit state. */
+ xe_i2c_pm_resume(xe, true);

regmap = devm_regmap_init(drm_dev, NULL, i2c, &i2c_regmap_config);
if (IS_ERR(regmap))
diff --git a/drivers/gpu/drm/xe/xe_i2c.h b/drivers/gpu/drm/xe/xe_i2c.h
index 7ea40f4e4aa4..b767ed8ce52b 100644
--- a/drivers/gpu/drm/xe/xe_i2c.h
+++ b/drivers/gpu/drm/xe/xe_i2c.h
@@ -50,9 +50,13 @@ struct xe_i2c {
#if IS_ENABLED(CONFIG_I2C)
int xe_i2c_probe(struct xe_device *xe);
void xe_i2c_irq_handler(struct xe_device *xe, u32 master_ctl);
+void xe_i2c_pm_suspend(struct xe_device *xe);
+void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold);
#else
static inline int xe_i2c_probe(struct xe_device *xe) { return 0; }
static inline void xe_i2c_irq_handler(struct xe_device *xe, u32 master_ctl) { }
+static inline void xe_i2c_pm_suspend(struct xe_device *xe) { }
+static inline void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold) { }
#endif

#endif
diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 26e95460af87..46471e166b96 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -19,6 +19,7 @@
#include "xe_ggtt.h"
#include "xe_gt.h"
#include "xe_guc.h"
+#include "xe_i2c.h"
#include "xe_irq.h"
#include "xe_pcode.h"
#include "xe_pxp.h"
@@ -146,6 +147,8 @@ int xe_pm_suspend(struct xe_device *xe)

xe_display_pm_suspend_late(xe);

+ xe_i2c_pm_suspend(xe);
+
drm_dbg(&xe->drm, "Device suspended\n");
return 0;

@@ -191,6 +194,8 @@ int xe_pm_resume(struct xe_device *xe)
if (err)
goto err;

+ xe_i2c_pm_resume(xe, xe->d3cold.allowed);
+
xe_irq_resume(xe);

for_each_gt(gt, xe, id)
@@ -484,6 +489,8 @@ int xe_pm_runtime_suspend(struct xe_device *xe)

xe_display_pm_runtime_suspend_late(xe);

+ xe_i2c_pm_suspend(xe);
+
xe_rpm_lockmap_release(xe);
xe_pm_write_callback_task(xe, NULL);
return 0;
@@ -531,6 +538,8 @@ int xe_pm_runtime_resume(struct xe_device *xe)
goto out;
}

+ xe_i2c_pm_resume(xe, xe->d3cold.allowed);
+
xe_irq_resume(xe);

for_each_gt(gt, xe, id)
--
2.47.2