drm/amd: add pm domain for ACP IP sub blocks

ACP IP have internal DMA controller, DW I2S controller and DSPs
as separate power tiles. DMA and I2S devices are added to generic
pm domain, so that entire IP can be powered off/on at appropriate
times. Unused DSPs are made to be powered off though they are powered
on during ACP pm domain power on sequence.
Signed-off-by: Maruthi Bayyavarapu <maruthi.bayyavarapu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/acp/Kconfig

@@ -4,6 +4,7 @@ config DRM_AMD_ACP
        bool "Enable ACP IP support"
        default y
        select MFD_CORE
+       select PM_GENERIC_DOMAINS if PM
        help
 	Choose this option to enable ACP IP support for AMD SOCs.
 

drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c

@@ -24,6 +24,7 @@
  */
 
 #include <linux/irqdomain.h>
+#include <linux/pm_domain.h>
 #include <linux/platform_device.h>
 #include <sound/designware_i2s.h>
 #include <sound/pcm.h>
@@ -102,6 +103,155 @@ static int acp_sw_fini(void *handle)
 	return 0;
 }
 
+/* power off a tile/block within ACP */
+static int acp_suspend_tile(void *cgs_dev, int tile)
+{
+	u32 val = 0;
+	u32 count = 0;
+
+	if ((tile  < ACP_TILE_P1) || (tile > ACP_TILE_DSP2)) {
+		pr_err("Invalid ACP tile : %d to suspend\n", tile);
+		return -1;
+	}
+
+	val = cgs_read_register(cgs_dev, mmACP_PGFSM_READ_REG_0 + tile);
+	val &= ACP_TILE_ON_MASK;
+
+	if (val == 0x0) {
+		val = cgs_read_register(cgs_dev, mmACP_PGFSM_RETAIN_REG);
+		val = val | (1 << tile);
+		cgs_write_register(cgs_dev, mmACP_PGFSM_RETAIN_REG, val);
+		cgs_write_register(cgs_dev, mmACP_PGFSM_CONFIG_REG,
+					0x500 + tile);
+
+		count = ACP_TIMEOUT_LOOP;
+		while (true) {
+			val = cgs_read_register(cgs_dev, mmACP_PGFSM_READ_REG_0
+								+ tile);
+			val = val & ACP_TILE_ON_MASK;
+			if (val == ACP_TILE_OFF_MASK)
+				break;
+			if (--count == 0) {
+				pr_err("Timeout reading ACP PGFSM status\n");
+				return -ETIMEDOUT;
+			}
+			udelay(100);
+		}
+
+		val = cgs_read_register(cgs_dev, mmACP_PGFSM_RETAIN_REG);
+
+		val |= ACP_TILE_OFF_RETAIN_REG_MASK;
+		cgs_write_register(cgs_dev, mmACP_PGFSM_RETAIN_REG, val);
+	}
+	return 0;
+}
+
+/* power on a tile/block within ACP */
+static int acp_resume_tile(void *cgs_dev, int tile)
+{
+	u32 val = 0;
+	u32 count = 0;
+
+	if ((tile  < ACP_TILE_P1) || (tile > ACP_TILE_DSP2)) {
+		pr_err("Invalid ACP tile to resume\n");
+		return -1;
+	}
+
+	val = cgs_read_register(cgs_dev, mmACP_PGFSM_READ_REG_0 + tile);
+	val = val & ACP_TILE_ON_MASK;
+
+	if (val != 0x0) {
+		cgs_write_register(cgs_dev, mmACP_PGFSM_CONFIG_REG,
+					0x600 + tile);
+		count = ACP_TIMEOUT_LOOP;
+		while (true) {
+			val = cgs_read_register(cgs_dev, mmACP_PGFSM_READ_REG_0
+							+ tile);
+			val = val & ACP_TILE_ON_MASK;
+			if (val == 0x0)
+				break;
+			if (--count == 0) {
+				pr_err("Timeout reading ACP PGFSM status\n");
+				return -ETIMEDOUT;
+			}
+			udelay(100);
+		}
+		val = cgs_read_register(cgs_dev, mmACP_PGFSM_RETAIN_REG);
+		if (tile == ACP_TILE_P1)
+			val = val & (ACP_TILE_P1_MASK);
+		else if (tile == ACP_TILE_P2)
+			val = val & (ACP_TILE_P2_MASK);
+
+		cgs_write_register(cgs_dev, mmACP_PGFSM_RETAIN_REG, val);
+	}
+	return 0;
+}
+
+struct acp_pm_domain {
+	void *cgs_dev;
+	struct generic_pm_domain gpd;
+};
+
+static int acp_poweroff(struct generic_pm_domain *genpd)
+{
+	int i, ret;
+	struct acp_pm_domain *apd;
+
+	apd = container_of(genpd, struct acp_pm_domain, gpd);
+	if (apd != NULL) {
+		/* Donot return abruptly if any of power tile fails to suspend.
+		 * Log it and continue powering off other tile
+		 */
+		for (i = 4; i >= 0 ; i--) {
+			ret = acp_suspend_tile(apd->cgs_dev, ACP_TILE_P1 + i);
+			if (ret)
+				pr_err("ACP tile %d tile suspend failed\n", i);
+		}
+	}
+	return 0;
+}
+
+static int acp_poweron(struct generic_pm_domain *genpd)
+{
+	int i, ret;
+	struct acp_pm_domain *apd;
+
+	apd = container_of(genpd, struct acp_pm_domain, gpd);
+	if (apd != NULL) {
+		for (i = 0; i < 2; i++) {
+			ret = acp_resume_tile(apd->cgs_dev, ACP_TILE_P1 + i);
+			if (ret) {
+				pr_err("ACP tile %d resume failed\n", i);
+				break;
+			}
+		}
+
+		/* Disable DSPs which are not going to be used */
+		for (i = 0; i < 3; i++) {
+			ret = acp_suspend_tile(apd->cgs_dev, ACP_TILE_DSP0 + i);
+			/* Continue suspending other DSP, even if one fails */
+			if (ret)
+				pr_err("ACP DSP %d suspend failed\n", i);
+		}
+	}
+	return 0;
+}
+
+static struct device *get_mfd_cell_dev(const char *device_name, int r)
+{
+	char auto_dev_name[25];
+	char buf[8];
+	struct device *dev;
+
+	sprintf(buf, ".%d.auto", r);
+	strcpy(auto_dev_name, device_name);
+	strcat(auto_dev_name, buf);
+	dev = bus_find_device_by_name(&platform_bus_type, NULL, auto_dev_name);
+	dev_info(dev, "device %s added to pm domain\n", auto_dev_name);
+
+	return dev;
+}
+
 /**
  * acp_hw_init - start and test ACP block
  *
@@ -110,8 +260,9 @@ static int acp_sw_fini(void *handle)
  */
 static int acp_hw_init(void *handle)
 {
-	int r;
+	int r, i;
 	uint64_t acp_base;
+	struct device *dev;
 	struct i2s_platform_data *i2s_pdata;
 
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
@@ -137,6 +288,19 @@ static int acp_hw_init(void *handle)
 	else if (r)
 		return r;
 
+	adev->acp.acp_genpd = kzalloc(sizeof(struct acp_pm_domain), GFP_KERNEL);
+	if (adev->acp.acp_genpd == NULL)
+		return -ENOMEM;
+
+	adev->acp.acp_genpd->gpd.name = "ACP_AUDIO";
+	adev->acp.acp_genpd->gpd.power_off = acp_poweroff;
+	adev->acp.acp_genpd->gpd.power_on = acp_poweron;
+
+
+	adev->acp.acp_genpd->cgs_dev = adev->acp.cgs_device;
+
+	pm_genpd_init(&adev->acp.acp_genpd->gpd, NULL, false);
+
 	adev->acp.acp_cell = kzalloc(sizeof(struct mfd_cell) * ACP_DEVS,
 							GFP_KERNEL);
 
@@ -211,6 +375,15 @@ static int acp_hw_init(void *handle)
 	if (r)
 		return r;
 
+	for (i = 0; i < ACP_DEVS ; i++) {
+		dev = get_mfd_cell_dev(adev->acp.acp_cell[i].name, i);
+		r = pm_genpd_add_device(&adev->acp.acp_genpd->gpd, dev);
+		if (r) {
+			dev_err(dev, "Failed to add dev to genpd\n");
+			return r;
+		}
+	}
+
 	return 0;
 }
 
@@ -222,10 +395,22 @@ static int acp_hw_init(void *handle)
  */
 static int acp_hw_fini(void *handle)
 {
+	int i, ret;
+	struct device *dev;
+
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
+	for (i = 0; i < ACP_DEVS ; i++) {
+		dev = get_mfd_cell_dev(adev->acp.acp_cell[i].name, i);
+		ret = pm_genpd_remove_device(&adev->acp.acp_genpd->gpd, dev);
+		/* If removal fails, dont giveup and try rest */
+		if (ret)
+			dev_err(dev, "remove dev from genpd failed\n");
+	}
+
 	mfd_remove_devices(adev->acp.parent);
 	kfree(adev->acp.acp_res);
+	kfree(adev->acp.acp_genpd);
 	kfree(adev->acp.acp_cell);
 
 	return 0;
@@ -238,6 +423,25 @@ static int acp_suspend(void *handle)
 
 static int acp_resume(void *handle)
 {
+	int i, ret;
+	struct acp_pm_domain *apd;
+	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+
+	/* SMU block will power on ACP irrespective of ACP runtime status.
+	 * Power off explicitly based on genpd ACP runtime status so that ACP
+	 * hw and ACP-genpd status are in sync.
+	 * 'suspend_power_off' represents "Power status before system suspend"
+	*/
+	if (adev->acp.acp_genpd->gpd.suspend_power_off == true) {
+		apd = container_of(&adev->acp.acp_genpd->gpd,
+					struct acp_pm_domain, gpd);
+
+		for (i = 4; i >= 0 ; i--) {
+			ret = acp_suspend_tile(apd->cgs_dev, ACP_TILE_P1 + i);
+			if (ret)
+				pr_err("ACP tile %d tile suspend failed\n", i);
+		}
+	}
 	return 0;
 }
 

drivers/gpu/drm/amd/amdgpu/amdgpu_acp.h

@@ -34,6 +34,7 @@ struct amdgpu_acp {
 	struct amd_acp_private *private;
 	struct mfd_cell *acp_cell;
 	struct resource *acp_res;
+	struct acp_pm_domain *acp_genpd;
 };
 
 extern const struct amd_ip_funcs acp_ip_funcs;