[PATCH 07/11] soc: imx: gpcv2: add support for optional resets

[Lucas Stach]

Normally the reset for the devices inside the power domain is
triggered automatically from the PGC in the power-up sequencing,
however on i.MX8MM this doesn't work for the GPU power domains.

Add support for triggering the reset explicitly during the power
up sequencing.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 .../devicetree/bindings/power/fsl,imx-gpcv2.yaml    |  6 ++++++
 drivers/soc/imx/gpcv2.c                             | 13 +++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml b/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml
index bde09a0b2da3..9773771b9000 100644
--- a/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml
+++ b/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml
@@ -62,6 +62,12 @@ properties:
 
           power-supply: true
 
+          resets:
+            description: |
+              A number of phandles to resets that need to be asserted during
+              power-up sequencing of the domain.
+            minItems: 1
+
         required:
           - '#power-domain-cells'
           - reg
diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c
index db93fef0c76b..76aa8a67d8a7 100644
--- a/drivers/soc/imx/gpcv2.c
+++ b/drivers/soc/imx/gpcv2.c
@@ -15,6 +15,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
+#include <linux/reset.h>
 #include <linux/sizes.h>
 #include <dt-bindings/power/imx7-power.h>
 #include <dt-bindings/power/imx8mq-power.h>
@@ -112,6 +113,7 @@ struct imx_pgc_domain {
 	struct regulator *regulator;
 	struct clk *clk[GPC_CLK_MAX];
 	int num_clks;
+	struct reset_control *reset;
 
 	unsigned int pgc;
 
@@ -167,6 +169,8 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
 		}
 	}
 
+	reset_control_assert(domain->reset);
+
 	if (domain->bits.pxx) {
 		/* request the domain to power up */
 		regmap_update_bits(domain->regmap, GPC_PU_PGC_SW_PUP_REQ,
@@ -189,6 +193,8 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
 				   GPC_PGC_CTRL_PCR, 0);
 	}
 
+	reset_control_deassert(domain->reset);
+
 	/* request the ADB400 to power up */
 	if (domain->bits.hskreq) {
 		regmap_update_bits(domain->regmap, GPC_PU_PWRHSK,
@@ -577,6 +583,13 @@ static int imx_pgc_domain_probe(struct platform_device *pdev)
 				      domain->voltage, domain->voltage);
 	}
 
+	domain->reset = devm_reset_control_array_get_optional_exclusive(domain->dev);
+	if (IS_ERR(domain->reset)) {
+		if (PTR_ERR(domain->reset) != -EPROBE_DEFER)
+			dev_err(domain->dev, "Failed to get domain's reset\n");
+		return PTR_ERR(domain->reset);
+	}
+
 	ret = imx_pgc_get_clocks(domain);
 	if (ret) {
 		if (ret != -EPROBE_DEFER)
-- 
2.20.1