[PATCH v3] pinctrl: qcom: use scm_call to route GPIO irq to Apps

[Ansuel Smith <ansuelsmth@gmail.com>]

From: Ajay Kishore <akisho@codeaurora.org>

For IPQ806x targets, TZ protects the registers that are used to
configure the routing of interrupts to a target processor.
To resolve this, this patch uses scm call to route GPIO interrupts
to application processor. Also the scm call interface is changed.

Signed-off-by: Ajay Kishore <akisho@codeaurora.org>
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
v3:
* Rename route_to_apps to intr_target_use_scm
* Follow standard design and rename base_reg to phys_base
* Add additional comments in route interrupts condition 

v2:
* Move static varibale in msm_pinctrl struct
* Revert '4b024225c4a8 ("pinctrl: use devm_platform_ioremap_resource() to simplify code")'
  to get base_reg addr

 drivers/pinctrl/qcom/pinctrl-msm.c | 42 +++++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 6 deletions(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
index 9a8daa256a32..7d2a34beb1b6 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -22,6 +22,8 @@
 #include <linux/reboot.h>
 #include <linux/pm.h>
 #include <linux/log2.h>
+#include <linux/qcom_scm.h>
+#include <linux/io.h>
 
 #include <linux/soc/qcom/irq.h>
 
@@ -60,6 +62,8 @@ struct msm_pinctrl {
 	struct irq_chip irq_chip;
 	int irq;
 
+	bool intr_target_use_scm;
+
 	raw_spinlock_t lock;
 
 	DECLARE_BITMAP(dual_edge_irqs, MAX_NR_GPIO);
@@ -68,6 +72,7 @@ struct msm_pinctrl {
 
 	const struct msm_pinctrl_soc_data *soc;
 	void __iomem *regs[MAX_NR_TILES];
+	u32 phys_base[MAX_NR_TILES];
 };
 
 #define MSM_ACCESSOR(name) \
@@ -882,11 +887,31 @@ static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 	else
 		clear_bit(d->hwirq, pctrl->dual_edge_irqs);
 
-	/* Route interrupts to application cpu */
-	val = msm_readl_intr_target(pctrl, g);
-	val &= ~(7 << g->intr_target_bit);
-	val |= g->intr_target_kpss_val << g->intr_target_bit;
-	msm_writel_intr_target(val, pctrl, g);
+	/* Route interrupts to application cpu.
+	 * With intr_target_use_scm interrupts are routed to
+	 * application cpu using scm calls.
+	 */
+	if (pctrl->intr_target_use_scm) {
+		u32 addr = pctrl->phys_base[0] + g->intr_target_reg;
+		int ret;
+
+		qcom_scm_io_readl(addr, &val);
+
+		val &= ~(7 << g->intr_target_bit);
+		val |= g->intr_target_kpss_val << g->intr_target_bit;
+
+		ret = qcom_scm_io_writel(addr, val);
+		if (ret)
+			dev_err(pctrl->dev,
+				"Failed routing %lu interrupt to Apps proc",
+				d->hwirq);
+		}
+	} else {
+		val = msm_readl_intr_target(pctrl, g);
+		val &= ~(7 << g->intr_target_bit);
+		val |= g->intr_target_kpss_val << g->intr_target_bit;
+		msm_writel_intr_target(val, pctrl, g);
+	}
 
 	/* Update configuration for gpio.
 	 * RAW_STATUS_EN is left on for all gpio irqs. Due to the
@@ -1241,6 +1266,9 @@ int msm_pinctrl_probe(struct platform_device *pdev,
 	pctrl->dev = &pdev->dev;
 	pctrl->soc = soc_data;
 	pctrl->chip = msm_gpio_template;
+	pctrl->intr_target_use_scm = of_device_is_compatible(
+					pctrl->dev->of_node,
+					"qcom,ipq8064-pinctrl");
 
 	raw_spin_lock_init(&pctrl->lock);
 
@@ -1253,9 +1280,12 @@ int msm_pinctrl_probe(struct platform_device *pdev,
 				return PTR_ERR(pctrl->regs[i]);
 		}
 	} else {
-		pctrl->regs[0] = devm_platform_ioremap_resource(pdev, 0);
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+		pctrl->regs[0] = devm_ioremap_resource(&pdev->dev, res);
 		if (IS_ERR(pctrl->regs[0]))
 			return PTR_ERR(pctrl->regs[0]);
+
+		pctrl->phys_base[0] = res->start;
 	}
 
 	msm_pinctrl_setup_pm_reset(pctrl);
-- 
2.25.1