pwm: sti: Initialise PWM capture device data

Each PWM capture device is allocated a structure to hold its own state.
During a capture the device may be partaking in one of 3 phases. Initial
(rising) phase change, a subsequent (falling) phase change indicating
end of the duty-cycle phase and finally a final (rising) phase change
indicating the end of the period. The timer value snapshot each event is
held in a variable of the same name, and the phase number (0, 1, 2) is
contained in the index variable. Other device specific information, such
as GPIO pin, the IRQ wait queue and locking is also contained in the
structure. This patch initialises this structure for each of the
available devices.

Signed-off-by: Lee Jones <[email protected]>
Signed-off-by: Thierry Reding <[email protected]>

Author: Lee Jones

drivers/pwm/pwm-sti.c

@@ -11,15 +11,18 @@
  */
 
 #include <linux/clk.h>
+#include <linux/interrupt.h>
 #include <linux/math64.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/regmap.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/time.h>
+#include <linux/wait.h>
 
 #define PWM_OUT_VAL(x)	(0x00 + (4 * (x))) /* Device's Duty Cycle register */
 #define PWM_CPT_VAL(x)	(0x10 + (4 * (x))) /* Capture value */
@@ -64,9 +67,17 @@ enum sti_cpt_edge {
 	CPT_EDGE_BOTH,
 };
 
+struct sti_cpt_ddata {
+	u32 snapshot[3];
+	unsigned int index;
+	struct mutex lock;
+	wait_queue_head_t wait;
+};
+
 struct sti_pwm_compat_data {
 	const struct reg_field *reg_fields;
-	unsigned int num_devs;
+	unsigned int pwm_num_devs;
+	unsigned int cpt_num_devs;
 	unsigned int max_pwm_cnt;
 	unsigned int max_prescale;
 };
@@ -307,10 +318,15 @@ static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
 	struct device_node *np = dev->of_node;
 	struct sti_pwm_compat_data *cdata = pc->cdata;
 	u32 num_devs;
+	int ret;
 
-	of_property_read_u32(np, "st,pwm-num-chan", &num_devs);
-	if (num_devs)
-		cdata->num_devs = num_devs;
+	ret = of_property_read_u32(np, "st,pwm-num-chan", &num_devs);
+	if (!ret)
+		cdata->pwm_num_devs = num_devs;
+
+	ret = of_property_read_u32(np, "st,capture-num-chan", &num_devs);
+	if (!ret)
+		cdata->cpt_num_devs = num_devs;
 
 	reg_fields = cdata->reg_fields;
 
@@ -350,6 +366,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 	struct sti_pwm_compat_data *cdata;
 	struct sti_pwm_chip *pc;
 	struct resource *res;
+	unsigned int i;
 	int ret;
 
 	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
@@ -378,7 +395,8 @@ static int sti_pwm_probe(struct platform_device *pdev)
 	cdata->reg_fields   = &sti_pwm_regfields[0];
 	cdata->max_prescale = 0xff;
 	cdata->max_pwm_cnt  = 255;
-	cdata->num_devs     = 1;
+	cdata->pwm_num_devs = 1;
+	cdata->cpt_num_devs = 0;
 
 	pc->cdata = cdata;
 	pc->dev = dev;
@@ -416,7 +434,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 	pc->chip.dev = dev;
 	pc->chip.ops = &sti_pwm_ops;
 	pc->chip.base = -1;
-	pc->chip.npwm = pc->cdata->num_devs;
+	pc->chip.npwm = pc->cdata->pwm_num_devs;
 	pc->chip.can_sleep = true;
 
 	ret = pwmchip_add(&pc->chip);
@@ -426,6 +444,19 @@ static int sti_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	for (i = 0; i < cdata->cpt_num_devs; i++) {
+		struct sti_cpt_ddata *ddata;
+
+		ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+		if (!ddata)
+			return -ENOMEM;
+
+		init_waitqueue_head(&ddata->wait);
+		mutex_init(&ddata->lock);
+
+		pwm_set_chip_data(&pc->chip.pwms[i], ddata);
+	}
+
 	platform_set_drvdata(pdev, pc);
 
 	return 0;
@@ -436,7 +467,7 @@ static int sti_pwm_remove(struct platform_device *pdev)
 	struct sti_pwm_chip *pc = platform_get_drvdata(pdev);
 	unsigned int i;
 
-	for (i = 0; i < pc->cdata->num_devs; i++)
+	for (i = 0; i < pc->cdata->pwm_num_devs; i++)
 		pwm_disable(&pc->chip.pwms[i]);
 
 	clk_unprepare(pc->pwm_clk);