From ea419b14d67d66e7512d4ea1f98cee6f2541c65a Mon Sep 17 00:00:00 2001
From: Steven Liu <steven.liu@rock-chips.com>
Date: Tue, 20 Oct 2020 15:19:21 +0800
Subject: [PATCH] pwm: rockchip: Support pwm oneshot mode for specified number
 of cycles.

The oneshot_count value should be less than PWM_ONESHOT_COUNT_MAX.
If oneshot_count == 0, this pwm channel works in continuous mode.

Signed-off-by: Steven Liu <steven.liu@rock-chips.com>
Change-Id: I45857fb5762e0365cce5278502479c580638e40c
---
 drivers/pwm/Kconfig        |  6 ++++++
 drivers/pwm/pwm-rockchip.c | 24 ++++++++++++++++++++++--
 include/linux/pwm.h        |  3 +++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 63be5362fd3a..ca5db43118d4 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -408,6 +408,12 @@ config PWM_ROCKCHIP
 	  Generic PWM framework driver for the PWM controller found on
 	  Rockchip SoCs.
 
+config PWM_ROCKCHIP_ONESHOT
+	bool "Rockchip PWM oneshot mode support"
+	depends on PWM_ROCKCHIP && NO_GKI
+	help
+	  Support Rockchip pwm oneshot mode for specified number of cycles.
+
 config PWM_SAMSUNG
 	tristate "Samsung PWM support"
 	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c
index 1f0131235561..157cf01cae69 100644
--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -30,6 +30,9 @@
 #define PWM_LOCK_EN		(1 << 6)
 #define PWM_LP_DISABLE		(0 << 8)
 
+#define PWM_ONESHOT_COUNT_SHIFT	24
+#define PWM_ONESHOT_COUNT_MAX	256
+
 struct rockchip_pwm_chip {
 	struct pwm_chip chip;
 	struct clk *clk;
@@ -39,6 +42,7 @@ struct rockchip_pwm_chip {
 	unsigned long clk_rate;
 	bool vop_pwm_en; /* indicate voppwm mirror register state */
 	bool center_aligned;
+	bool oneshot;
 };
 
 struct rockchip_pwm_regs {
@@ -130,6 +134,19 @@ static void rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			ctrl &= ~PWM_ENABLE;
 	}
 
+#ifdef CONFIG_PWM_ROCKCHIP_ONESHOT
+	if (state->oneshot_count > PWM_ONESHOT_COUNT_MAX) {
+		pc->oneshot = false;
+		dev_err(chip->dev, "Oneshot_count value overflow.\n");
+	} else if (state->oneshot_count > 0) {
+		pc->oneshot = true;
+		ctrl |= (state->oneshot_count - 1) << PWM_ONESHOT_COUNT_SHIFT;
+	} else {
+		pc->oneshot = false;
+		ctrl |= PWM_CONTINUOUS;
+	}
+#endif
+
 	if (pc->data->supports_lock) {
 		ctrl |= PWM_LOCK_EN;
 		writel_relaxed(ctrl, pc->base + pc->data->regs.ctrl);
@@ -181,10 +198,13 @@ static int rockchip_pwm_enable(struct pwm_chip *chip,
 			val |= PWM_OUTPUT_CENTER;
 	}
 
-	if (enable)
+	if (enable) {
 		val |= enable_conf;
-	else
+		if (pc->oneshot)
+			val &= ~PWM_CONTINUOUS;
+	} else {
 		val &= ~enable_conf;
+	}
 
 	writel_relaxed(val, pc->base + pc->data->regs.ctrl);
 	if (pc->data->vop_pwm)
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index f0a7329ba3b2..9212c2e80435 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -71,6 +71,9 @@ struct pwm_state {
 	u64 duty_cycle;
 	enum pwm_polarity polarity;
 	enum pwm_output_type output_type;
+#ifdef CONFIG_PWM_ROCKCHIP_ONESHOT
+	u64 oneshot_count;
+#endif /* CONFIG_PWM_ROCKCHIP_ONESHOT */
 	bool enabled;
 };