diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index 41d48a393e7f..857a53dc6c75 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -4,7 +4,9 @@
  * datasheet: https://www.ti.com/lit/ds/symlink/sn65dsi86.pdf
  */
 
+#include <linux/atomic.h>
 #include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/debugfs.h>
@@ -15,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/of_graph.h>
 #include <linux/pm_runtime.h>
+#include <linux/pwm.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 
@@ -91,6 +94,13 @@
 #define SN_ML_TX_MODE_REG			0x96
 #define  ML_TX_MAIN_LINK_OFF			0
 #define  ML_TX_NORMAL_MODE			BIT(0)
+#define SN_PWM_PRE_DIV_REG			0xA0
+#define SN_BACKLIGHT_SCALE_REG			0xA1
+#define  BACKLIGHT_SCALE_MAX			0xFFFF
+#define SN_BACKLIGHT_REG			0xA3
+#define SN_PWM_EN_INV_REG			0xA5
+#define  SN_PWM_INV_MASK			BIT(0)
+#define  SN_PWM_EN_MASK				BIT(1)
 #define SN_AUX_CMD_STATUS_REG			0xF4
 #define  AUX_IRQ_STATUS_AUX_RPLY_TOUT		BIT(3)
 #define  AUX_IRQ_STATUS_AUX_SHORT		BIT(5)
@@ -113,11 +123,14 @@
 
 #define SN_LINK_TRAINING_TRIES		10
 
+#define SN_PWM_GPIO_IDX			3 /* 4th GPIO */
+
 /**
  * struct ti_sn65dsi86 - Platform data for ti-sn65dsi86 driver.
  * @bridge_aux:   AUX-bus sub device for MIPI-to-eDP bridge functionality.
  * @gpio_aux:     AUX-bus sub device for GPIO controller functionality.
  * @aux_aux:      AUX-bus sub device for eDP AUX channel functionality.
+ * @pwm_aux:      AUX-bus sub device for PWM controller functionality.
  *
  * @dev:          Pointer to the top level (i2c) device.
  * @regmap:       Regmap for accessing i2c.
@@ -145,11 +158,17 @@
  *                bitmap so we can do atomic ops on it without an extra
  *                lock so concurrent users of our 4 GPIOs don't stomp on
  *                each other's read-modify-write.
+ *
+ * @pchip:        pwm_chip if the PWM is exposed.
+ * @pwm_enabled:  Used to track if the PWM signal is currently enabled.
+ * @pwm_pin_busy: Track if GPIO4 is currently requested for GPIO or PWM.
+ * @pwm_refclk_freq: Cache for the reference clock input to the PWM.
  */
 struct ti_sn65dsi86 {
 	struct auxiliary_device		bridge_aux;
 	struct auxiliary_device		gpio_aux;
 	struct auxiliary_device		aux_aux;
+	struct auxiliary_device		pwm_aux;
 
 	struct device			*dev;
 	struct regmap			*regmap;
@@ -172,6 +191,12 @@ struct ti_sn65dsi86 {
 	struct gpio_chip		gchip;
 	DECLARE_BITMAP(gchip_output, SN_NUM_GPIOS);
 #endif
+#if defined(CONFIG_PWM)
+	struct pwm_chip			pchip;
+	bool				pwm_enabled;
+	atomic_t			pwm_pin_busy;
+#endif
+	unsigned int			pwm_refclk_freq;
 };
 
 static const struct regmap_range ti_sn65dsi86_volatile_ranges[] = {
@@ -190,11 +215,31 @@ static const struct regmap_config ti_sn65dsi86_regmap_config = {
 	.cache_type = REGCACHE_NONE,
 };
 
+static int ti_sn65dsi86_read_u16(struct ti_sn65dsi86 *pdata,
+				 unsigned int reg, u16 *val)
+{
+	unsigned int tmp;
+	int ret;
+
+	ret = regmap_read(pdata->regmap, reg, &tmp);
+	if (ret)
+		return ret;
+	*val = tmp;
+
+	ret = regmap_read(pdata->regmap, reg + 1, &tmp);
+	if (ret)
+		return ret;
+	*val |= tmp << 8;
+
+	return 0;
+}
+
 static void ti_sn65dsi86_write_u16(struct ti_sn65dsi86 *pdata,
 				   unsigned int reg, u16 val)
 {
-	regmap_write(pdata->regmap, reg, val & 0xFF);
-	regmap_write(pdata->regmap, reg + 1, val >> 8);
+	u8 buf[2] = { val & 0xff, val >> 8 };
+
+	regmap_bulk_write(pdata->regmap, reg, &buf, ARRAY_SIZE(buf));
 }
 
 static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn65dsi86 *pdata)
@@ -253,6 +298,12 @@ static void ti_sn_bridge_set_refclk_freq(struct ti_sn65dsi86 *pdata)
 
 	regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
 			   REFCLK_FREQ(i));
+
+	/*
+	 * The PWM refclk is based on the value written to SN_DPPLL_SRC_REG,
+	 * regardless of its actual sourcing.
+	 */
+	pdata->pwm_refclk_freq = ti_sn_bridge_refclk_lut[i];
 }
 
 static void ti_sn65dsi86_enable_comms(struct ti_sn65dsi86 *pdata)
@@ -1259,9 +1310,283 @@ static struct auxiliary_driver ti_sn_bridge_driver = {
 };
 
 /* -----------------------------------------------------------------------------
- * GPIO Controller
+ * PWM Controller
+ */
+#if defined(CONFIG_PWM)
+static int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata)
+{
+	return atomic_xchg(&pdata->pwm_pin_busy, 1) ? -EBUSY : 0;
+}
+
+static void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata)
+{
+	atomic_set(&pdata->pwm_pin_busy, 0);
+}
+
+static struct ti_sn65dsi86 *pwm_chip_to_ti_sn_bridge(struct pwm_chip *chip)
+{
+	return container_of(chip, struct ti_sn65dsi86, pchip);
+}
+
+static int ti_sn_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
+
+	return ti_sn_pwm_pin_request(pdata);
+}
+
+static void ti_sn_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
+
+	ti_sn_pwm_pin_release(pdata);
+}
+
+/*
+ * Limitations:
+ * - The PWM signal is not driven when the chip is powered down, or in its
+ *   reset state and the driver does not implement the "suspend state"
+ *   described in the documentation. In order to save power, state->enabled is
+ *   interpreted as denoting if the signal is expected to be valid, and is used
+ *   to determine if the chip needs to be kept powered.
+ * - Changing both period and duty_cycle is not done atomically, neither is the
+ *   multi-byte register updates, so the output might briefly be undefined
+ *   during update.
  */
+static int ti_sn_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			   const struct pwm_state *state)
+{
+	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
+	unsigned int pwm_en_inv;
+	unsigned int backlight;
+	unsigned int pre_div;
+	unsigned int scale;
+	u64 period_max;
+	u64 period;
+	int ret;
+
+	if (!pdata->pwm_enabled) {
+		ret = pm_runtime_get_sync(pdata->dev);
+		if (ret < 0) {
+			pm_runtime_put_sync(pdata->dev);
+			return ret;
+		}
+	}
+
+	if (state->enabled) {
+		if (!pdata->pwm_enabled) {
+			/*
+			 * The chip might have been powered down while we
+			 * didn't hold a PM runtime reference, so mux in the
+			 * PWM function on the GPIO pin again.
+			 */
+			ret = regmap_update_bits(pdata->regmap, SN_GPIO_CTRL_REG,
+						 SN_GPIO_MUX_MASK << (2 * SN_PWM_GPIO_IDX),
+						 SN_GPIO_MUX_SPECIAL << (2 * SN_PWM_GPIO_IDX));
+			if (ret) {
+				dev_err(pdata->dev, "failed to mux in PWM function\n");
+				goto out;
+			}
+		}
+
+		/*
+		 * Per the datasheet the PWM frequency is given by:
+		 *
+		 *                          REFCLK_FREQ
+		 *   PWM_FREQ = -----------------------------------
+		 *               PWM_PRE_DIV * BACKLIGHT_SCALE + 1
+		 *
+		 * Unfortunately the math becomes overly complex unless we
+		 * assume that this formula is missing parenthesis around
+		 * BACKLIGHT_SCALE + 1.
+		 * With that the formula can be written:
+		 *
+		 *   T_pwm * REFCLK_FREQ = PWM_PRE_DIV * (BACKLIGHT_SCALE + 1)
+		 *
+		 * In order to keep BACKLIGHT_SCALE within its 16 bits,
+		 * PWM_PRE_DIV must be:
+		 *
+		 *                     T_pwm * REFCLK_FREQ
+		 *   PWM_PRE_DIV >= -------------------------
+		 *                   BACKLIGHT_SCALE_MAX + 1
+		 *
+		 * To simplify the search and optimize the resolution of the
+		 * PWM, the lowest possible PWM_PRE_DIV is used. Finally the
+		 * scale is calculated as:
+		 *
+		 *                      T_pwm * REFCLK_FREQ
+		 *   BACKLIGHT_SCALE = ---------------------- - 1
+		 *                          PWM_PRE_DIV
+		 *
+		 * Here T_pwm is represented in seconds, so appropriate scaling
+		 * to nanoseconds is necessary.
+		 */
+
+		/* Minimum T_pwm is (0 * 1) / REFCLK_FREQ */
+		if (state->period <= NSEC_PER_SEC / pdata->pwm_refclk_freq) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		/*
+		 * Maximum T_pwm is 255 * (65535 + 1) / REFCLK_FREQ
+		 * Limit period to this to avoid overflows
+		 */
+		period_max = div_u64((u64)NSEC_PER_SEC * 255 * (65535 + 1), pdata->pwm_refclk_freq);
+		if (period > period_max)
+			period = period_max;
+		else
+			period = state->period;
+
+		pre_div = DIV64_U64_ROUND_UP(period * pdata->pwm_refclk_freq,
+					     (u64)NSEC_PER_SEC * (BACKLIGHT_SCALE_MAX + 1));
+		scale = div64_u64(period * pdata->pwm_refclk_freq, (u64)NSEC_PER_SEC * pre_div) - 1;
+
+		/*
+		 * The documentation has the duty ratio given as:
+		 *
+		 *     duty          BACKLIGHT
+		 *   ------- = ---------------------
+		 *    period    BACKLIGHT_SCALE + 1
+		 *
+		 * Solve for BACKLIGHT, substituting BACKLIGHT_SCALE according
+		 * to definition above and adjusting for nanosecond
+		 * representation of duty cycle gives us:
+		 */
+		backlight = div64_u64(state->duty_cycle * pdata->pwm_refclk_freq, (u64)NSEC_PER_SEC * pre_div);
+		if (backlight > scale)
+			backlight = scale;
+
+		ret = regmap_write(pdata->regmap, SN_PWM_PRE_DIV_REG, pre_div);
+		if (ret) {
+			dev_err(pdata->dev, "failed to update PWM_PRE_DIV\n");
+			goto out;
+		}
 
+		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_SCALE_REG, scale);
+		ti_sn65dsi86_write_u16(pdata, SN_BACKLIGHT_REG, backlight);
+	}
+
+	pwm_en_inv = FIELD_PREP(SN_PWM_EN_MASK, state->enabled) |
+		     FIELD_PREP(SN_PWM_INV_MASK, state->polarity == PWM_POLARITY_INVERSED);
+	ret = regmap_write(pdata->regmap, SN_PWM_EN_INV_REG, pwm_en_inv);
+	if (ret) {
+		dev_err(pdata->dev, "failed to update PWM_EN/PWM_INV\n");
+		goto out;
+	}
+
+	pdata->pwm_enabled = state->enabled;
+out:
+
+	if (!pdata->pwm_enabled)
+		pm_runtime_put_sync(pdata->dev);
+
+	return ret;
+}
+
+static void ti_sn_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				struct pwm_state *state)
+{
+	struct ti_sn65dsi86 *pdata = pwm_chip_to_ti_sn_bridge(chip);
+	unsigned int pwm_en_inv;
+	unsigned int pre_div;
+	u16 backlight;
+	u16 scale;
+	int ret;
+
+	ret = regmap_read(pdata->regmap, SN_PWM_EN_INV_REG, &pwm_en_inv);
+	if (ret)
+		return;
+
+	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_SCALE_REG, &scale);
+	if (ret)
+		return;
+
+	ret = ti_sn65dsi86_read_u16(pdata, SN_BACKLIGHT_REG, &backlight);
+	if (ret)
+		return;
+
+	ret = regmap_read(pdata->regmap, SN_PWM_PRE_DIV_REG, &pre_div);
+	if (ret)
+		return;
+
+	state->enabled = FIELD_GET(SN_PWM_EN_MASK, pwm_en_inv);
+	if (FIELD_GET(SN_PWM_INV_MASK, pwm_en_inv))
+		state->polarity = PWM_POLARITY_INVERSED;
+	else
+		state->polarity = PWM_POLARITY_NORMAL;
+
+	state->period = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * (scale + 1),
+					 pdata->pwm_refclk_freq);
+	state->duty_cycle = DIV_ROUND_UP_ULL((u64)NSEC_PER_SEC * pre_div * backlight,
+					     pdata->pwm_refclk_freq);
+}
+
+static const struct pwm_ops ti_sn_pwm_ops = {
+	.request = ti_sn_pwm_request,
+	.free = ti_sn_pwm_free,
+	.apply = ti_sn_pwm_apply,
+	.get_state = ti_sn_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static int ti_sn_pwm_probe(struct auxiliary_device *adev,
+			   const struct auxiliary_device_id *id)
+{
+	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
+
+	pdata->pchip.dev = pdata->dev;
+	pdata->pchip.ops = &ti_sn_pwm_ops;
+	pdata->pchip.npwm = 1;
+	pdata->pchip.of_xlate = of_pwm_single_xlate;
+	pdata->pchip.of_pwm_n_cells = 1;
+
+	return pwmchip_add(&pdata->pchip);
+}
+
+static void ti_sn_pwm_remove(struct auxiliary_device *adev)
+{
+	struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
+
+	pwmchip_remove(&pdata->pchip);
+
+	if (pdata->pwm_enabled)
+		pm_runtime_put_sync(pdata->dev);
+}
+
+static const struct auxiliary_device_id ti_sn_pwm_id_table[] = {
+	{ .name = "ti_sn65dsi86.pwm", },
+	{},
+};
+
+static struct auxiliary_driver ti_sn_pwm_driver = {
+	.name = "pwm",
+	.probe = ti_sn_pwm_probe,
+	.remove = ti_sn_pwm_remove,
+	.id_table = ti_sn_pwm_id_table,
+};
+
+static int __init ti_sn_pwm_register(void)
+{
+	return auxiliary_driver_register(&ti_sn_pwm_driver);
+}
+
+static void ti_sn_pwm_unregister(void)
+{
+	auxiliary_driver_unregister(&ti_sn_pwm_driver);
+}
+
+#else
+static inline int ti_sn_pwm_pin_request(struct ti_sn65dsi86 *pdata) { return 0; }
+static inline void ti_sn_pwm_pin_release(struct ti_sn65dsi86 *pdata) {}
+
+static inline int ti_sn_pwm_register(void) { return 0; }
+static inline void ti_sn_pwm_unregister(void) {}
+#endif
+
+/* -----------------------------------------------------------------------------
+ * GPIO Controller
+ */
 #if defined(CONFIG_OF_GPIO)
 
 static int tn_sn_bridge_of_xlate(struct gpio_chip *chip,
@@ -1394,10 +1719,25 @@ static int ti_sn_bridge_gpio_direction_output(struct gpio_chip *chip,
 	return ret;
 }
 
+static int ti_sn_bridge_gpio_request(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
+
+	if (offset == SN_PWM_GPIO_IDX)
+		return ti_sn_pwm_pin_request(pdata);
+
+	return 0;
+}
+
 static void ti_sn_bridge_gpio_free(struct gpio_chip *chip, unsigned int offset)
 {
+	struct ti_sn65dsi86 *pdata = gpiochip_get_data(chip);
+
 	/* We won't keep pm_runtime if we're input, so switch there on free */
 	ti_sn_bridge_gpio_direction_input(chip, offset);
+
+	if (offset == SN_PWM_GPIO_IDX)
+		ti_sn_pwm_pin_release(pdata);
 }
 
 static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
@@ -1419,6 +1759,7 @@ static int ti_sn_gpio_probe(struct auxiliary_device *adev,
 	pdata->gchip.owner = THIS_MODULE;
 	pdata->gchip.of_xlate = tn_sn_bridge_of_xlate;
 	pdata->gchip.of_gpio_n_cells = 2;
+	pdata->gchip.request = ti_sn_bridge_gpio_request;
 	pdata->gchip.free = ti_sn_bridge_gpio_free;
 	pdata->gchip.get_direction = ti_sn_bridge_gpio_get_direction;
 	pdata->gchip.direction_input = ti_sn_bridge_gpio_direction_input;
@@ -1545,10 +1886,9 @@ static int ti_sn65dsi86_probe(struct i2c_client *client,
 	 * ordering. The bridge wants the panel to be there when it probes.
 	 * The panel wants its HPD GPIO (provided by sn65dsi86 on some boards)
 	 * when it probes. The panel and maybe backlight might want the DDC
-	 * bus. Soon the PWM provided by the bridge chip will have the same
-	 * problem. Having sub-devices allows the some sub devices to finish
-	 * probing even if others return -EPROBE_DEFER and gets us around the
-	 * problems.
+	 * bus or the pwm_chip. Having sub-devices allows the some sub devices
+	 * to finish probing even if others return -EPROBE_DEFER and gets us
+	 * around the problems.
 	 */
 
 	if (IS_ENABLED(CONFIG_OF_GPIO)) {
@@ -1557,6 +1897,12 @@ static int ti_sn65dsi86_probe(struct i2c_client *client,
 			return ret;
 	}
 
+	if (IS_ENABLED(CONFIG_PWM)) {
+		ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->pwm_aux, "pwm");
+		if (ret)
+			return ret;
+	}
+
 	/*
 	 * NOTE: At the end of the AUX channel probe we'll add the aux device
 	 * for the bridge. This is because the bridge can't be used until the
@@ -1600,10 +1946,14 @@ static int __init ti_sn65dsi86_init(void)
 	if (ret)
 		goto err_main_was_registered;
 
-	ret = auxiliary_driver_register(&ti_sn_aux_driver);
+	ret = ti_sn_pwm_register();
 	if (ret)
 		goto err_gpio_was_registered;
 
+	ret = auxiliary_driver_register(&ti_sn_aux_driver);
+	if (ret)
+		goto err_pwm_was_registered;
+
 	ret = auxiliary_driver_register(&ti_sn_bridge_driver);
 	if (ret)
 		goto err_aux_was_registered;
@@ -1612,6 +1962,8 @@ static int __init ti_sn65dsi86_init(void)
 
 err_aux_was_registered:
 	auxiliary_driver_unregister(&ti_sn_aux_driver);
+err_pwm_was_registered:
+	ti_sn_pwm_unregister();
 err_gpio_was_registered:
 	ti_sn_gpio_unregister();
 err_main_was_registered:
@@ -1625,6 +1977,7 @@ static void __exit ti_sn65dsi86_exit(void)
 {
 	auxiliary_driver_unregister(&ti_sn_bridge_driver);
 	auxiliary_driver_unregister(&ti_sn_aux_driver);
+	ti_sn_pwm_unregister();
 	ti_sn_gpio_unregister();
 	i2c_del_driver(&ti_sn65dsi86_driver);
 }
