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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: dri-devel@lists.freedesktop.org
Subject: [PATCH v4 7/9] drm/panel: Add driver for the Sony ACX565AKM panel
Date: Tue, 13 Aug 2019 23:10:59 +0300
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This panel is used on the Nokia N900.

The code is based on the omapdrm-specific panel-sony-acx565akm driver.
The hardware-related logic has been changed as little as possible to
avoid regressions as hardware availability is lacking to test the
changes. Follow-up patches should address the items listed in the TODO
list.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
Changes since v3:

- Add TODO

Changes since v2:

- Call drm_panel_unprepare() in .remove() handler

Changes since v1:

- Mention boards using the panel in Kconfig
- Renamed acx565akm_device to acx565akm_panel
- Comments updates
- Store width_mm and height_mm in drm_display_mode
- Use drm_panel_disable() in .remove() handler
---
 drivers/gpu/drm/panel/Kconfig                |   8 +
 drivers/gpu/drm/panel/Makefile               |   1 +
 drivers/gpu/drm/panel/panel-sony-acx565akm.c | 701 +++++++++++++++++++
 3 files changed, 710 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-sony-acx565akm.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 8d9a8cdb704e..b05649b3118a 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -316,6 +316,14 @@ config DRM_PANEL_SITRONIX_ST7789V
 	  Say Y here if you want to enable support for the Sitronix
 	  ST7789V controller for 240x320 LCD panels
 
+config DRM_PANEL_SONY_ACX565AKM
+	tristate "Sony ACX565AKM panel"
+	depends on GPIOLIB && OF && SPI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for the Sony ACX565AKM
+	  800x600 3.5" panel (found on the Nokia N900).
+
 config DRM_PANEL_TPO_TPG110
 	tristate "TPO TPG 800x400 panel"
 	depends on OF && SPI && GPIOLIB
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 14d1c49ef3ab..28cf2332fd06 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -33,5 +33,6 @@ obj-$(CONFIG_DRM_PANEL_SHARP_LS037V7DW01) += panel-sharp-ls037v7dw01.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7701) += panel-sitronix-st7701.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
+obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
 obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o
 obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o
diff --git a/drivers/gpu/drm/panel/panel-sony-acx565akm.c b/drivers/gpu/drm/panel/panel-sony-acx565akm.c
new file mode 100644
index 000000000000..28d900d60f2d
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-sony-acx565akm.c
@@ -0,0 +1,701 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sony ACX565AKM LCD Panel driver
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated
+ *
+ * Based on the omapdrm-specific panel-sony-acx565akm driver
+ *
+ * Copyright (C) 2010 Nokia Corporation
+ * Author: Imre Deak <imre.deak@nokia.com>
+ */
+
+/*
+ * TODO (to be addressed with hardware access to test the changes):
+ *
+ * - Update backlight support to use backlight_update_status() etc.
+ * - Use prepare/unprepare for the basic power on/off of the backligt
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/spi/spi.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+#define CTRL_DISP_BRIGHTNESS_CTRL_ON		(1 << 5)
+#define CTRL_DISP_AMBIENT_LIGHT_CTRL_ON		(1 << 4)
+#define CTRL_DISP_BACKLIGHT_ON			(1 << 2)
+#define CTRL_DISP_AUTO_BRIGHTNESS_ON		(1 << 1)
+
+#define MIPID_CMD_WRITE_CABC		0x55
+#define MIPID_CMD_READ_CABC		0x56
+
+#define MIPID_VER_LPH8923		3
+#define MIPID_VER_LS041Y3		4
+#define MIPID_VER_L4F00311		8
+#define MIPID_VER_ACX565AKM		9
+
+struct acx565akm_panel {
+	struct drm_panel panel;
+
+	struct spi_device *spi;
+	struct gpio_desc *reset_gpio;
+	struct backlight_device *backlight;
+
+	struct mutex mutex;
+
+	const char *name;
+	u8 display_id[3];
+	int model;
+	int revision;
+	bool has_bc;
+	bool has_cabc;
+
+	bool enabled;
+	unsigned int cabc_mode;
+	/*
+	 * Next value of jiffies when we can issue the next sleep in/out
+	 * command.
+	 */
+	unsigned long hw_guard_end;
+	unsigned long hw_guard_wait;		/* max guard time in jiffies */
+};
+
+#define to_acx565akm_device(p) container_of(p, struct acx565akm_panel, panel)
+
+static void acx565akm_transfer(struct acx565akm_panel *lcd, int cmd,
+			      const u8 *wbuf, int wlen, u8 *rbuf, int rlen)
+{
+	struct spi_message	m;
+	struct spi_transfer	*x, xfer[5];
+	int			ret;
+
+	spi_message_init(&m);
+
+	memset(xfer, 0, sizeof(xfer));
+	x = &xfer[0];
+
+	cmd &=  0xff;
+	x->tx_buf = &cmd;
+	x->bits_per_word = 9;
+	x->len = 2;
+
+	if (rlen > 1 && wlen == 0) {
+		/*
+		 * Between the command and the response data there is a
+		 * dummy clock cycle. Add an extra bit after the command
+		 * word to account for this.
+		 */
+		x->bits_per_word = 10;
+		cmd <<= 1;
+	}
+	spi_message_add_tail(x, &m);
+
+	if (wlen) {
+		x++;
+		x->tx_buf = wbuf;
+		x->len = wlen;
+		x->bits_per_word = 9;
+		spi_message_add_tail(x, &m);
+	}
+
+	if (rlen) {
+		x++;
+		x->rx_buf	= rbuf;
+		x->len		= rlen;
+		spi_message_add_tail(x, &m);
+	}
+
+	ret = spi_sync(lcd->spi, &m);
+	if (ret < 0)
+		dev_dbg(&lcd->spi->dev, "spi_sync %d\n", ret);
+}
+
+static inline void acx565akm_cmd(struct acx565akm_panel *lcd, int cmd)
+{
+	acx565akm_transfer(lcd, cmd, NULL, 0, NULL, 0);
+}
+
+static inline void acx565akm_write(struct acx565akm_panel *lcd,
+			       int reg, const u8 *buf, int len)
+{
+	acx565akm_transfer(lcd, reg, buf, len, NULL, 0);
+}
+
+static inline void acx565akm_read(struct acx565akm_panel *lcd,
+			      int reg, u8 *buf, int len)
+{
+	acx565akm_transfer(lcd, reg, NULL, 0, buf, len);
+}
+
+/* -----------------------------------------------------------------------------
+ * Auto Brightness Control Via sysfs
+ */
+
+static unsigned int acx565akm_get_cabc_mode(struct acx565akm_panel *lcd)
+{
+	return lcd->cabc_mode;
+}
+
+static void acx565akm_set_cabc_mode(struct acx565akm_panel *lcd,
+				    unsigned int mode)
+{
+	u16 cabc_ctrl;
+
+	lcd->cabc_mode = mode;
+	if (!lcd->enabled)
+		return;
+	cabc_ctrl = 0;
+	acx565akm_read(lcd, MIPID_CMD_READ_CABC, (u8 *)&cabc_ctrl, 1);
+	cabc_ctrl &= ~3;
+	cabc_ctrl |= (1 << 8) | (mode & 3);
+	acx565akm_write(lcd, MIPID_CMD_WRITE_CABC, (u8 *)&cabc_ctrl, 2);
+}
+
+static unsigned int acx565akm_get_hw_cabc_mode(struct acx565akm_panel *lcd)
+{
+	u8 cabc_ctrl;
+
+	acx565akm_read(lcd, MIPID_CMD_READ_CABC, &cabc_ctrl, 1);
+	return cabc_ctrl & 3;
+}
+
+static const char * const acx565akm_cabc_modes[] = {
+	"off",		/* always used when CABC is not supported */
+	"ui",
+	"still-image",
+	"moving-image",
+};
+
+static ssize_t cabc_mode_show(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	struct acx565akm_panel *lcd = dev_get_drvdata(dev);
+	const char *mode_str;
+	int mode;
+
+	if (!lcd->has_cabc)
+		mode = 0;
+	else
+		mode = acx565akm_get_cabc_mode(lcd);
+
+	mode_str = "unknown";
+	if (mode >= 0 && mode < ARRAY_SIZE(acx565akm_cabc_modes))
+		mode_str = acx565akm_cabc_modes[mode];
+
+	return sprintf(buf, "%s\n", mode_str);
+}
+
+static ssize_t cabc_mode_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct acx565akm_panel *lcd = dev_get_drvdata(dev);
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(acx565akm_cabc_modes); i++) {
+		const char *mode_str = acx565akm_cabc_modes[i];
+		int cmp_len = strlen(mode_str);
+
+		if (count > 0 && buf[count - 1] == '\n')
+			count--;
+		if (count != cmp_len)
+			continue;
+
+		if (strncmp(buf, mode_str, cmp_len) == 0)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(acx565akm_cabc_modes))
+		return -EINVAL;
+
+	if (!lcd->has_cabc && i != 0)
+		return -EINVAL;
+
+	mutex_lock(&lcd->mutex);
+	acx565akm_set_cabc_mode(lcd, i);
+	mutex_unlock(&lcd->mutex);
+
+	return count;
+}
+
+static ssize_t cabc_available_modes_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct acx565akm_panel *lcd = dev_get_drvdata(dev);
+	unsigned int i;
+	size_t len = 0;
+
+	if (!lcd->has_cabc)
+		return sprintf(buf, "%s\n", acx565akm_cabc_modes[0]);
+
+	for (i = 0; i < ARRAY_SIZE(acx565akm_cabc_modes); i++)
+		len += sprintf(&buf[len], "%s%s", i ? " " : "",
+			       acx565akm_cabc_modes[i]);
+
+	buf[len++] = '\n';
+
+	return len;
+}
+
+static DEVICE_ATTR_RW(cabc_mode);
+static DEVICE_ATTR_RO(cabc_available_modes);
+
+static struct attribute *acx565akm_cabc_attrs[] = {
+	&dev_attr_cabc_mode.attr,
+	&dev_attr_cabc_available_modes.attr,
+	NULL,
+};
+
+static const struct attribute_group acx565akm_cabc_attr_group = {
+	.attrs = acx565akm_cabc_attrs,
+};
+
+/* -----------------------------------------------------------------------------
+ * Backlight Device
+ */
+
+static int acx565akm_get_actual_brightness(struct acx565akm_panel *lcd)
+{
+	u8 bv;
+
+	acx565akm_read(lcd, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, &bv, 1);
+
+	return bv;
+}
+
+static void acx565akm_set_brightness(struct acx565akm_panel *lcd, int level)
+{
+	u16 ctrl;
+	int bv;
+
+	bv = level | (1 << 8);
+	acx565akm_write(lcd, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, (u8 *)&bv, 2);
+
+	acx565akm_read(lcd, MIPI_DCS_GET_CONTROL_DISPLAY, (u8 *)&ctrl, 1);
+	if (level)
+		ctrl |= CTRL_DISP_BRIGHTNESS_CTRL_ON |
+			CTRL_DISP_BACKLIGHT_ON;
+	else
+		ctrl &= ~(CTRL_DISP_BRIGHTNESS_CTRL_ON |
+			  CTRL_DISP_BACKLIGHT_ON);
+
+	ctrl |= 1 << 8;
+	acx565akm_write(lcd, MIPI_DCS_WRITE_CONTROL_DISPLAY, (u8 *)&ctrl, 2);
+}
+
+static int acx565akm_bl_update_status_locked(struct backlight_device *dev)
+{
+	struct acx565akm_panel *lcd = dev_get_drvdata(&dev->dev);
+	int level;
+
+	if (dev->props.fb_blank == FB_BLANK_UNBLANK &&
+	    dev->props.power == FB_BLANK_UNBLANK)
+		level = dev->props.brightness;
+	else
+		level = 0;
+
+	acx565akm_set_brightness(lcd, level);
+
+	return 0;
+}
+
+static int acx565akm_bl_update_status(struct backlight_device *dev)
+{
+	struct acx565akm_panel *lcd = dev_get_drvdata(&dev->dev);
+	int ret;
+
+	mutex_lock(&lcd->mutex);
+	ret = acx565akm_bl_update_status_locked(dev);
+	mutex_unlock(&lcd->mutex);
+
+	return ret;
+}
+
+static int acx565akm_bl_get_intensity(struct backlight_device *dev)
+{
+	struct acx565akm_panel *lcd = dev_get_drvdata(&dev->dev);
+	unsigned int intensity;
+
+	mutex_lock(&lcd->mutex);
+
+	if (dev->props.fb_blank == FB_BLANK_UNBLANK &&
+	    dev->props.power == FB_BLANK_UNBLANK)
+		intensity = acx565akm_get_actual_brightness(lcd);
+	else
+		intensity = 0;
+
+	mutex_unlock(&lcd->mutex);
+
+	return intensity;
+}
+
+static const struct backlight_ops acx565akm_bl_ops = {
+	.get_brightness = acx565akm_bl_get_intensity,
+	.update_status  = acx565akm_bl_update_status,
+};
+
+static int acx565akm_backlight_init(struct acx565akm_panel *lcd)
+{
+	struct backlight_properties props = {
+		.fb_blank = FB_BLANK_UNBLANK,
+		.power = FB_BLANK_UNBLANK,
+		.type = BACKLIGHT_RAW,
+	};
+	int ret;
+
+	lcd->backlight = backlight_device_register(lcd->name, &lcd->spi->dev,
+						   lcd, &acx565akm_bl_ops,
+						   &props);
+	if (IS_ERR(lcd->backlight)) {
+		ret = PTR_ERR(lcd->backlight);
+		lcd->backlight = NULL;
+		return ret;
+	}
+
+	if (lcd->has_cabc) {
+		ret = sysfs_create_group(&lcd->backlight->dev.kobj,
+					 &acx565akm_cabc_attr_group);
+		if (ret < 0) {
+			dev_err(&lcd->spi->dev,
+				"%s failed to create sysfs files\n", __func__);
+			backlight_device_unregister(lcd->backlight);
+			return ret;
+		}
+
+		lcd->cabc_mode = acx565akm_get_hw_cabc_mode(lcd);
+	}
+
+	lcd->backlight->props.max_brightness = 255;
+	lcd->backlight->props.brightness = acx565akm_get_actual_brightness(lcd);
+
+	acx565akm_bl_update_status_locked(lcd->backlight);
+
+	return 0;
+}
+
+static void acx565akm_backlight_cleanup(struct acx565akm_panel *lcd)
+{
+	if (lcd->has_cabc)
+		sysfs_remove_group(&lcd->backlight->dev.kobj,
+				   &acx565akm_cabc_attr_group);
+
+	backlight_device_unregister(lcd->backlight);
+}
+
+/* -----------------------------------------------------------------------------
+ * DRM Bridge Operations
+ */
+
+static void acx565akm_set_sleep_mode(struct acx565akm_panel *lcd, int on)
+{
+	int cmd = on ? MIPI_DCS_ENTER_SLEEP_MODE : MIPI_DCS_EXIT_SLEEP_MODE;
+	unsigned long wait;
+
+	/*
+	 * We have to keep 120msec between sleep in/out commands.
+	 * (8.2.15, 8.2.16).
+	 */
+	wait = lcd->hw_guard_end - jiffies;
+	if ((long)wait > 0 && wait <= lcd->hw_guard_wait) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		schedule_timeout(wait);
+	}
+
+	acx565akm_cmd(lcd, cmd);
+
+	lcd->hw_guard_wait = msecs_to_jiffies(120);
+	lcd->hw_guard_end = jiffies + lcd->hw_guard_wait;
+}
+
+static void acx565akm_set_display_state(struct acx565akm_panel *lcd,
+					int enabled)
+{
+	int cmd = enabled ? MIPI_DCS_SET_DISPLAY_ON : MIPI_DCS_SET_DISPLAY_OFF;
+
+	acx565akm_cmd(lcd, cmd);
+}
+
+static int acx565akm_power_on(struct acx565akm_panel *lcd)
+{
+	/*FIXME tweak me */
+	msleep(50);
+
+	gpiod_set_value(lcd->reset_gpio, 1);
+
+	if (lcd->enabled) {
+		dev_dbg(&lcd->spi->dev, "panel already enabled\n");
+		return 0;
+	}
+
+	/*
+	 * We have to meet all the following delay requirements:
+	 * 1. tRW: reset pulse width 10usec (7.12.1)
+	 * 2. tRT: reset cancel time 5msec (7.12.1)
+	 * 3. Providing PCLK,HS,VS signals for 2 frames = ~50msec worst
+	 *    case (7.6.2)
+	 * 4. 120msec before the sleep out command (7.12.1)
+	 */
+	msleep(120);
+
+	acx565akm_set_sleep_mode(lcd, 0);
+	lcd->enabled = true;
+
+	/* 5msec between sleep out and the next command. (8.2.16) */
+	usleep_range(5000, 10000);
+	acx565akm_set_display_state(lcd, 1);
+	acx565akm_set_cabc_mode(lcd, lcd->cabc_mode);
+
+	return acx565akm_bl_update_status_locked(lcd->backlight);
+}
+
+static void acx565akm_power_off(struct acx565akm_panel *lcd)
+{
+	if (!lcd->enabled)
+		return;
+
+	acx565akm_set_display_state(lcd, 0);
+	acx565akm_set_sleep_mode(lcd, 1);
+	lcd->enabled = false;
+	/*
+	 * We have to provide PCLK,HS,VS signals for 2 frames (worst case
+	 * ~50msec) after sending the sleep in command and asserting the
+	 * reset signal. We probably could assert the reset w/o the delay
+	 * but we still delay to avoid possible artifacts. (7.6.1)
+	 */
+	msleep(50);
+
+	gpiod_set_value(lcd->reset_gpio, 0);
+
+	/* FIXME need to tweak this delay */
+	msleep(100);
+}
+
+static int acx565akm_disable(struct drm_panel *panel)
+{
+	struct acx565akm_panel *lcd = to_acx565akm_device(panel);
+
+	mutex_lock(&lcd->mutex);
+	acx565akm_power_off(lcd);
+	mutex_unlock(&lcd->mutex);
+
+	return 0;
+}
+
+static int acx565akm_enable(struct drm_panel *panel)
+{
+	struct acx565akm_panel *lcd = to_acx565akm_device(panel);
+
+	mutex_lock(&lcd->mutex);
+	acx565akm_power_on(lcd);
+	mutex_unlock(&lcd->mutex);
+
+	return 0;
+}
+
+static const struct drm_display_mode acx565akm_mode = {
+	.clock = 24000,
+	.hdisplay = 800,
+	.hsync_start = 800 + 28,
+	.hsync_end = 800 + 28 + 4,
+	.htotal = 800 + 28 + 4 + 24,
+	.vdisplay = 480,
+	.vsync_start = 480 + 3,
+	.vsync_end = 480 + 3 + 3,
+	.vtotal = 480 + 3 + 3 + 4,
+	.vrefresh = 57,
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.width_mm = 77,
+	.height_mm = 46,
+};
+
+static int acx565akm_get_modes(struct drm_panel *panel)
+{
+	struct drm_connector *connector = panel->connector;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &acx565akm_mode);
+	if (!mode)
+		return -ENOMEM;
+
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+
+	connector->display_info.width_mm = acx565akm_mode.width_mm;
+	connector->display_info.height_mm = acx565akm_mode.height_mm;
+	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
+					  | DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE
+					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs acx565akm_funcs = {
+	.disable = acx565akm_disable,
+	.enable = acx565akm_enable,
+	.get_modes = acx565akm_get_modes,
+};
+
+/* -----------------------------------------------------------------------------
+ * Probe, Detect and Remove
+ */
+
+static int acx565akm_detect(struct acx565akm_panel *lcd)
+{
+	__be32 value;
+	u32 status;
+	int ret = 0;
+
+	/*
+	 * After being taken out of reset the panel needs 5ms before the first
+	 * command can be sent.
+	 */
+	gpiod_set_value(lcd->reset_gpio, 1);
+	usleep_range(5000, 10000);
+
+	acx565akm_read(lcd, MIPI_DCS_GET_DISPLAY_STATUS, (u8 *)&value, 4);
+	status = __be32_to_cpu(value);
+	lcd->enabled = (status & (1 << 17)) && (status & (1 << 10));
+
+	dev_dbg(&lcd->spi->dev,
+		"LCD panel %s by bootloader (status 0x%04x)\n",
+		lcd->enabled ? "enabled" : "disabled ", status);
+
+	acx565akm_read(lcd, MIPI_DCS_GET_DISPLAY_ID, lcd->display_id, 3);
+	dev_dbg(&lcd->spi->dev, "MIPI display ID: %02x%02x%02x\n",
+		lcd->display_id[0], lcd->display_id[1], lcd->display_id[2]);
+
+	switch (lcd->display_id[0]) {
+	case 0x10:
+		lcd->model = MIPID_VER_ACX565AKM;
+		lcd->name = "acx565akm";
+		lcd->has_bc = 1;
+		lcd->has_cabc = 1;
+		break;
+	case 0x29:
+		lcd->model = MIPID_VER_L4F00311;
+		lcd->name = "l4f00311";
+		break;
+	case 0x45:
+		lcd->model = MIPID_VER_LPH8923;
+		lcd->name = "lph8923";
+		break;
+	case 0x83:
+		lcd->model = MIPID_VER_LS041Y3;
+		lcd->name = "ls041y3";
+		break;
+	default:
+		lcd->name = "unknown";
+		dev_err(&lcd->spi->dev, "unknown display ID\n");
+		ret = -ENODEV;
+		goto done;
+	}
+
+	lcd->revision = lcd->display_id[1];
+
+	dev_info(&lcd->spi->dev, "%s rev %02x panel detected\n",
+		 lcd->name, lcd->revision);
+
+done:
+	if (!lcd->enabled)
+		gpiod_set_value(lcd->reset_gpio, 0);
+
+	return ret;
+}
+
+static int acx565akm_probe(struct spi_device *spi)
+{
+	struct acx565akm_panel *lcd;
+	int ret;
+
+	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
+	if (lcd == NULL)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, lcd);
+	spi->mode = SPI_MODE_3;
+
+	lcd->spi = spi;
+	mutex_init(&lcd->mutex);
+
+	lcd->reset_gpio = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->reset_gpio)) {
+		dev_err(&spi->dev, "failed to get reset GPIO\n");
+		return PTR_ERR(lcd->reset_gpio);
+	}
+
+	ret = acx565akm_detect(lcd);
+	if (ret < 0) {
+		dev_err(&spi->dev, "panel detection failed\n");
+		return ret;
+	}
+
+	if (lcd->has_bc) {
+		ret = acx565akm_backlight_init(lcd);
+		if (ret < 0)
+			return ret;
+	}
+
+	drm_panel_init(&lcd->panel);
+	lcd->panel.dev = &lcd->spi->dev;
+	lcd->panel.funcs = &acx565akm_funcs;
+
+	ret = drm_panel_add(&lcd->panel);
+	if (ret < 0) {
+		if (lcd->has_bc)
+			acx565akm_backlight_cleanup(lcd);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int acx565akm_remove(struct spi_device *spi)
+{
+	struct acx565akm_panel *lcd = spi_get_drvdata(spi);
+
+	drm_panel_remove(&lcd->panel);
+
+	if (lcd->has_bc)
+		acx565akm_backlight_cleanup(lcd);
+
+	drm_panel_disable(&lcd->panel);
+	drm_panel_unprepare(&lcd->panel);
+
+	return 0;
+}
+
+static const struct of_device_id acx565akm_of_match[] = {
+	{ .compatible = "sony,acx565akm", },
+	{ /* sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, acx565akm_of_match);
+
+static struct spi_driver acx565akm_driver = {
+	.probe		= acx565akm_probe,
+	.remove		= acx565akm_remove,
+	.driver		= {
+		.name	= "panel-sony-acx565akm",
+		.of_match_table = acx565akm_of_match,
+	},
+};
+
+module_spi_driver(acx565akm_driver);
+
+MODULE_ALIAS("spi:sony,acx565akm");
+MODULE_AUTHOR("Nokia Corporation");
+MODULE_DESCRIPTION("Sony ACX565AKM LCD Panel Driver");
+MODULE_LICENSE("GPL");