--- /dev/null
+// 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");