[PATCH v5 3/6] drm: Add driver for Solomon SSD130x OLED displays

Javier Martinez Canillas
2022-02-11T14:34:28Z

This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
OLED display controllers.

It's only the core part of the driver and a bus specific driver is needed
for each transport interface supported by the display controllers.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

Changes in v5:
- Include <linux/bits.h> header (Andy Shevchenko)
- Drop parenthesis for command options macros (Andy Shevchenko)
- Explain in ssd130x_write_cmd() comment how commands are sent (Andy Shevchenko)
- The pwm_*() functions check for NULL already (Andy Shevchenko)
- Remove unnecesary blank line (Andy Shevchenko)
- Simplify error handling for backlight registration failure (Geert Uytterhoeven)
- Don't clear screen on enable, instead send the full buffer (Thomas Zimmermann)

Changes in v4:
- Rename vbat supply to vcc since is how's labeled in the device (Mark Brown)
- Don't make the regulator option since is always needed (Mark Brown)
- Add solomon Kconfig source and directory inclusion sorted (Andy Shevchenko)
- Use SSD130x instead of SSD130X to denote is not a model name (Andy Shevchenko)
- Check if there's a reset pin in the callee and not the caller (Andy Shevchenko)
- Define missing commands instead of using magic numbers (Andy Shevchenko)
- Use GENMASK() and FIELD_PREP() macros when possible (Andy Shevchenko)
- Avoid using ternary operators to ease code readablity (Andy Shevchenko)
- Use i++ instead of --i on some for loops (Andy Shevchenko)
- Remove redundant blank lines (Andy Shevchenko)
- Rename power_off label to out_power_off (Andy Shevchenko)
- Use dev_err_probe() even if no -EPROBE_DEFER (Andy Shevchenko)
- Don't use plural Authors if there's only one (Andy Shevchenko)

Changes in v3:
- Move driver from tiny sub-dir to drivers/gpu/drm/solomon (Sam Ravnborg)
- Split driver in a bus agnostic core and bus specific (Andy Shevchenko)
- Use regmap to access the chip registers (Andy Shevchenko)
- Remove unnecessary blank lines (Andy Shevchenko)
- Remove unneeded inline specifier in functions (Andy Shevchenko)
- Add a comment about always returning a single mode (Andy Shevchenko)
- Change write command logic to use do while loop (Andy Shevchenko)
- Use "firmware description" instead of "device tree" (Andy Shevchenko)
- Use return foo() instead of returning the return value (Andy Shevchenko)
- Don't split lines longer than 80 chars if makes less readable (Andy Shevchenko)
- Remove redundant else statements in .mode_valid callback (Andy Shevchenko)
- Rename powero{n,ff}() functions to power_o{n,ff)() (Andy Shevchenko)
- Use dev_err_probe() to prevent spam logs on probe deferral (Andy Shevchenko)
- Remove ',' after sentinel terminator in array (Andy Shevchenko)
- Fix a bug when doing partial updates (Geert Uytterhoeven)

Changes in v2:
- Drop patch that was adding a DRM_MODE_CONNECTOR_I2C type.
- Invert order of backlight {en,dis}able and display {on,off} (Sam Ravnborg)
- Don't clear the screen and turn on display on probe (Sam Ravnborg)
- Use backlight_get_brightness() macro to get BL brightness (Sam Ravnborg)
- Use dev managed version of devm_backlight_device_register() (Sam Ravnborg)
- Use dev_name(dev) for backlight name instead of an array (Sam Ravnborg)
- Drop the .get_brightness callback since isn't needed (Sam Ravnborg)
- Rename driver to ssd130x since supports a display family (Thomas Zimmermann)
- Drop the TINY prefix from the Kconfig symbol (Thomas Zimmermann)
- Sort the Kconfig symbol dependencies alphabetically (Thomas Zimmermann)
- Rename struct ssd130x_array to struct ssd130x_i2c_msg (Thomas Zimmermann)
- Rename struct ssd130x_i2c_msg .type member to .cmd (Thomas Zimmermann)
- Use sizeof(*foo) instead of sizeof(struct foo) (Thomas Zimmermann)
- Use struct_size() macro to calculate sizeof(*foo) + len (Thomas Zimmermann)
- Use kcalloc() instead of kmalloc_array() + memset() (Thomas Zimmermann)
- Use shadow plane helpers virtual screen support (Thomas Zimmermann)
- Remove unused goto label in ssd1307_fb_blit_rect() (Thomas Zimmermann)
- Use drm_set_preferred_mode() inset of manually set (Thomas Zimmermann)
- Use shadow plane helpers virtual screen support (Thomas Zimmermann)
- Remove unused goto label in ssd1307_fb_blit_rect() (Thomas Zimmermann)
- Use drm_set_preferred_mode() inset of manually set (Thomas Zimmermann)
- Reorganize code in probe to make it more legible (Thomas Zimmermann)
- ssd130x_write_cmd() uses varargs to simplify I2C code (Thomas Zimmermann)
- Move regulator/pwm init logic to display pipe enable callback.

drivers/gpu/drm/Kconfig | 2 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/solomon/Kconfig | 12 +
drivers/gpu/drm/solomon/Makefile | 1 +
drivers/gpu/drm/solomon/ssd130x.c | 851 ++++++++++++++++++++++++++++++
drivers/gpu/drm/solomon/ssd130x.h | 76 +++
6 files changed, 943 insertions(+)
create mode 100644 drivers/gpu/drm/solomon/Kconfig
create mode 100644 drivers/gpu/drm/solomon/Makefile
create mode 100644 drivers/gpu/drm/solomon/ssd130x.c
create mode 100644 drivers/gpu/drm/solomon/ssd130x.h

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index dfdd3ec5f793..763355330b17 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -403,6 +403,8 @@ source "drivers/gpu/drm/xlnx/Kconfig"

source "drivers/gpu/drm/gud/Kconfig"

+source "drivers/gpu/drm/solomon/Kconfig"
+
source "drivers/gpu/drm/sprd/Kconfig"

config DRM_HYPERV
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 8675c2af7ae1..c2ef5f9fce54 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -132,4 +132,5 @@ obj-$(CONFIG_DRM_TIDSS) += tidss/
obj-y += xlnx/
obj-y += gud/
obj-$(CONFIG_DRM_HYPERV) += hyperv/
+obj-y += solomon/
obj-$(CONFIG_DRM_SPRD) += sprd/
diff --git a/drivers/gpu/drm/solomon/Kconfig b/drivers/gpu/drm/solomon/Kconfig
new file mode 100644
index 000000000000..7720a7039e8d
--- /dev/null
+++ b/drivers/gpu/drm/solomon/Kconfig
@@ -0,0 +1,12 @@
+config DRM_SSD130X
+ tristate "DRM support for Solomon SSD130x OLED displays"
+ depends on DRM
+ select BACKLIGHT_CLASS_DEVICE
+ select DRM_GEM_SHMEM_HELPER
+ select DRM_KMS_HELPER
+ help
+ DRM driver for the SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
+ OLED controllers. This is only for the core driver, a driver for
+ the appropriate bus transport in your chip also must be selected.
+
+ If M is selected the module will be called ssd130x.
diff --git a/drivers/gpu/drm/solomon/Makefile b/drivers/gpu/drm/solomon/Makefile
new file mode 100644
index 000000000000..f685addb19fe
--- /dev/null
+++ b/drivers/gpu/drm/solomon/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_DRM_SSD130X) += ssd130x.o
diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
new file mode 100644
index 000000000000..c7377dcc82e2
--- /dev/null
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -0,0 +1,851 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * DRM driver for Solomon SSD130x OLED displays
+ *
+ * Copyright 2022 Red Hat Inc.
+ * Author: Javier Martinez Canillas <javierm@redhat.com>
+ *
+ * Based on drivers/video/fbdev/ssd1307fb.c
+ * Copyright 2012 Free Electrons
+ */
+
+#include <linux/backlight.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/property.h>
+#include <linux/pwm.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_rect.h>
+#include <drm/drm_probe_helper.h>
+
+#include "ssd130x.h"
+
+#define DRIVER_NAME "ssd130x"
+#define DRIVER_DESC "DRM driver for Solomon SSD130x OLED displays"
+#define DRIVER_DATE "20220131"
+#define DRIVER_MAJOR 1
+#define DRIVER_MINOR 0
+
+#define SSD130X_DATA 0x40
+#define SSD130X_COMMAND 0x80
+
+#define SSD130X_SET_ADDRESS_MODE 0x20
+#define SSD130X_SET_COL_RANGE 0x21
+#define SSD130X_SET_PAGE_RANGE 0x22
+#define SSD130X_CONTRAST 0x81
+#define SSD130X_SET_LOOKUP_TABLE 0x91
+#define SSD130X_CHARGE_PUMP 0x8d
+#define SSD130X_SEG_REMAP_ON 0xa1
+#define SSD130X_DISPLAY_OFF 0xae
+#define SSD130X_SET_MULTIPLEX_RATIO 0xa8
+#define SSD130X_DISPLAY_ON 0xaf
+#define SSD130X_START_PAGE_ADDRESS 0xb0
+#define SSD130X_SET_COM_SCAN_DIR 0xc0
+#define SSD130X_SET_DISPLAY_OFFSET 0xd3
+#define SSD130X_SET_CLOCK_FREQ 0xd5
+#define SSD130X_SET_AREA_COLOR_MODE 0xd8
+#define SSD130X_SET_PRECHARGE_PERIOD 0xd9
+#define SSD130X_SET_COM_PINS_CONFIG 0xda
+#define SSD130X_SET_VCOMH 0xdb
+
+#define SSD130X_SET_COM_SCAN_DIR_MASK GENMASK(3, 2)
+#define SSD130X_SET_COM_SCAN_DIR_SET(val) FIELD_PREP(SSD130X_SET_COM_SCAN_DIR_MASK, (val))
+#define SSD130X_SET_CLOCK_DIV_MASK GENMASK(3, 0)
+#define SSD130X_SET_CLOCK_DIV_SET(val) FIELD_PREP(SSD130X_SET_CLOCK_DIV_MASK, (val))
+#define SSD130X_SET_CLOCK_FREQ_MASK GENMASK(7, 4)
+#define SSD130X_SET_CLOCK_FREQ_SET(val) FIELD_PREP(SSD130X_SET_CLOCK_FREQ_MASK, (val))
+#define SSD130X_SET_PRECHARGE_PERIOD1_MASK GENMASK(3, 0)
+#define SSD130X_SET_PRECHARGE_PERIOD1_SET(val) FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD1_MASK, (val))
+#define SSD130X_SET_PRECHARGE_PERIOD2_MASK GENMASK(7, 4)
+#define SSD130X_SET_PRECHARGE_PERIOD2_SET(val) FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD2_MASK, (val))
+#define SSD130X_SET_COM_PINS_CONFIG1_MASK GENMASK(4, 4)
+#define SSD130X_SET_COM_PINS_CONFIG1_SET(val) FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, (!val))
+#define SSD130X_SET_COM_PINS_CONFIG2_MASK GENMASK(5, 5)
+#define SSD130X_SET_COM_PINS_CONFIG2_SET(val) FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG2_MASK, (val))
+
+#define SSD130X_SET_ADDRESS_MODE_HORIZONTAL 0x00
+#define SSD130X_SET_ADDRESS_MODE_VERTICAL 0x01
+#define SSD130X_SET_ADDRESS_MODE_PAGE 0x02
+
+#define SSD130X_SET_AREA_COLOR_MODE_ENABLE 0x1e
+#define SSD130X_SET_AREA_COLOR_MODE_LOW_POWER 0x05
+
+#define MAX_CONTRAST 255
+
+static inline struct ssd130x_device *drm_to_ssd130x(struct drm_device *drm)
+{
+ return container_of(drm, struct ssd130x_device, drm);
+}
+
+/*
+ * Helper to write data (SSD130X_DATA) to the device.
+ */
+static int ssd130x_write_data(struct ssd130x_device *ssd130x, u8 *values, int count)
+{
+ int ret;
+
+ ret = regmap_bulk_write(ssd130x->regmap, SSD130X_DATA, values, count);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/*
+ * Helper to write command (SSD130X_COMMAND). The fist variadic argument
+ * is the command to write and the following are the command options.
+ *
+ * Note that the ssd130x protocol requires each command and option to be
+ * written as a SSD130X_COMMAND device register value. That is why a call
+ * to regmap_write(..., SSD130X_COMMAND, ...) is done for each argument.
+ */
+static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
+ /* u8 cmd, u8 option, ... */...)
+{
+ va_list ap;
+ u8 value;
+ int ret;
+
+ va_start(ap, count);
+
+ do {
+ value = va_arg(ap, int);
+ ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, (u8)value);
+ if (ret)
+ goto out_end;
+ } while (--count);
+
+out_end:
+ va_end(ap);
+
+ return ret;
+}
+
+static int ssd130x_set_col_range(struct ssd130x_device *ssd130x,
+ u8 col_start, u8 cols)
+{
+ u8 col_end = col_start + cols - 1;
+ int ret;
+
+ if (col_start == ssd130x->col_start && col_end == ssd130x->col_end)
+ return 0;
+
+ ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_COL_RANGE, col_start, col_end);
+ if (ret < 0)
+ return ret;
+
+ ssd130x->col_start = col_start;
+ ssd130x->col_end = col_end;
+ return 0;
+}
+
+static int ssd130x_set_page_range(struct ssd130x_device *ssd130x,
+ u8 page_start, u8 pages)
+{
+ u8 page_end = page_start + pages - 1;
+ int ret;
+
+ if (page_start == ssd130x->page_start && page_end == ssd130x->page_end)
+ return 0;
+
+ ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_PAGE_RANGE, page_start, page_end);
+ if (ret < 0)
+ return ret;
+
+ ssd130x->page_start = page_start;
+ ssd130x->page_end = page_end;
+ return 0;
+}
+
+static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x)
+{
+ struct device *dev = ssd130x->dev;
+ struct pwm_state pwmstate;
+
+ ssd130x->pwm = pwm_get(dev, NULL);
+ if (IS_ERR(ssd130x->pwm)) {
+ dev_err(dev, "Could not get PWM from firmware description!\n");
+ return PTR_ERR(ssd130x->pwm);
+ }
+
+ pwm_init_state(ssd130x->pwm, &pwmstate);
+ pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
+ pwm_apply_state(ssd130x->pwm, &pwmstate);
+
+ /* Enable the PWM */
+ pwm_enable(ssd130x->pwm);
+
+ dev_dbg(dev, "Using PWM%d with a %lluns period.\n",
+ ssd130x->pwm->pwm, pwm_get_period(ssd130x->pwm));
+
+ return 0;
+}
+
+static void ssd130x_reset(struct ssd130x_device *ssd130x)
+{
+ if (!ssd130x->reset)
+ return;
+
+ /* Reset the screen */
+ gpiod_set_value_cansleep(ssd130x->reset, 1);
+ udelay(4);
+ gpiod_set_value_cansleep(ssd130x->reset, 0);
+ udelay(4);
+}
+
+static int ssd130x_power_on(struct ssd130x_device *ssd130x)
+{
+ struct device *dev = ssd130x->dev;
+ int ret;
+
+ ssd130x_reset(ssd130x);
+
+ ret = regulator_enable(ssd130x->vcc_reg);
+ if (ret) {
+ dev_err(dev, "Failed to enable VCC: %d\n", ret);
+ return ret;
+ }
+
+ if (ssd130x->device_info->need_pwm) {
+ ret = ssd130x_pwm_enable(ssd130x);
+ if (ret) {
+ dev_err(dev, "Failed to enable PWM: %d\n", ret);
+ regulator_disable(ssd130x->vcc_reg);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static void ssd130x_power_off(struct ssd130x_device *ssd130x)
+{
+ pwm_disable(ssd130x->pwm);
+ pwm_put(ssd130x->pwm);
+
+ regulator_disable(ssd130x->vcc_reg);
+}
+
+static int ssd130x_init(struct ssd130x_device *ssd130x)
+{
+ u32 precharge, dclk, com_invdir, compins, chargepump;
+ int ret;
+
+ /* Set initial contrast */
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CONTRAST, ssd130x->contrast);
+ if (ret < 0)
+ return ret;
+
+ /* Set segment re-map */
+ if (ssd130x->seg_remap) {
+ ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SEG_REMAP_ON);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* Set COM direction */
+ com_invdir = (SSD130X_SET_COM_SCAN_DIR |
+ SSD130X_SET_COM_SCAN_DIR_SET(ssd130x->com_invdir));
+ ret = ssd130x_write_cmd(ssd130x, 1, com_invdir);
+ if (ret < 0)
+ return ret;
+
+ /* Set multiplex ratio value */
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_MULTIPLEX_RATIO, ssd130x->height - 1);
+ if (ret < 0)
+ return ret;
+
+ /* set display offset value */
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_DISPLAY_OFFSET, ssd130x->com_offset);
+ if (ret < 0)
+ return ret;
+
+ /* Set clock frequency */
+ dclk = (SSD130X_SET_CLOCK_DIV_SET(ssd130x->dclk_div - 1) |
+ SSD130X_SET_CLOCK_FREQ_SET(ssd130x->dclk_frq));
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_CLOCK_FREQ, dclk);
+ if (ret < 0)
+ return ret;
+
+ /* Set Area Color Mode ON/OFF & Low Power Display Mode */
+ if (ssd130x->area_color_enable || ssd130x->low_power) {
+ u32 mode = 0;
+
+ if (ssd130x->area_color_enable)
+ mode |= SSD130X_SET_AREA_COLOR_MODE_ENABLE;
+
+ if (ssd130x->low_power)
+ mode |= SSD130X_SET_AREA_COLOR_MODE_LOW_POWER;
+
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_AREA_COLOR_MODE, mode);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* Set precharge period in number of ticks from the internal clock */
+ precharge = (SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep1) |
+ SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep2));
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_PRECHARGE_PERIOD, precharge);
+ if (ret < 0)
+ return ret;
+
+ /* Set COM pins configuration */
+ compins = BIT(1);
+ compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(ssd130x->com_seq) |
+ SSD130X_SET_COM_PINS_CONFIG2_SET(ssd130x->com_lrremap));
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
+ if (ret < 0)
+ return ret;
+
+ /* Set VCOMH */
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_VCOMH, ssd130x->vcomh);
+ if (ret < 0)
+ return ret;
+
+ /* Turn on the DC-DC Charge Pump */
+ chargepump = BIT(4);
+
+ if (ssd130x->device_info->need_chargepump)
+ chargepump |= BIT(2);
+
+ ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CHARGE_PUMP, chargepump);
+ if (ret < 0)
+ return ret;
+
+ /* Set lookup table */
+ if (ssd130x->lookup_table_set) {
+ int i;
+
+ ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SET_LOOKUP_TABLE);
+ if (ret < 0)
+ return ret;
+
+ for (i = 0; i < ARRAY_SIZE(ssd130x->lookup_table); i++) {
+ u8 val = ssd130x->lookup_table[i];
+
+ if (val < 31 || val > 63)
+ dev_warn(ssd130x->dev,
+ "lookup table index %d value out of range 31 <= %d <= 63\n",
+ i, val);
+ ret = ssd130x_write_cmd(ssd130x, 1, val);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ /* Switch to horizontal addressing mode */
+ return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
+ SSD130X_SET_ADDRESS_MODE_HORIZONTAL);
+}
+
+static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf,
+ struct drm_rect *rect)
+{
+ unsigned int x = rect->x1;
+ unsigned int y = rect->y1;
+ unsigned int width = drm_rect_width(rect);
+ unsigned int height = drm_rect_height(rect);
+ unsigned int line_length = DIV_ROUND_UP(width, 8);
+ unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8);
+ u32 array_idx = 0;
+ int ret, i, j, k;
+ u8 *data_array = NULL;
+
+ data_array = kcalloc(width, pages, GFP_KERNEL);
+ if (!data_array)
+ return -ENOMEM;
+
+ /*
+ * The screen is divided in pages, each having a height of 8
+ * pixels, and the width of the screen. When sending a byte of
+ * data to the controller, it gives the 8 bits for the current
+ * column. I.e, the first byte are the 8 bits of the first
+ * column, then the 8 bits for the second column, etc.
+ *
+ *
+ * Representation of the screen, assuming it is 5 bits
+ * wide. Each letter-number combination is a bit that controls
+ * one pixel.
+ *
+ * A0 A1 A2 A3 A4
+ * B0 B1 B2 B3 B4
+ * C0 C1 C2 C3 C4
+ * D0 D1 D2 D3 D4
+ * E0 E1 E2 E3 E4
+ * F0 F1 F2 F3 F4
+ * G0 G1 G2 G3 G4
+ * H0 H1 H2 H3 H4
+ *
+ * If you want to update this screen, you need to send 5 bytes:
+ * (1) A0 B0 C0 D0 E0 F0 G0 H0
+ * (2) A1 B1 C1 D1 E1 F1 G1 H1
+ * (3) A2 B2 C2 D2 E2 F2 G2 H2
+ * (4) A3 B3 C3 D3 E3 F3 G3 H3
+ * (5) A4 B4 C4 D4 E4 F4 G4 H4
+ */
+
+ ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset + x, width);
+ if (ret < 0)
+ goto out_free;
+
+ ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset + y / 8, pages);
+ if (ret < 0)
+ goto out_free;
+
+ for (i = y / 8; i < y / 8 + pages; i++) {
+ int m = 8;
+
+ /* Last page may be partial */
+ if (8 * (i + 1) > ssd130x->height)
+ m = ssd130x->height % 8;
+ for (j = x; j < x + width; j++) {
+ u8 data = 0;
+
+ for (k = 0; k < m; k++) {
+ u8 byte = buf[(8 * i + k) * line_length + j / 8];
+ u8 bit = (byte >> (j % 8)) & 1;
+
+ data |= bit << k;
+ }
+ data_array[array_idx++] = data;
+ }
+ }
+
+ ret = ssd130x_write_data(ssd130x, data_array, width * pages);
+
+out_free:
+ kfree(data_array);
+ return ret;
+}
+
+static void ssd130x_clear_screen(struct ssd130x_device *ssd130x)
+{
+ u8 *buf = NULL;
+ struct drm_rect fullscreen = {
+ .x1 = 0,
+ .x2 = ssd130x->width,
+ .y1 = 0,
+ .y2 = ssd130x->height,
+ };
+
+ buf = kcalloc(ssd130x->width, ssd130x->height, GFP_KERNEL);
+ if (!buf)
+ return;
+
+ ssd130x_update_rect(ssd130x, buf, &fullscreen);
+
+ kfree(buf);
+}
+
+static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct dma_buf_map *map,
+ struct drm_rect *rect)
+{
+ struct ssd130x_device *ssd130x = drm_to_ssd130x(fb->dev);
+ void *vmap = map->vaddr; /* TODO: Use mapping abstraction properly */
+ int ret = 0;
+ u8 *buf = NULL;
+
+ buf = kcalloc(fb->width, fb->height, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ drm_fb_xrgb8888_to_mono_reversed(buf, 0, vmap, fb, rect);
+
+ ssd130x_update_rect(ssd130x, buf, rect);
+
+ kfree(buf);
+
+ return ret;
+}
+
+static int ssd130x_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
+ const struct drm_display_mode *mode)
+{
+ struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+
+ if (mode->hdisplay != ssd130x->mode.hdisplay &&
+ mode->vdisplay != ssd130x->mode.vdisplay)
+ return MODE_ONE_SIZE;
+
+ if (mode->hdisplay != ssd130x->mode.hdisplay)
+ return MODE_ONE_WIDTH;
+
+ if (mode->vdisplay != ssd130x->mode.vdisplay)
+ return MODE_ONE_HEIGHT;
+
+ return MODE_OK;
+}
+
+static void ssd130x_display_pipe_enable(struct drm_simple_display_pipe *pipe,
+ struct drm_crtc_state *crtc_state,
+ struct drm_plane_state *plane_state)
+{
+ struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+ struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+ struct drm_device *drm = &ssd130x->drm;
+ int idx, ret;
+
+ ret = ssd130x_power_on(ssd130x);
+ if (ret)
+ return;
+
+ ret = ssd130x_init(ssd130x);
+ if (ret)
+ goto out_power_off;
+
+ if (!drm_dev_enter(drm, &idx))
+ goto out_power_off;
+
+ ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &plane_state->dst);
+
+ ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_ON);
+
+ backlight_enable(ssd130x->bl_dev);
+
+ drm_dev_exit(idx);
+
+ return;
+out_power_off:
+ ssd130x_power_off(ssd130x);
+}
+
+static void ssd130x_display_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+ struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+ struct drm_device *drm = &ssd130x->drm;
+ int idx;
+
+ if (!drm_dev_enter(drm, &idx))
+ return;
+
+ ssd130x_clear_screen(ssd130x);
+
+ backlight_disable(ssd130x->bl_dev);
+
+ ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_OFF);
+
+ ssd130x_power_off(ssd130x);
+
+ drm_dev_exit(idx);
+}
+
+static void ssd130x_display_pipe_update(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *old_plane_state)
+{
+ struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
+ struct drm_plane_state *plane_state = pipe->plane.state;
+ struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+ struct drm_framebuffer *fb = plane_state->fb;
+ struct drm_device *drm = &ssd130x->drm;
+ struct drm_rect src_clip, dst_clip;
+ int idx;
+
+ if (!fb)
+ return;
+
+ if (!pipe->crtc.state->active)
+ return;
+
+ if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &src_clip))
+ return;
+
+ dst_clip = plane_state->dst;
+ if (!drm_rect_intersect(&dst_clip, &src_clip))
+ return;
+
+ if (!drm_dev_enter(drm, &idx))
+ return;
+
+ ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
+
+ drm_dev_exit(idx);
+}
+
+static const struct drm_simple_display_pipe_funcs ssd130x_pipe_funcs = {
+ .mode_valid = ssd130x_display_pipe_mode_valid,
+ .enable = ssd130x_display_pipe_enable,
+ .disable = ssd130x_display_pipe_disable,
+ .update = ssd130x_display_pipe_update,
+ DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
+};
+
+static int ssd130x_connector_get_modes(struct drm_connector *connector)
+{
+ struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev);
+ struct drm_display_mode *mode = &ssd130x->mode;
+ struct device *dev = ssd130x->dev;
+
+ mode = drm_mode_duplicate(connector->dev, &ssd130x->mode);
+ if (!mode) {
+ dev_err(dev, "Failed to duplicated mode\n");
+ return 0;
+ }
+
+ drm_mode_probed_add(connector, mode);
+ drm_set_preferred_mode(connector, mode->hdisplay, mode->vdisplay);
+
+ /* There is only a single mode */
+ return 1;
+}
+
+static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = {
+ .get_modes = ssd130x_connector_get_modes,
+};
+
+static const struct drm_connector_funcs ssd130x_connector_funcs = {
+ .reset = drm_atomic_helper_connector_reset,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = drm_connector_cleanup,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = {
+ .fb_create = drm_gem_fb_create_with_dirty,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+static const uint32_t ssd130x_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+DEFINE_DRM_GEM_FOPS(ssd130x_fops);
+
+static const struct drm_driver ssd130x_drm_driver = {
+ DRM_GEM_SHMEM_DRIVER_OPS,
+ .name = DRIVER_NAME,
+ .desc = DRIVER_DESC,
+ .date = DRIVER_DATE,
+ .major = DRIVER_MAJOR,
+ .minor = DRIVER_MINOR,
+ .driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
+ .fops = &ssd130x_fops,
+};
+
+static int ssd130x_update_bl(struct backlight_device *bdev)
+{
+ struct ssd130x_device *ssd130x = bl_get_data(bdev);
+ int brightness = backlight_get_brightness(bdev);
+ int ret;
+
+ ssd130x->contrast = brightness;
+
+ ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_CONTRAST);
+ if (ret < 0)
+ return ret;
+
+ ret = ssd130x_write_cmd(ssd130x, 1, ssd130x->contrast);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static const struct backlight_ops ssd130xfb_bl_ops = {
+ .update_status = ssd130x_update_bl,
+};
+
+static void ssd130x_parse_properties(struct ssd130x_device *ssd130x)
+{
+ struct device *dev = ssd130x->dev;
+
+ if (device_property_read_u32(dev, "solomon,width", &ssd130x->width))
+ ssd130x->width = 96;
+
+ if (device_property_read_u32(dev, "solomon,height", &ssd130x->height))
+ ssd130x->height = 16;
+
+ if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset))
+ ssd130x->page_offset = 1;
+
+ if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset))
+ ssd130x->col_offset = 0;
+
+ if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset))
+ ssd130x->com_offset = 0;
+
+ if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1))
+ ssd130x->prechargep1 = 2;
+
+ if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2))
+ ssd130x->prechargep2 = 2;
+
+ if (!device_property_read_u8_array(dev, "solomon,lookup-table",
+ ssd130x->lookup_table,
+ ARRAY_SIZE(ssd130x->lookup_table)))
+ ssd130x->lookup_table_set = 1;
+
+ ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
+ ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq");
+ ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
+ ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
+ ssd130x->area_color_enable =
+ device_property_read_bool(dev, "solomon,area-color-enable");
+ ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power");
+
+ ssd130x->contrast = 127;
+ ssd130x->vcomh = ssd130x->device_info->default_vcomh;
+
+ /* Setup display timing */
+ if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div))
+ ssd130x->dclk_div = ssd130x->device_info->default_dclk_div;
+ if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq))
+ ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq;
+}
+
+static int ssd130x_init_modeset(struct ssd130x_device *ssd130x)
+{
+ struct drm_display_mode *mode = &ssd130x->mode;
+ struct device *dev = ssd130x->dev;
+ struct drm_device *drm = &ssd130x->drm;
+ unsigned long max_width, max_height;
+ int ret;
+
+ ret = drmm_mode_config_init(drm);
+ if (ret) {
+ dev_err(dev, "DRM mode config init failed: %d\n", ret);
+ return ret;
+ }
+
+ mode->type = DRM_MODE_TYPE_DRIVER;
+ mode->clock = 1;
+ mode->hdisplay = mode->htotal = ssd130x->width;
+ mode->hsync_start = mode->hsync_end = ssd130x->width;
+ mode->vdisplay = mode->vtotal = ssd130x->height;
+ mode->vsync_start = mode->vsync_end = ssd130x->height;
+ mode->width_mm = 27;
+ mode->height_mm = 27;
+
+ max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
+ max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
+
+ drm->mode_config.min_width = mode->hdisplay;
+ drm->mode_config.max_width = max_width;
+ drm->mode_config.min_height = mode->vdisplay;
+ drm->mode_config.max_height = max_height;
+ drm->mode_config.preferred_depth = 32;
+ drm->mode_config.funcs = &ssd130x_mode_config_funcs;
+
+ ret = drm_connector_init(drm, &ssd130x->connector, &ssd130x_connector_funcs,
+ DRM_MODE_CONNECTOR_Unknown);
+ if (ret) {
+ dev_err(dev, "DRM connector init failed: %d\n", ret);
+ return ret;
+ }
+
+ drm_connector_helper_add(&ssd130x->connector, &ssd130x_connector_helper_funcs);
+
+ ret = drm_simple_display_pipe_init(drm, &ssd130x->pipe, &ssd130x_pipe_funcs,
+ ssd130x_formats, ARRAY_SIZE(ssd130x_formats),
+ NULL, &ssd130x->connector);
+ if (ret) {
+ dev_err(dev, "DRM simple display pipeline init failed: %d\n", ret);
+ return ret;
+ }
+
+ drm_plane_enable_fb_damage_clips(&ssd130x->pipe.plane);
+
+ drm_mode_config_reset(drm);
+
+ return 0;
+}
+
+static int ssd130x_get_resources(struct ssd130x_device *ssd130x)
+{
+ struct device *dev = ssd130x->dev;
+
+ ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(ssd130x->reset))
+ return dev_err_probe(dev, PTR_ERR(ssd130x->reset),
+ "Failed to get reset gpio\n");
+
+ ssd130x->vcc_reg = devm_regulator_get(dev, "vcc");
+ if (IS_ERR(ssd130x->vcc_reg))
+ return dev_err_probe(dev, PTR_ERR(ssd130x->vcc_reg),
+ "Failed to get VCC regulator\n");
+
+ return 0;
+}
+
+struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap)
+{
+ struct ssd130x_device *ssd130x;
+ struct backlight_device *bl;
+ struct drm_device *drm;
+ int ret;
+
+ ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver,
+ struct ssd130x_device, drm);
+ if (IS_ERR(ssd130x)) {
+ dev_err_probe(dev, PTR_ERR(ssd130x),
+ "Failed to allocate DRM device\n");
+ return ssd130x;
+ }
+
+ drm = &ssd130x->drm;
+
+ ssd130x->dev = dev;
+ ssd130x->regmap = regmap;
+ ssd130x->device_info = device_get_match_data(dev);
+
+ ssd130x_parse_properties(ssd130x);
+
+ ret = ssd130x_get_resources(ssd130x);
+ if (ret)
+ return ERR_PTR(ret);
+
+ bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
+ &ssd130xfb_bl_ops, NULL);
+ if (IS_ERR(bl))
+ return ERR_PTR(dev_err_probe(dev, PTR_ERR(bl),
+ "Unable to register backlight device\n"));
+
+ bl->props.brightness = ssd130x->contrast;
+ bl->props.max_brightness = MAX_CONTRAST;
+ ssd130x->bl_dev = bl;
+
+ ret = ssd130x_init_modeset(ssd130x);
+ if (ret)
+ return ERR_PTR(ret);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret)
+ return ERR_PTR(dev_err_probe(dev, ret, "DRM device register failed\n"));
+
+ drm_fbdev_generic_setup(drm, 0);
+
+ return ssd130x;
+}
+EXPORT_SYMBOL_GPL(ssd130x_probe);
+
+int ssd130x_remove(struct ssd130x_device *ssd130x)
+{
+ drm_dev_unplug(&ssd130x->drm);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ssd130x_remove);
+
+void ssd130x_shutdown(struct ssd130x_device *ssd130x)
+{
+ drm_atomic_helper_shutdown(&ssd130x->drm);
+}
+EXPORT_SYMBOL_GPL(ssd130x_shutdown);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/solomon/ssd130x.h b/drivers/gpu/drm/solomon/ssd130x.h
new file mode 100644
index 000000000000..cd21cdccb566
--- /dev/null
+++ b/drivers/gpu/drm/solomon/ssd130x.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Header file for:
+ * DRM driver for Solomon SSD130x OLED displays
+ *
+ * Copyright 2022 Red Hat Inc.
+ * Author: Javier Martinez Canillas <javierm@redhat.com>
+ *
+ * Based on drivers/video/fbdev/ssd1307fb.c
+ * Copyright 2012 Free Electrons
+ */
+
+#ifndef __SSD1307X_H__
+#define __SSD1307X_H__
+
+#include <drm/drm_drv.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#include <linux/regmap.h>
+
+struct ssd130x_deviceinfo {
+ u32 default_vcomh;
+ u32 default_dclk_div;
+ u32 default_dclk_frq;
+ int need_pwm;
+ int need_chargepump;
+};
+
+struct ssd130x_device {
+ struct drm_device drm;
+ struct device *dev;
+ struct drm_simple_display_pipe pipe;
+ struct drm_display_mode mode;
+ struct drm_connector connector;
+ struct i2c_client *client;
+
+ struct regmap *regmap;
+
+ const struct ssd130x_deviceinfo *device_info;
+
+ unsigned area_color_enable : 1;
+ unsigned com_invdir : 1;
+ unsigned com_lrremap : 1;
+ unsigned com_seq : 1;
+ unsigned lookup_table_set : 1;
+ unsigned low_power : 1;
+ unsigned seg_remap : 1;
+ u32 com_offset;
+ u32 contrast;
+ u32 dclk_div;
+ u32 dclk_frq;
+ u32 height;
+ u8 lookup_table[4];
+ u32 page_offset;
+ u32 col_offset;
+ u32 prechargep1;
+ u32 prechargep2;
+
+ struct backlight_device *bl_dev;
+ struct pwm_device *pwm;
+ struct gpio_desc *reset;
+ struct regulator *vcc_reg;
+ u32 vcomh;
+ u32 width;
+ /* Cached address ranges */
+ u8 col_start;
+ u8 col_end;
+ u8 page_start;
+ u8 page_end;
+};
+
+struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap);
+int ssd130x_remove(struct ssd130x_device *ssd130x);
+void ssd130x_shutdown(struct ssd130x_device *ssd130x);
+
+#endif /* __SSD1307X_H__ */
--
2.34.1