From b0daaa5cfaa561477b8d3d10fb0697a2cce0c2ba Mon Sep 17 00:00:00 2001 From: Chen-Yu Tsai Date: Thu, 7 Apr 2022 01:29:55 +0800 Subject: drm/ssd130x: Support page addressing mode On the SINO WEALTH SH1106, which is mostly compatible with the SSD1306, only the basic page addressing mode is supported. This addressing mode is not as easy to use compared to the currently supported horizontal addressing mode, as the page address has to be set prior to writing out each page, and each page must be written out separately as a result. Also, there is no way to force the column address to wrap around early, thus the column address must also be reset for each page to be accurate. Add support for this addressing mode, with a flag to choose it. This flag is designed to be set from the device info data structure, but can be extended to be explicitly forced on through a device tree property if such a need arises. Signed-off-by: Chen-Yu Tsai Acked-by: Javier Martinez Canillas Signed-off-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20220406172956.3953-4-wens@kernel.org --- drivers/gpu/drm/solomon/ssd130x.c | 73 +++++++++++++++++++++++++++++++++++---- drivers/gpu/drm/solomon/ssd130x.h | 2 ++ 2 files changed, 68 insertions(+), 7 deletions(-) (limited to 'drivers/gpu/drm/solomon') diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c index 38b6c2c14f53..a7e784518c69 100644 --- a/drivers/gpu/drm/solomon/ssd130x.c +++ b/drivers/gpu/drm/solomon/ssd130x.c @@ -42,6 +42,8 @@ #define SSD130X_DATA 0x40 #define SSD130X_COMMAND 0x80 +#define SSD130X_PAGE_COL_START_LOW 0x00 +#define SSD130X_PAGE_COL_START_HIGH 0x10 #define SSD130X_SET_ADDRESS_MODE 0x20 #define SSD130X_SET_COL_RANGE 0x21 #define SSD130X_SET_PAGE_RANGE 0x22 @@ -61,6 +63,11 @@ #define SSD130X_SET_COM_PINS_CONFIG 0xda #define SSD130X_SET_VCOMH 0xdb +#define SSD130X_PAGE_COL_START_MASK GENMASK(3, 0) +#define SSD130X_PAGE_COL_START_HIGH_SET(val) FIELD_PREP(SSD130X_PAGE_COL_START_MASK, (val) >> 4) +#define SSD130X_PAGE_COL_START_LOW_SET(val) FIELD_PREP(SSD130X_PAGE_COL_START_MASK, (val)) +#define SSD130X_START_PAGE_ADDRESS_MASK GENMASK(2, 0) +#define SSD130X_START_PAGE_ADDRESS_SET(val) FIELD_PREP(SSD130X_START_PAGE_ADDRESS_MASK, (val)) #define SSD130X_SET_SEG_REMAP_MASK GENMASK(0, 0) #define SSD130X_SET_SEG_REMAP_SET(val) FIELD_PREP(SSD130X_SET_SEG_REMAP_MASK, (val)) #define SSD130X_SET_COM_SCAN_DIR_MASK GENMASK(3, 3) @@ -130,6 +137,7 @@ out_end: return ret; } +/* Set address range for horizontal/vertical addressing modes */ static int ssd130x_set_col_range(struct ssd130x_device *ssd130x, u8 col_start, u8 cols) { @@ -166,6 +174,26 @@ static int ssd130x_set_page_range(struct ssd130x_device *ssd130x, return 0; } +/* Set page and column start address for page addressing mode */ +static int ssd130x_set_page_pos(struct ssd130x_device *ssd130x, + u8 page_start, u8 col_start) +{ + int ret; + u32 page, col_low, col_high; + + page = SSD130X_START_PAGE_ADDRESS | + SSD130X_START_PAGE_ADDRESS_SET(page_start); + col_low = SSD130X_PAGE_COL_START_LOW | + SSD130X_PAGE_COL_START_LOW_SET(col_start); + col_high = SSD130X_PAGE_COL_START_HIGH | + SSD130X_PAGE_COL_START_HIGH_SET(col_start); + ret = ssd130x_write_cmd(ssd130x, 3, page, col_low, col_high); + if (ret < 0) + return ret; + + return 0; +} + static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x) { struct device *dev = ssd130x->dev; @@ -342,6 +370,11 @@ static int ssd130x_init(struct ssd130x_device *ssd130x) } } + /* Switch to page addressing mode */ + if (ssd130x->page_address_mode) + return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE, + SSD130X_SET_ADDRESS_MODE_PAGE); + /* Switch to horizontal addressing mode */ return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE, SSD130X_SET_ADDRESS_MODE_HORIZONTAL); @@ -396,13 +429,16 @@ static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf, * (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; + if (!ssd130x->page_address_mode) { + /* Set address range for horizontal addressing mode */ + 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; + ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset + y / 8, pages); + if (ret < 0) + goto out_free; + } for (i = 0; i < pages; i++) { int m = 8; @@ -421,9 +457,29 @@ static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf, } data_array[array_idx++] = data; } + + /* + * In page addressing mode, the start address needs to be reset, + * and each page then needs to be written out separately. + */ + if (ssd130x->page_address_mode) { + ret = ssd130x_set_page_pos(ssd130x, + ssd130x->page_offset + i, + ssd130x->col_offset + x); + if (ret < 0) + goto out_free; + + ret = ssd130x_write_data(ssd130x, data_array, width); + if (ret < 0) + goto out_free; + + array_idx = 0; + } } - ret = ssd130x_write_data(ssd130x, data_array, width * pages); + /* Write out update in one go if we aren't using page addressing mode */ + if (!ssd130x->page_address_mode) + ret = ssd130x_write_data(ssd130x, data_array, width * pages); out_free: kfree(data_array); @@ -806,6 +862,9 @@ struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap) ssd130x->regmap = regmap; ssd130x->device_info = device_get_match_data(dev); + if (ssd130x->device_info->page_mode_only) + ssd130x->page_address_mode = 1; + ssd130x_parse_properties(ssd130x); ret = ssd130x_get_resources(ssd130x); diff --git a/drivers/gpu/drm/solomon/ssd130x.h b/drivers/gpu/drm/solomon/ssd130x.h index cd21cdccb566..f5b062576fdf 100644 --- a/drivers/gpu/drm/solomon/ssd130x.h +++ b/drivers/gpu/drm/solomon/ssd130x.h @@ -24,6 +24,7 @@ struct ssd130x_deviceinfo { u32 default_dclk_frq; int need_pwm; int need_chargepump; + bool page_mode_only; }; struct ssd130x_device { @@ -38,6 +39,7 @@ struct ssd130x_device { const struct ssd130x_deviceinfo *device_info; + unsigned page_address_mode : 1; unsigned area_color_enable : 1; unsigned com_invdir : 1; unsigned com_lrremap : 1; -- cgit v1.2.3 From 7cee157b4225089cb831f77515f9c4f4f7c24182 Mon Sep 17 00:00:00 2001 From: Chen-Yu Tsai Date: Thu, 7 Apr 2022 01:29:56 +0800 Subject: drm/ssd130x: Add support for SINO WEALTH SH1106 The SINO WEALTH SH1106 is an OLED display driver that is somewhat compatible with the SSD1306. It supports a slightly wider display, at 132 instead of 128 pixels. The basic commands are the same, but the SH1106 doesn't support the horizontal or vertical address modes. Add support for this display driver. The default values for some of the hardware settings are taken from the datasheet. Signed-off-by: Chen-Yu Tsai Acked-by: Javier Martinez Canillas Signed-off-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20220406172956.3953-5-wens@kernel.org --- drivers/gpu/drm/solomon/Kconfig | 9 +++++---- drivers/gpu/drm/solomon/ssd130x-i2c.c | 11 +++++++++++ 2 files changed, 16 insertions(+), 4 deletions(-) (limited to 'drivers/gpu/drm/solomon') diff --git a/drivers/gpu/drm/solomon/Kconfig b/drivers/gpu/drm/solomon/Kconfig index 6230369505c9..8c0a0c788385 100644 --- a/drivers/gpu/drm/solomon/Kconfig +++ b/drivers/gpu/drm/solomon/Kconfig @@ -5,9 +5,9 @@ config DRM_SSD130X 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. + DRM driver for the SSD130x Solomon and SINO WEALTH SH110x 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. @@ -16,6 +16,7 @@ config DRM_SSD130X_I2C depends on DRM_SSD130X && I2C select REGMAP_I2C help - Say Y here if the SSD130x OLED display is connected via I2C bus. + Say Y here if the SSD130x or SH110x OLED display is connected via + I2C bus. If M is selected the module will be called ssd130x-i2c. diff --git a/drivers/gpu/drm/solomon/ssd130x-i2c.c b/drivers/gpu/drm/solomon/ssd130x-i2c.c index 3126aeda4ced..d099b241dd3f 100644 --- a/drivers/gpu/drm/solomon/ssd130x-i2c.c +++ b/drivers/gpu/drm/solomon/ssd130x-i2c.c @@ -53,6 +53,13 @@ static void ssd130x_i2c_shutdown(struct i2c_client *client) ssd130x_shutdown(ssd130x); } +static struct ssd130x_deviceinfo ssd130x_sh1106_deviceinfo = { + .default_vcomh = 0x40, + .default_dclk_div = 1, + .default_dclk_frq = 5, + .page_mode_only = 1, +}; + static struct ssd130x_deviceinfo ssd130x_ssd1305_deviceinfo = { .default_vcomh = 0x34, .default_dclk_div = 1, @@ -80,6 +87,10 @@ static struct ssd130x_deviceinfo ssd130x_ssd1309_deviceinfo = { }; static const struct of_device_id ssd130x_of_match[] = { + { + .compatible = "sinowealth,sh1106-i2c", + .data = &ssd130x_sh1106_deviceinfo, + }, { .compatible = "solomon,ssd1305fb-i2c", .data = &ssd130x_ssd1305_deviceinfo, -- cgit v1.2.3 From fb197474eddc9369492228f1e423f4ccf0f309b4 Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Tue, 19 Apr 2022 23:48:21 +0200 Subject: drm/solomon: Add ssd130x new compatible strings and deprecate old ones. The current compatible strings for SSD130x I2C controllers contain an "fb" and "-i2c" suffixes. These have been deprecated and more correct ones were added, that don't encode a subsystem or bus used to interface the devices. Signed-off-by: Javier Martinez Canillas Acked-by: Mark Brown Reviewed-by: Geert Uytterhoeven Link: https://patchwork.freedesktop.org/patch/msgid/20220419214824.335075-4-javierm@redhat.com --- drivers/gpu/drm/solomon/ssd130x-i2c.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/solomon') diff --git a/drivers/gpu/drm/solomon/ssd130x-i2c.c b/drivers/gpu/drm/solomon/ssd130x-i2c.c index d099b241dd3f..45867ef2bc8b 100644 --- a/drivers/gpu/drm/solomon/ssd130x-i2c.c +++ b/drivers/gpu/drm/solomon/ssd130x-i2c.c @@ -88,9 +88,26 @@ static struct ssd130x_deviceinfo ssd130x_ssd1309_deviceinfo = { static const struct of_device_id ssd130x_of_match[] = { { - .compatible = "sinowealth,sh1106-i2c", + .compatible = "sinowealth,sh1106", .data = &ssd130x_sh1106_deviceinfo, }, + { + .compatible = "solomon,ssd1305", + .data = &ssd130x_ssd1305_deviceinfo, + }, + { + .compatible = "solomon,ssd1306", + .data = &ssd130x_ssd1306_deviceinfo, + }, + { + .compatible = "solomon,ssd1307", + .data = &ssd130x_ssd1307_deviceinfo, + }, + { + .compatible = "solomon,ssd1309", + .data = &ssd130x_ssd1309_deviceinfo, + }, + /* Deprecated but kept for backward compatibility */ { .compatible = "solomon,ssd1305fb-i2c", .data = &ssd130x_ssd1305_deviceinfo, -- cgit v1.2.3 From 4203e88ba80bbcdfaa7689db286d07cf4f2993d0 Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Tue, 19 Apr 2022 23:48:22 +0200 Subject: drm/solomon: Move device info from ssd130x-i2c to the core driver These are declared in the ssd130x-i2c transport driver but the information is not I2C specific, and could be used by other SSD130x transport drivers. Move them to the ssd130x core driver and just set the OF device entries to an ID that could be used to lookup the correct device info from an array. While being there, also move the SSD130X_DATA and SSD130X_COMMAND control bytes. Since even though they are used by the I2C interface, they could also be useful for other transport protocols such as SPI. Suggested-by: Chen-Yu Tsai Signed-off-by: Javier Martinez Canillas Acked-by: Mark Brown Reviewed-by: Geert Uytterhoeven Link: https://patchwork.freedesktop.org/patch/msgid/20220419214824.335075-5-javierm@redhat.com --- drivers/gpu/drm/solomon/ssd130x-i2c.c | 52 +++++++---------------------------- drivers/gpu/drm/solomon/ssd130x.c | 35 +++++++++++++++++++++-- drivers/gpu/drm/solomon/ssd130x.h | 14 ++++++++++ 3 files changed, 56 insertions(+), 45 deletions(-) (limited to 'drivers/gpu/drm/solomon') diff --git a/drivers/gpu/drm/solomon/ssd130x-i2c.c b/drivers/gpu/drm/solomon/ssd130x-i2c.c index 45867ef2bc8b..d6835ec71c39 100644 --- a/drivers/gpu/drm/solomon/ssd130x-i2c.c +++ b/drivers/gpu/drm/solomon/ssd130x-i2c.c @@ -53,76 +53,43 @@ static void ssd130x_i2c_shutdown(struct i2c_client *client) ssd130x_shutdown(ssd130x); } -static struct ssd130x_deviceinfo ssd130x_sh1106_deviceinfo = { - .default_vcomh = 0x40, - .default_dclk_div = 1, - .default_dclk_frq = 5, - .page_mode_only = 1, -}; - -static struct ssd130x_deviceinfo ssd130x_ssd1305_deviceinfo = { - .default_vcomh = 0x34, - .default_dclk_div = 1, - .default_dclk_frq = 7, -}; - -static struct ssd130x_deviceinfo ssd130x_ssd1306_deviceinfo = { - .default_vcomh = 0x20, - .default_dclk_div = 1, - .default_dclk_frq = 8, - .need_chargepump = 1, -}; - -static struct ssd130x_deviceinfo ssd130x_ssd1307_deviceinfo = { - .default_vcomh = 0x20, - .default_dclk_div = 2, - .default_dclk_frq = 12, - .need_pwm = 1, -}; - -static struct ssd130x_deviceinfo ssd130x_ssd1309_deviceinfo = { - .default_vcomh = 0x34, - .default_dclk_div = 1, - .default_dclk_frq = 10, -}; - static const struct of_device_id ssd130x_of_match[] = { { .compatible = "sinowealth,sh1106", - .data = &ssd130x_sh1106_deviceinfo, + .data = &ssd130x_variants[SH1106_ID], }, { .compatible = "solomon,ssd1305", - .data = &ssd130x_ssd1305_deviceinfo, + .data = &ssd130x_variants[SSD1305_ID], }, { .compatible = "solomon,ssd1306", - .data = &ssd130x_ssd1306_deviceinfo, + .data = &ssd130x_variants[SSD1306_ID], }, { .compatible = "solomon,ssd1307", - .data = &ssd130x_ssd1307_deviceinfo, + .data = &ssd130x_variants[SSD1307_ID], }, { .compatible = "solomon,ssd1309", - .data = &ssd130x_ssd1309_deviceinfo, + .data = &ssd130x_variants[SSD1309_ID], }, /* Deprecated but kept for backward compatibility */ { .compatible = "solomon,ssd1305fb-i2c", - .data = &ssd130x_ssd1305_deviceinfo, + .data = &ssd130x_variants[SSD1305_ID], }, { .compatible = "solomon,ssd1306fb-i2c", - .data = &ssd130x_ssd1306_deviceinfo, + .data = &ssd130x_variants[SSD1306_ID], }, { .compatible = "solomon,ssd1307fb-i2c", - .data = &ssd130x_ssd1307_deviceinfo, + .data = &ssd130x_variants[SSD1307_ID], }, { .compatible = "solomon,ssd1309fb-i2c", - .data = &ssd130x_ssd1309_deviceinfo, + .data = &ssd130x_variants[SSD1309_ID], }, { /* sentinel */ } }; @@ -142,3 +109,4 @@ module_i2c_driver(ssd130x_i2c_driver); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_AUTHOR("Javier Martinez Canillas "); MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS(DRM_SSD130X); diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c index a7e784518c69..ba2de93d00f0 100644 --- a/drivers/gpu/drm/solomon/ssd130x.c +++ b/drivers/gpu/drm/solomon/ssd130x.c @@ -39,9 +39,6 @@ #define DRIVER_MAJOR 1 #define DRIVER_MINOR 0 -#define SSD130X_DATA 0x40 -#define SSD130X_COMMAND 0x80 - #define SSD130X_PAGE_COL_START_LOW 0x00 #define SSD130X_PAGE_COL_START_HIGH 0x10 #define SSD130X_SET_ADDRESS_MODE 0x20 @@ -94,6 +91,38 @@ #define MAX_CONTRAST 255 +const struct ssd130x_deviceinfo ssd130x_variants[] = { + [SH1106_ID] = { + .default_vcomh = 0x40, + .default_dclk_div = 1, + .default_dclk_frq = 5, + .page_mode_only = 1, + }, + [SSD1305_ID] = { + .default_vcomh = 0x34, + .default_dclk_div = 1, + .default_dclk_frq = 7, + }, + [SSD1306_ID] = { + .default_vcomh = 0x20, + .default_dclk_div = 1, + .default_dclk_frq = 8, + .need_chargepump = 1, + }, + [SSD1307_ID] = { + .default_vcomh = 0x20, + .default_dclk_div = 2, + .default_dclk_frq = 12, + .need_pwm = 1, + }, + [SSD1309_ID] = { + .default_vcomh = 0x34, + .default_dclk_div = 1, + .default_dclk_frq = 10, + } +}; +EXPORT_SYMBOL_NS_GPL(ssd130x_variants, DRM_SSD130X); + static inline struct ssd130x_device *drm_to_ssd130x(struct drm_device *drm) { return container_of(drm, struct ssd130x_device, drm); diff --git a/drivers/gpu/drm/solomon/ssd130x.h b/drivers/gpu/drm/solomon/ssd130x.h index f5b062576fdf..d14f78c2eb07 100644 --- a/drivers/gpu/drm/solomon/ssd130x.h +++ b/drivers/gpu/drm/solomon/ssd130x.h @@ -18,6 +18,18 @@ #include +#define SSD130X_DATA 0x40 +#define SSD130X_COMMAND 0x80 + +enum ssd130x_variants { + SH1106_ID, + SSD1305_ID, + SSD1306_ID, + SSD1307_ID, + SSD1309_ID, + NR_SSD130X_VARIANTS +}; + struct ssd130x_deviceinfo { u32 default_vcomh; u32 default_dclk_div; @@ -71,6 +83,8 @@ struct ssd130x_device { u8 page_end; }; +extern const struct ssd130x_deviceinfo ssd130x_variants[]; + 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); -- cgit v1.2.3 From 74373977d2ca26e5735377f8874be70bc2f030f5 Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Tue, 19 Apr 2022 23:48:23 +0200 Subject: drm/solomon: Add SSD130x OLED displays SPI support The ssd130x driver only provides the core support for these devices but it does not have any bus transport logic. Add a driver to interface over SPI. There is a difference in the communication protocol when using 4-wire SPI instead of I2C. For the latter, a control byte that contains a D/C# field has to be sent. This field tells the controller whether the data has to be written to the command register or to the graphics display data memory. But for 4-wire SPI that control byte is not used, instead a real D/C# line must be pulled HIGH for commands data and LOW for graphics display data. For this reason the standard SPI regmap can't be used and a custom .write bus handler is needed. Signed-off-by: Javier Martinez Canillas Acked-by: Mark Brown Reviewed-by: Geert Uytterhoeven Link: https://patchwork.freedesktop.org/patch/msgid/20220419214824.335075-6-javierm@redhat.com --- drivers/gpu/drm/solomon/Kconfig | 9 ++ drivers/gpu/drm/solomon/Makefile | 1 + drivers/gpu/drm/solomon/ssd130x-spi.c | 178 ++++++++++++++++++++++++++++++++++ 3 files changed, 188 insertions(+) create mode 100644 drivers/gpu/drm/solomon/ssd130x-spi.c (limited to 'drivers/gpu/drm/solomon') diff --git a/drivers/gpu/drm/solomon/Kconfig b/drivers/gpu/drm/solomon/Kconfig index 8c0a0c788385..e170716d976b 100644 --- a/drivers/gpu/drm/solomon/Kconfig +++ b/drivers/gpu/drm/solomon/Kconfig @@ -20,3 +20,12 @@ config DRM_SSD130X_I2C I2C bus. If M is selected the module will be called ssd130x-i2c. + +config DRM_SSD130X_SPI + tristate "DRM support for Solomon SSD130X OLED displays (SPI bus)" + depends on DRM_SSD130X && SPI + select REGMAP + help + Say Y here if the SSD130x OLED display is connected via SPI bus. + + If M is selected the module will be called ssd130x-spi. diff --git a/drivers/gpu/drm/solomon/Makefile b/drivers/gpu/drm/solomon/Makefile index 4bfc5acb0447..b5fc792257d7 100644 --- a/drivers/gpu/drm/solomon/Makefile +++ b/drivers/gpu/drm/solomon/Makefile @@ -1,2 +1,3 @@ obj-$(CONFIG_DRM_SSD130X) += ssd130x.o obj-$(CONFIG_DRM_SSD130X_I2C) += ssd130x-i2c.o +obj-$(CONFIG_DRM_SSD130X_SPI) += ssd130x-spi.o diff --git a/drivers/gpu/drm/solomon/ssd130x-spi.c b/drivers/gpu/drm/solomon/ssd130x-spi.c new file mode 100644 index 000000000000..43722adab1f8 --- /dev/null +++ b/drivers/gpu/drm/solomon/ssd130x-spi.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * DRM driver for Solomon SSD130X OLED displays (SPI bus) + * + * Copyright 2022 Red Hat Inc. + * Authors: Javier Martinez Canillas + */ +#include +#include + +#include "ssd130x.h" + +#define DRIVER_NAME "ssd130x-spi" +#define DRIVER_DESC "DRM driver for Solomon SSD130X OLED displays (SPI)" + +struct ssd130x_spi_transport { + struct spi_device *spi; + struct gpio_desc *dc; +}; + +static const struct regmap_config ssd130x_spi_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +/* + * The regmap bus .write handler, it is just a wrapper around spi_write() + * but toggling the Data/Command control pin (D/C#). Since for 4-wire SPI + * a D/C# pin is used, in contrast with I2C where a control byte is sent, + * prior to every data byte, that contains a bit with the D/C# value. + * + * These control bytes are considered registers by the ssd130x core driver + * and can be used by the ssd130x SPI driver to determine if the data sent + * is for a command register or for the Graphic Display Data RAM (GDDRAM). + */ +static int ssd130x_spi_write(void *context, const void *data, size_t count) +{ + struct ssd130x_spi_transport *t = context; + struct spi_device *spi = t->spi; + const u8 *reg = data; + + if (*reg == SSD130X_COMMAND) + gpiod_set_value_cansleep(t->dc, 0); + + if (*reg == SSD130X_DATA) + gpiod_set_value_cansleep(t->dc, 1); + + /* Remove control byte since is not used in a 4-wire SPI interface */ + return spi_write(spi, reg + 1, count - 1); +} + +/* The ssd130x driver does not read registers but regmap expects a .read */ +static int ssd130x_spi_read(void *context, const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + return -EOPNOTSUPP; +} + +/* + * A custom bus is needed due the special write that toggles a D/C# pin, + * another option could be to just have a .reg_write() callback but that + * will prevent to do data writes in bulk. + * + * Once the regmap API is extended to support defining a bulk write handler + * in the struct regmap_config, this can be simplified and the bus dropped. + */ +static struct regmap_bus regmap_ssd130x_spi_bus = { + .write = ssd130x_spi_write, + .read = ssd130x_spi_read, +}; + +static int ssd130x_spi_probe(struct spi_device *spi) +{ + struct ssd130x_spi_transport *t; + struct ssd130x_device *ssd130x; + struct regmap *regmap; + struct gpio_desc *dc; + struct device *dev = &spi->dev; + + dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW); + if (IS_ERR(dc)) + return dev_err_probe(dev, PTR_ERR(dc), + "Failed to get dc gpio\n"); + + t = devm_kzalloc(dev, sizeof(*t), GFP_KERNEL); + if (!t) + return dev_err_probe(dev, -ENOMEM, + "Failed to allocate SPI transport data\n"); + + t->spi = spi; + t->dc = dc; + + regmap = devm_regmap_init(dev, ®map_ssd130x_spi_bus, t, + &ssd130x_spi_regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + ssd130x = ssd130x_probe(dev, regmap); + if (IS_ERR(ssd130x)) + return PTR_ERR(ssd130x); + + spi_set_drvdata(spi, ssd130x); + + return 0; +} + +static void ssd130x_spi_remove(struct spi_device *spi) +{ + struct ssd130x_device *ssd130x = spi_get_drvdata(spi); + + ssd130x_remove(ssd130x); +} + +static void ssd130x_spi_shutdown(struct spi_device *spi) +{ + struct ssd130x_device *ssd130x = spi_get_drvdata(spi); + + ssd130x_shutdown(ssd130x); +} + +static const struct of_device_id ssd130x_of_match[] = { + { + .compatible = "sinowealth,sh1106", + .data = &ssd130x_variants[SH1106_ID], + }, + { + .compatible = "solomon,ssd1305", + .data = &ssd130x_variants[SSD1305_ID], + }, + { + .compatible = "solomon,ssd1306", + .data = &ssd130x_variants[SSD1306_ID], + }, + { + .compatible = "solomon,ssd1307", + .data = &ssd130x_variants[SSD1307_ID], + }, + { + .compatible = "solomon,ssd1309", + .data = &ssd130x_variants[SSD1309_ID], + }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, ssd130x_of_match); + +/* + * The SPI core always reports a MODALIAS uevent of the form "spi:", even + * if the device was registered via OF. This means that the module will not be + * auto loaded, unless it contains an alias that matches the MODALIAS reported. + * + * To workaround this issue, add a SPI device ID table. Even when this should + * not be needed for this driver to match the registered SPI devices. + */ +static const struct spi_device_id ssd130x_spi_table[] = { + { "sh1106", SH1106_ID }, + { "ssd1305", SSD1305_ID }, + { "ssd1306", SSD1306_ID }, + { "ssd1307", SSD1307_ID }, + { "ssd1309", SSD1309_ID }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(spi, ssd130x_spi_table); + +static struct spi_driver ssd130x_spi_driver = { + .driver = { + .name = DRIVER_NAME, + .of_match_table = ssd130x_of_match, + }, + .probe = ssd130x_spi_probe, + .remove = ssd130x_spi_remove, + .shutdown = ssd130x_spi_shutdown, +}; +module_spi_driver(ssd130x_spi_driver); + +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_AUTHOR("Javier Martinez Canillas "); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(DRM_SSD130X); -- cgit v1.2.3