diff options
author | Noralf Trønnes <noralf@tronnes.org> | 2017-01-22 02:30:47 +0300 |
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committer | Noralf Trønnes <noralf@tronnes.org> | 2017-02-18 20:04:59 +0300 |
commit | 02dd95fe316936269a52d6ccb971bb956412b40a (patch) | |
tree | b1bda715ac353c43a6b1309c15b0283f379419a4 /drivers/gpu/drm/tinydrm/mipi-dbi.c | |
parent | 9f69eb5c36a644571cca6b2f8dc5f6a7cba04a8b (diff) | |
download | linux-02dd95fe316936269a52d6ccb971bb956412b40a.tar.xz |
drm/tinydrm: Add MIPI DBI support
Add support for MIPI DBI compatible controllers.
Interface type C option 1 and 3 are supported (SPI).
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/gpu/drm/tinydrm/mipi-dbi.c')
-rw-r--r-- | drivers/gpu/drm/tinydrm/mipi-dbi.c | 1005 |
1 files changed, 1005 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c b/drivers/gpu/drm/tinydrm/mipi-dbi.c new file mode 100644 index 000000000000..07d49ba78d8e --- /dev/null +++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c @@ -0,0 +1,1005 @@ +/* + * MIPI Display Bus Interface (DBI) LCD controller support + * + * Copyright 2016 Noralf Trønnes + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <drm/tinydrm/mipi-dbi.h> +#include <drm/tinydrm/tinydrm-helpers.h> +#include <linux/debugfs.h> +#include <linux/dma-buf.h> +#include <linux/gpio/consumer.h> +#include <linux/module.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h> +#include <video/mipi_display.h> + +#define MIPI_DBI_MAX_SPI_READ_SPEED 2000000 /* 2MHz */ + +#define DCS_POWER_MODE_DISPLAY BIT(2) +#define DCS_POWER_MODE_DISPLAY_NORMAL_MODE BIT(3) +#define DCS_POWER_MODE_SLEEP_MODE BIT(4) +#define DCS_POWER_MODE_PARTIAL_MODE BIT(5) +#define DCS_POWER_MODE_IDLE_MODE BIT(6) +#define DCS_POWER_MODE_RESERVED_MASK (BIT(0) | BIT(1) | BIT(7)) + +/** + * DOC: overview + * + * This library provides helpers for MIPI Display Bus Interface (DBI) + * compatible display controllers. + * + * Many controllers for tiny lcd displays are MIPI compliant and can use this + * library. If a controller uses registers 0x2A and 0x2B to set the area to + * update and uses register 0x2C to write to frame memory, it is most likely + * MIPI compliant. + * + * Only MIPI Type 1 displays are supported since a full frame memory is needed. + * + * There are 3 MIPI DBI implementation types: + * + * A. Motorola 6800 type parallel bus + * + * B. Intel 8080 type parallel bus + * + * C. SPI type with 3 options: + * + * 1. 9-bit with the Data/Command signal as the ninth bit + * 2. Same as above except it's sent as 16 bits + * 3. 8-bit with the Data/Command signal as a separate D/CX pin + * + * Currently mipi_dbi only supports Type C options 1 and 3 with + * mipi_dbi_spi_init(). + */ + +#define MIPI_DBI_DEBUG_COMMAND(cmd, data, len) \ +({ \ + if (!len) \ + DRM_DEBUG_DRIVER("cmd=%02x\n", cmd); \ + else if (len <= 32) \ + DRM_DEBUG_DRIVER("cmd=%02x, par=%*ph\n", cmd, len, data); \ + else \ + DRM_DEBUG_DRIVER("cmd=%02x, len=%zu\n", cmd, len); \ +}) + +static const u8 mipi_dbi_dcs_read_commands[] = { + MIPI_DCS_GET_DISPLAY_ID, + MIPI_DCS_GET_RED_CHANNEL, + MIPI_DCS_GET_GREEN_CHANNEL, + MIPI_DCS_GET_BLUE_CHANNEL, + MIPI_DCS_GET_DISPLAY_STATUS, + MIPI_DCS_GET_POWER_MODE, + MIPI_DCS_GET_ADDRESS_MODE, + MIPI_DCS_GET_PIXEL_FORMAT, + MIPI_DCS_GET_DISPLAY_MODE, + MIPI_DCS_GET_SIGNAL_MODE, + MIPI_DCS_GET_DIAGNOSTIC_RESULT, + MIPI_DCS_READ_MEMORY_START, + MIPI_DCS_READ_MEMORY_CONTINUE, + MIPI_DCS_GET_SCANLINE, + MIPI_DCS_GET_DISPLAY_BRIGHTNESS, + MIPI_DCS_GET_CONTROL_DISPLAY, + MIPI_DCS_GET_POWER_SAVE, + MIPI_DCS_GET_CABC_MIN_BRIGHTNESS, + MIPI_DCS_READ_DDB_START, + MIPI_DCS_READ_DDB_CONTINUE, + 0, /* sentinel */ +}; + +static bool mipi_dbi_command_is_read(struct mipi_dbi *mipi, u8 cmd) +{ + unsigned int i; + + if (!mipi->read_commands) + return false; + + for (i = 0; i < 0xff; i++) { + if (!mipi->read_commands[i]) + return false; + if (cmd == mipi->read_commands[i]) + return true; + } + + return false; +} + +/** + * mipi_dbi_command_read - MIPI DCS read command + * @mipi: MIPI structure + * @cmd: Command + * @val: Value read + * + * Send MIPI DCS read command to the controller. + * + * Returns: + * Zero on success, negative error code on failure. + */ +int mipi_dbi_command_read(struct mipi_dbi *mipi, u8 cmd, u8 *val) +{ + if (!mipi->read_commands) + return -EACCES; + + if (!mipi_dbi_command_is_read(mipi, cmd)) + return -EINVAL; + + return mipi_dbi_command_buf(mipi, cmd, val, 1); +} +EXPORT_SYMBOL(mipi_dbi_command_read); + +/** + * mipi_dbi_command_buf - MIPI DCS command with parameter(s) in an array + * @mipi: MIPI structure + * @cmd: Command + * @data: Parameter buffer + * @len: Buffer length + * + * Returns: + * Zero on success, negative error code on failure. + */ +int mipi_dbi_command_buf(struct mipi_dbi *mipi, u8 cmd, u8 *data, size_t len) +{ + int ret; + + mutex_lock(&mipi->cmdlock); + ret = mipi->command(mipi, cmd, data, len); + mutex_unlock(&mipi->cmdlock); + + return ret; +} +EXPORT_SYMBOL(mipi_dbi_command_buf); + +static int mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb, + struct drm_clip_rect *clip, bool swap) +{ + struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0); + struct dma_buf_attachment *import_attach = cma_obj->base.import_attach; + struct drm_format_name_buf format_name; + void *src = cma_obj->vaddr; + int ret = 0; + + if (import_attach) { + ret = dma_buf_begin_cpu_access(import_attach->dmabuf, + DMA_FROM_DEVICE); + if (ret) + return ret; + } + + switch (fb->format->format) { + case DRM_FORMAT_RGB565: + if (swap) + tinydrm_swab16(dst, src, fb, clip); + else + tinydrm_memcpy(dst, src, fb, clip); + break; + case DRM_FORMAT_XRGB8888: + tinydrm_xrgb8888_to_rgb565(dst, src, fb, clip, swap); + break; + default: + dev_err_once(fb->dev->dev, "Format is not supported: %s\n", + drm_get_format_name(fb->format->format, + &format_name)); + return -EINVAL; + } + + if (import_attach) + ret = dma_buf_end_cpu_access(import_attach->dmabuf, + DMA_FROM_DEVICE); + return ret; +} + +static int mipi_dbi_fb_dirty(struct drm_framebuffer *fb, + struct drm_file *file_priv, + unsigned int flags, unsigned int color, + struct drm_clip_rect *clips, + unsigned int num_clips) +{ + struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0); + struct tinydrm_device *tdev = fb->dev->dev_private; + struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev); + bool swap = mipi->swap_bytes; + struct drm_clip_rect clip; + int ret = 0; + bool full; + void *tr; + + mutex_lock(&tdev->dirty_lock); + + if (!mipi->enabled) + goto out_unlock; + + /* fbdev can flush even when we're not interested */ + if (tdev->pipe.plane.fb != fb) + goto out_unlock; + + full = tinydrm_merge_clips(&clip, clips, num_clips, flags, + fb->width, fb->height); + + DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id, + clip.x1, clip.x2, clip.y1, clip.y2); + + if (!mipi->dc || !full || swap || + fb->format->format == DRM_FORMAT_XRGB8888) { + tr = mipi->tx_buf; + ret = mipi_dbi_buf_copy(mipi->tx_buf, fb, &clip, swap); + if (ret) + goto out_unlock; + } else { + tr = cma_obj->vaddr; + } + + mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS, + (clip.x1 >> 8) & 0xFF, clip.x1 & 0xFF, + (clip.x2 >> 8) & 0xFF, (clip.x2 - 1) & 0xFF); + mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS, + (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF, + (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF); + + ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START, tr, + (clip.x2 - clip.x1) * (clip.y2 - clip.y1) * 2); + +out_unlock: + mutex_unlock(&tdev->dirty_lock); + + if (ret) + dev_err_once(fb->dev->dev, "Failed to update display %d\n", + ret); + + return ret; +} + +static const struct drm_framebuffer_funcs mipi_dbi_fb_funcs = { + .destroy = drm_fb_cma_destroy, + .create_handle = drm_fb_cma_create_handle, + .dirty = mipi_dbi_fb_dirty, +}; + +/** + * mipi_dbi_pipe_enable - MIPI DBI pipe enable helper + * @pipe: Display pipe + * @crtc_state: CRTC state + * + * This function enables backlight. Drivers can use this as their + * &drm_simple_display_pipe_funcs->enable callback. + */ +void mipi_dbi_pipe_enable(struct drm_simple_display_pipe *pipe, + struct drm_crtc_state *crtc_state) +{ + struct tinydrm_device *tdev = pipe_to_tinydrm(pipe); + struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev); + struct drm_framebuffer *fb = pipe->plane.fb; + + DRM_DEBUG_KMS("\n"); + + mipi->enabled = true; + if (fb) + fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0); + + tinydrm_enable_backlight(mipi->backlight); +} +EXPORT_SYMBOL(mipi_dbi_pipe_enable); + +static void mipi_dbi_blank(struct mipi_dbi *mipi) +{ + struct drm_device *drm = mipi->tinydrm.drm; + u16 height = drm->mode_config.min_height; + u16 width = drm->mode_config.min_width; + size_t len = width * height * 2; + + memset(mipi->tx_buf, 0, len); + + mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS, 0, 0, + (width >> 8) & 0xFF, (width - 1) & 0xFF); + mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS, 0, 0, + (height >> 8) & 0xFF, (height - 1) & 0xFF); + mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START, + (u8 *)mipi->tx_buf, len); +} + +/** + * mipi_dbi_pipe_disable - MIPI DBI pipe disable helper + * @pipe: Display pipe + * + * This function disables backlight if present or if not the + * display memory is blanked. Drivers can use this as their + * &drm_simple_display_pipe_funcs->disable callback. + */ +void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe) +{ + struct tinydrm_device *tdev = pipe_to_tinydrm(pipe); + struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev); + + DRM_DEBUG_KMS("\n"); + + mipi->enabled = false; + + if (mipi->backlight) + tinydrm_disable_backlight(mipi->backlight); + else + mipi_dbi_blank(mipi); +} +EXPORT_SYMBOL(mipi_dbi_pipe_disable); + +static const uint32_t mipi_dbi_formats[] = { + DRM_FORMAT_RGB565, + DRM_FORMAT_XRGB8888, +}; + +/** + * mipi_dbi_init - MIPI DBI initialization + * @dev: Parent device + * @mipi: &mipi_dbi structure to initialize + * @pipe_funcs: Display pipe functions + * @driver: DRM driver + * @mode: Display mode + * @rotation: Initial rotation in degrees Counter Clock Wise + * + * This function initializes a &mipi_dbi structure and it's underlying + * @tinydrm_device. It also sets up the display pipeline. + * + * Supported formats: Native RGB565 and emulated XRGB8888. + * + * Objects created by this function will be automatically freed on driver + * detach (devres). + * + * Returns: + * Zero on success, negative error code on failure. + */ +int mipi_dbi_init(struct device *dev, struct mipi_dbi *mipi, + const struct drm_simple_display_pipe_funcs *pipe_funcs, + struct drm_driver *driver, + const struct drm_display_mode *mode, unsigned int rotation) +{ + size_t bufsize = mode->vdisplay * mode->hdisplay * sizeof(u16); + struct tinydrm_device *tdev = &mipi->tinydrm; + int ret; + + if (!mipi->command) + return -EINVAL; + + mutex_init(&mipi->cmdlock); + + mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL); + if (!mipi->tx_buf) + return -ENOMEM; + + ret = devm_tinydrm_init(dev, tdev, &mipi_dbi_fb_funcs, driver); + if (ret) + return ret; + + /* TODO: Maybe add DRM_MODE_CONNECTOR_SPI */ + ret = tinydrm_display_pipe_init(tdev, pipe_funcs, + DRM_MODE_CONNECTOR_VIRTUAL, + mipi_dbi_formats, + ARRAY_SIZE(mipi_dbi_formats), mode, + rotation); + if (ret) + return ret; + + tdev->drm->mode_config.preferred_depth = 16; + mipi->rotation = rotation; + + drm_mode_config_reset(tdev->drm); + + DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n", + tdev->drm->mode_config.preferred_depth, rotation); + + return 0; +} +EXPORT_SYMBOL(mipi_dbi_init); + +/** + * mipi_dbi_hw_reset - Hardware reset of controller + * @mipi: MIPI DBI structure + * + * Reset controller if the &mipi_dbi->reset gpio is set. + */ +void mipi_dbi_hw_reset(struct mipi_dbi *mipi) +{ + if (!mipi->reset) + return; + + gpiod_set_value_cansleep(mipi->reset, 0); + msleep(20); + gpiod_set_value_cansleep(mipi->reset, 1); + msleep(120); +} +EXPORT_SYMBOL(mipi_dbi_hw_reset); + +/** + * mipi_dbi_display_is_on - Check if display is on + * @mipi: MIPI DBI structure + * + * This function checks the Power Mode register (if readable) to see if + * display output is turned on. This can be used to see if the bootloader + * has already turned on the display avoiding flicker when the pipeline is + * enabled. + * + * Returns: + * true if the display can be verified to be on, false otherwise. + */ +bool mipi_dbi_display_is_on(struct mipi_dbi *mipi) +{ + u8 val; + + if (mipi_dbi_command_read(mipi, MIPI_DCS_GET_POWER_MODE, &val)) + return false; + + val &= ~DCS_POWER_MODE_RESERVED_MASK; + + if (val != (DCS_POWER_MODE_DISPLAY | + DCS_POWER_MODE_DISPLAY_NORMAL_MODE | DCS_POWER_MODE_SLEEP_MODE)) + return false; + + DRM_DEBUG_DRIVER("Display is ON\n"); + + return true; +} +EXPORT_SYMBOL(mipi_dbi_display_is_on); + +#if IS_ENABLED(CONFIG_SPI) + +/* + * Many controllers have a max speed of 10MHz, but can be pushed way beyond + * that. Increase reliability by running pixel data at max speed and the rest + * at 10MHz, preventing transfer glitches from messing up the init settings. + */ +static u32 mipi_dbi_spi_cmd_max_speed(struct spi_device *spi, size_t len) +{ + if (len > 64) + return 0; /* use default */ + + return min_t(u32, 10000000, spi->max_speed_hz); +} + +/* + * MIPI DBI Type C Option 1 + * + * If the SPI controller doesn't have 9 bits per word support, + * use blocks of 9 bytes to send 8x 9-bit words using a 8-bit SPI transfer. + * Pad partial blocks with MIPI_DCS_NOP (zero). + * This is how the D/C bit (x) is added: + * x7654321 + * 0x765432 + * 10x76543 + * 210x7654 + * 3210x765 + * 43210x76 + * 543210x7 + * 6543210x + * 76543210 + */ + +static int mipi_dbi_spi1e_transfer(struct mipi_dbi *mipi, int dc, + const void *buf, size_t len, + unsigned int bpw) +{ + bool swap_bytes = (bpw == 16 && tinydrm_machine_little_endian()); + size_t chunk, max_chunk = mipi->tx_buf9_len; + struct spi_device *spi = mipi->spi; + struct spi_transfer tr = { + .tx_buf = mipi->tx_buf9, + .bits_per_word = 8, + }; + struct spi_message m; + const u8 *src = buf; + int i, ret; + u8 *dst; + + if (drm_debug & DRM_UT_DRIVER) + pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n", + __func__, dc, max_chunk); + + tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len); + spi_message_init_with_transfers(&m, &tr, 1); + + if (!dc) { + if (WARN_ON_ONCE(len != 1)) + return -EINVAL; + + /* Command: pad no-op's (zeroes) at beginning of block */ + dst = mipi->tx_buf9; + memset(dst, 0, 9); + dst[8] = *src; + tr.len = 9; + + tinydrm_dbg_spi_message(spi, &m); + + return spi_sync(spi, &m); + } + + /* max with room for adding one bit per byte */ + max_chunk = max_chunk / 9 * 8; + /* but no bigger than len */ + max_chunk = min(max_chunk, len); + /* 8 byte blocks */ + max_chunk = max_t(size_t, 8, max_chunk & ~0x7); + + while (len) { + size_t added = 0; + + chunk = min(len, max_chunk); + len -= chunk; + dst = mipi->tx_buf9; + + if (chunk < 8) { + u8 val, carry = 0; + + /* Data: pad no-op's (zeroes) at end of block */ + memset(dst, 0, 9); + + if (swap_bytes) { + for (i = 1; i < (chunk + 1); i++) { + val = src[1]; + *dst++ = carry | BIT(8 - i) | (val >> i); + carry = val << (8 - i); + i++; + val = src[0]; + *dst++ = carry | BIT(8 - i) | (val >> i); + carry = val << (8 - i); + src += 2; + } + *dst++ = carry; + } else { + for (i = 1; i < (chunk + 1); i++) { + val = *src++; + *dst++ = carry | BIT(8 - i) | (val >> i); + carry = val << (8 - i); + } + *dst++ = carry; + } + + chunk = 8; + added = 1; + } else { + for (i = 0; i < chunk; i += 8) { + if (swap_bytes) { + *dst++ = BIT(7) | (src[1] >> 1); + *dst++ = (src[1] << 7) | BIT(6) | (src[0] >> 2); + *dst++ = (src[0] << 6) | BIT(5) | (src[3] >> 3); + *dst++ = (src[3] << 5) | BIT(4) | (src[2] >> 4); + *dst++ = (src[2] << 4) | BIT(3) | (src[5] >> 5); + *dst++ = (src[5] << 3) | BIT(2) | (src[4] >> 6); + *dst++ = (src[4] << 2) | BIT(1) | (src[7] >> 7); + *dst++ = (src[7] << 1) | BIT(0); + *dst++ = src[6]; + } else { + *dst++ = BIT(7) | (src[0] >> 1); + *dst++ = (src[0] << 7) | BIT(6) | (src[1] >> 2); + *dst++ = (src[1] << 6) | BIT(5) | (src[2] >> 3); + *dst++ = (src[2] << 5) | BIT(4) | (src[3] >> 4); + *dst++ = (src[3] << 4) | BIT(3) | (src[4] >> 5); + *dst++ = (src[4] << 3) | BIT(2) | (src[5] >> 6); + *dst++ = (src[5] << 2) | BIT(1) | (src[6] >> 7); + *dst++ = (src[6] << 1) | BIT(0); + *dst++ = src[7]; + } + + src += 8; + added++; + } + } + + tr.len = chunk + added; + + tinydrm_dbg_spi_message(spi, &m); + ret = spi_sync(spi, &m); + if (ret) + return ret; + }; + + return 0; +} + +static int mipi_dbi_spi1_transfer(struct mipi_dbi *mipi, int dc, + const void *buf, size_t len, + unsigned int bpw) +{ + struct spi_device *spi = mipi->spi; + struct spi_transfer tr = { + .bits_per_word = 9, + }; + const u16 *src16 = buf; + const u8 *src8 = buf; + struct spi_message m; + size_t max_chunk; + u16 *dst16; + int ret; + + if (!tinydrm_spi_bpw_supported(spi, 9)) + return mipi_dbi_spi1e_transfer(mipi, dc, buf, len, bpw); + + tr.speed_hz = mipi_dbi_spi_cmd_max_speed(spi, len); + max_chunk = mipi->tx_buf9_len; + dst16 = mipi->tx_buf9; + + if (drm_debug & DRM_UT_DRIVER) + pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n", + __func__, dc, max_chunk); + + max_chunk = min(max_chunk / 2, len); + + spi_message_init_with_transfers(&m, &tr, 1); + tr.tx_buf = dst16; + + while (len) { + size_t chunk = min(len, max_chunk); + unsigned int i; + + if (bpw == 16 && tinydrm_machine_little_endian()) { + for (i = 0; i < (chunk * 2); i += 2) { + dst16[i] = *src16 >> 8; + dst16[i + 1] = *src16++ & 0xFF; + if (dc) { + dst16[i] |= 0x0100; + dst16[i + 1] |= 0x0100; + } + } + } else { + for (i = 0; i < chunk; i++) { + dst16[i] = *src8++; + if (dc) + dst16[i] |= 0x0100; + } + } + + tr.len = chunk; + len -= chunk; + + tinydrm_dbg_spi_message(spi, &m); + ret = spi_sync(spi, &m); + if (ret) + return ret; + }; + + return 0; +} + +static int mipi_dbi_typec1_command(struct mipi_dbi *mipi, u8 cmd, + u8 *parameters, size_t num) +{ + unsigned int bpw = (cmd == MIPI_DCS_WRITE_MEMORY_START) ? 16 : 8; + int ret; + + if (mipi_dbi_command_is_read(mipi, cmd)) + return -ENOTSUPP; + + MIPI_DBI_DEBUG_COMMAND(cmd, parameters, num); + + ret = mipi_dbi_spi1_transfer(mipi, 0, &cmd, 1, 8); + if (ret || !num) + return ret; + + return mipi_dbi_spi1_transfer(mipi, 1, parameters, num, bpw); +} + +/* MIPI DBI Type C Option 3 */ + +static int mipi_dbi_typec3_command_read(struct mipi_dbi *mipi, u8 cmd, + u8 *data, size_t len) +{ + struct spi_device *spi = mipi->spi; + u32 speed_hz = min_t(u32, MIPI_DBI_MAX_SPI_READ_SPEED, + spi->max_speed_hz / 2); + struct spi_transfer tr[2] = { + { + .speed_hz = speed_hz, + .tx_buf = &cmd, + .len = 1, + }, { + .speed_hz = speed_hz, + .len = len, + }, + }; + struct spi_message m; + u8 *buf; + int ret; + + if (!len) + return -EINVAL; + + /* + * Support non-standard 24-bit and 32-bit Nokia read commands which + * start with a dummy clock, so we need to read an extra byte. + */ + if (cmd == MIPI_DCS_GET_DISPLAY_ID || + cmd == MIPI_DCS_GET_DISPLAY_STATUS) { + if (!(len == 3 || len == 4)) + return -EINVAL; + + tr[1].len = len + 1; + } + + buf = kmalloc(tr[1].len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + tr[1].rx_buf = buf; + gpiod_set_value_cansleep(mipi->dc, 0); + + spi_message_init_with_transfers(&m, tr, ARRAY_SIZE(tr)); + ret = spi_sync(spi, &m); + if (ret) + goto err_free; + + tinydrm_dbg_spi_message(spi, &m); + + if (tr[1].len == len) { + memcpy(data, buf, len); + } else { + unsigned int i; + + for (i = 0; i < len; i++) + data[i] = (buf[i] << 1) | !!(buf[i + 1] & BIT(7)); + } + + MIPI_DBI_DEBUG_COMMAND(cmd, data, len); + +err_free: + kfree(buf); + + return ret; +} + +static int mipi_dbi_typec3_command(struct mipi_dbi *mipi, u8 cmd, + u8 *par, size_t num) +{ + struct spi_device *spi = mipi->spi; + unsigned int bpw = 8; + u32 speed_hz; + int ret; + + if (mipi_dbi_command_is_read(mipi, cmd)) + return mipi_dbi_typec3_command_read(mipi, cmd, par, num); + + MIPI_DBI_DEBUG_COMMAND(cmd, par, num); + + gpiod_set_value_cansleep(mipi->dc, 0); + speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1); + ret = tinydrm_spi_transfer(spi, speed_hz, NULL, 8, &cmd, 1); + if (ret || !num) + return ret; + + if (cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes) + bpw = 16; + + gpiod_set_value_cansleep(mipi->dc, 1); + speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num); + + return tinydrm_spi_transfer(spi, speed_hz, NULL, bpw, par, num); +} + +/** + * mipi_dbi_spi_init - Initialize MIPI DBI SPI interfaced controller + * @spi: SPI device + * @dc: D/C gpio (optional) + * @mipi: &mipi_dbi structure to initialize + * @pipe_funcs: Display pipe functions + * @driver: DRM driver + * @mode: Display mode + * @rotation: Initial rotation in degrees Counter Clock Wise + * + * This function sets &mipi_dbi->command, enables &mipi->read_commands for the + * usual read commands and initializes @mipi using mipi_dbi_init(). + * + * If @dc is set, a Type C Option 3 interface is assumed, if not + * Type C Option 1. + * + * If the SPI master driver doesn't support the necessary bits per word, + * the following transformation is used: + * + * - 9-bit: reorder buffer as 9x 8-bit words, padded with no-op command. + * - 16-bit: if big endian send as 8-bit, if little endian swap bytes + * + * Returns: + * Zero on success, negative error code on failure. + */ +int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *mipi, + struct gpio_desc *dc, + const struct drm_simple_display_pipe_funcs *pipe_funcs, + struct drm_driver *driver, + const struct drm_display_mode *mode, + unsigned int rotation) +{ + size_t tx_size = tinydrm_spi_max_transfer_size(spi, 0); + struct device *dev = &spi->dev; + int ret; + + if (tx_size < 16) { + DRM_ERROR("SPI transmit buffer too small: %zu\n", tx_size); + return -EINVAL; + } + + /* + * Even though it's not the SPI device that does DMA (the master does), + * the dma mask is necessary for the dma_alloc_wc() in + * drm_gem_cma_create(). The dma_addr returned will be a physical + * adddress which might be different from the bus address, but this is + * not a problem since the address will not be used. + * The virtual address is used in the transfer and the SPI core + * re-maps it on the SPI master device using the DMA streaming API + * (spi_map_buf()). + */ + if (!dev->coherent_dma_mask) { + ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); + if (ret) { + dev_warn(dev, "Failed to set dma mask %d\n", ret); + return ret; + } + } + + mipi->spi = spi; + mipi->read_commands = mipi_dbi_dcs_read_commands; + + if (dc) { + mipi->command = mipi_dbi_typec3_command; + mipi->dc = dc; + if (tinydrm_machine_little_endian() && + !tinydrm_spi_bpw_supported(spi, 16)) + mipi->swap_bytes = true; + } else { + mipi->command = mipi_dbi_typec1_command; + mipi->tx_buf9_len = tx_size; + mipi->tx_buf9 = devm_kmalloc(dev, tx_size, GFP_KERNEL); + if (!mipi->tx_buf9) + return -ENOMEM; + } + + return mipi_dbi_init(dev, mipi, pipe_funcs, driver, mode, rotation); +} +EXPORT_SYMBOL(mipi_dbi_spi_init); + +#endif /* CONFIG_SPI */ + +#ifdef CONFIG_DEBUG_FS + +static ssize_t mipi_dbi_debugfs_command_write(struct file *file, + const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct mipi_dbi *mipi = m->private; + u8 val, cmd, parameters[64]; + char *buf, *pos, *token; + unsigned int i; + int ret; + + buf = memdup_user_nul(ubuf, count); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + /* strip trailing whitespace */ + for (i = count - 1; i > 0; i--) + if (isspace(buf[i])) + buf[i] = '\0'; + else + break; + i = 0; + pos = buf; + while (pos) { + token = strsep(&pos, " "); + if (!token) { + ret = -EINVAL; + goto err_free; + } + + ret = kstrtou8(token, 16, &val); + if (ret < 0) + goto err_free; + + if (token == buf) + cmd = val; + else + parameters[i++] = val; + + if (i == 64) { + ret = -E2BIG; + goto err_free; + } + } + + ret = mipi_dbi_command_buf(mipi, cmd, parameters, i); + +err_free: + kfree(buf); + + return ret < 0 ? ret : count; +} + +static int mipi_dbi_debugfs_command_show(struct seq_file *m, void *unused) +{ + struct mipi_dbi *mipi = m->private; + u8 cmd, val[4]; + size_t len, i; + int ret; + + for (cmd = 0; cmd < 255; cmd++) { + if (!mipi_dbi_command_is_read(mipi, cmd)) + continue; + + switch (cmd) { + case MIPI_DCS_READ_MEMORY_START: + case MIPI_DCS_READ_MEMORY_CONTINUE: + len = 2; + break; + case MIPI_DCS_GET_DISPLAY_ID: + len = 3; + break; + case MIPI_DCS_GET_DISPLAY_STATUS: + len = 4; + break; + default: + len = 1; + break; + } + + seq_printf(m, "%02x: ", cmd); + ret = mipi_dbi_command_buf(mipi, cmd, val, len); + if (ret) { + seq_puts(m, "XX\n"); + continue; + } + + for (i = 0; i < len; i++) + seq_printf(m, "%02x", val[i]); + seq_puts(m, "\n"); + } + + return 0; +} + +static int mipi_dbi_debugfs_command_open(struct inode *inode, + struct file *file) +{ + return single_open(file, mipi_dbi_debugfs_command_show, + inode->i_private); +} + +static const struct file_operations mipi_dbi_debugfs_command_fops = { + .owner = THIS_MODULE, + .open = mipi_dbi_debugfs_command_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = mipi_dbi_debugfs_command_write, +}; + +static const struct drm_info_list mipi_dbi_debugfs_list[] = { + { "fb", drm_fb_cma_debugfs_show, 0 }, +}; + +/** + * mipi_dbi_debugfs_init - Create debugfs entries + * @minor: DRM minor + * + * This function creates a 'command' debugfs file for sending commands to the + * controller or getting the read command values. + * Drivers can use this as their &drm_driver->debugfs_init callback. + * + * Returns: + * Zero on success, negative error code on failure. + */ +int mipi_dbi_debugfs_init(struct drm_minor *minor) +{ + struct tinydrm_device *tdev = minor->dev->dev_private; + struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev); + umode_t mode = S_IFREG | S_IWUSR; + + if (mipi->read_commands) + mode |= S_IRUGO; + debugfs_create_file("command", mode, minor->debugfs_root, mipi, + &mipi_dbi_debugfs_command_fops); + + return drm_debugfs_create_files(mipi_dbi_debugfs_list, + ARRAY_SIZE(mipi_dbi_debugfs_list), + minor->debugfs_root, minor); +} +EXPORT_SYMBOL(mipi_dbi_debugfs_init); + +#endif + +MODULE_LICENSE("GPL"); |