diff options
Diffstat (limited to 'drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c')
| -rw-r--r-- | drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 460 |
1 files changed, 460 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c new file mode 100644 index 000000000000..3ccda6c1e159 --- /dev/null +++ b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c @@ -0,0 +1,460 @@ +/* + * Copyright (C) 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/tinydrm.h> +#include <drm/tinydrm/tinydrm-helpers.h> +#include <linux/backlight.h> +#include <linux/pm.h> +#include <linux/spi/spi.h> +#include <linux/swab.h> + +static unsigned int spi_max; +module_param(spi_max, uint, 0400); +MODULE_PARM_DESC(spi_max, "Set a lower SPI max transfer size"); + +/** + * tinydrm_merge_clips - Merge clip rectangles + * @dst: Destination clip rectangle + * @src: Source clip rectangle(s) + * @num_clips: Number of @src clip rectangles + * @flags: Dirty fb ioctl flags + * @max_width: Maximum width of @dst + * @max_height: Maximum height of @dst + * + * This function merges @src clip rectangle(s) into @dst. If @src is NULL, + * @max_width and @min_width is used to set a full @dst clip rectangle. + * + * Returns: + * true if it's a full clip, false otherwise + */ +bool tinydrm_merge_clips(struct drm_clip_rect *dst, + struct drm_clip_rect *src, unsigned int num_clips, + unsigned int flags, u32 max_width, u32 max_height) +{ + unsigned int i; + + if (!src || !num_clips) { + dst->x1 = 0; + dst->x2 = max_width; + dst->y1 = 0; + dst->y2 = max_height; + return true; + } + + dst->x1 = ~0; + dst->y1 = ~0; + dst->x2 = 0; + dst->y2 = 0; + + for (i = 0; i < num_clips; i++) { + if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY) + i++; + dst->x1 = min(dst->x1, src[i].x1); + dst->x2 = max(dst->x2, src[i].x2); + dst->y1 = min(dst->y1, src[i].y1); + dst->y2 = max(dst->y2, src[i].y2); + } + + if (dst->x2 > max_width || dst->y2 > max_height || + dst->x1 >= dst->x2 || dst->y1 >= dst->y2) { + DRM_DEBUG_KMS("Illegal clip: x1=%u, x2=%u, y1=%u, y2=%u\n", + dst->x1, dst->x2, dst->y1, dst->y2); + dst->x1 = 0; + dst->y1 = 0; + dst->x2 = max_width; + dst->y2 = max_height; + } + + return (dst->x2 - dst->x1) == max_width && + (dst->y2 - dst->y1) == max_height; +} +EXPORT_SYMBOL(tinydrm_merge_clips); + +/** + * tinydrm_memcpy - Copy clip buffer + * @dst: Destination buffer + * @vaddr: Source buffer + * @fb: DRM framebuffer + * @clip: Clip rectangle area to copy + */ +void tinydrm_memcpy(void *dst, void *vaddr, struct drm_framebuffer *fb, + struct drm_clip_rect *clip) +{ + unsigned int cpp = drm_format_plane_cpp(fb->format->format, 0); + unsigned int pitch = fb->pitches[0]; + void *src = vaddr + (clip->y1 * pitch) + (clip->x1 * cpp); + size_t len = (clip->x2 - clip->x1) * cpp; + unsigned int y; + + for (y = clip->y1; y < clip->y2; y++) { + memcpy(dst, src, len); + src += pitch; + dst += len; + } +} +EXPORT_SYMBOL(tinydrm_memcpy); + +/** + * tinydrm_swab16 - Swap bytes into clip buffer + * @dst: RGB565 destination buffer + * @vaddr: RGB565 source buffer + * @fb: DRM framebuffer + * @clip: Clip rectangle area to copy + */ +void tinydrm_swab16(u16 *dst, void *vaddr, struct drm_framebuffer *fb, + struct drm_clip_rect *clip) +{ + size_t len = (clip->x2 - clip->x1) * sizeof(u16); + unsigned int x, y; + u16 *src, *buf; + + /* + * The cma memory is write-combined so reads are uncached. + * Speed up by fetching one line at a time. + */ + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + return; + + for (y = clip->y1; y < clip->y2; y++) { + src = vaddr + (y * fb->pitches[0]); + src += clip->x1; + memcpy(buf, src, len); + src = buf; + for (x = clip->x1; x < clip->x2; x++) + *dst++ = swab16(*src++); + } + + kfree(buf); +} +EXPORT_SYMBOL(tinydrm_swab16); + +/** + * tinydrm_xrgb8888_to_rgb565 - Convert XRGB8888 to RGB565 clip buffer + * @dst: RGB565 destination buffer + * @vaddr: XRGB8888 source buffer + * @fb: DRM framebuffer + * @clip: Clip rectangle area to copy + * @swap: Swap bytes + * + * Drivers can use this function for RGB565 devices that don't natively + * support XRGB8888. + */ +void tinydrm_xrgb8888_to_rgb565(u16 *dst, void *vaddr, + struct drm_framebuffer *fb, + struct drm_clip_rect *clip, bool swap) +{ + size_t len = (clip->x2 - clip->x1) * sizeof(u32); + unsigned int x, y; + u32 *src, *buf; + u16 val16; + + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + return; + + for (y = clip->y1; y < clip->y2; y++) { + src = vaddr + (y * fb->pitches[0]); + src += clip->x1; + memcpy(buf, src, len); + src = buf; + for (x = clip->x1; x < clip->x2; x++) { + val16 = ((*src & 0x00F80000) >> 8) | + ((*src & 0x0000FC00) >> 5) | + ((*src & 0x000000F8) >> 3); + src++; + if (swap) + *dst++ = swab16(val16); + else + *dst++ = val16; + } + } + + kfree(buf); +} +EXPORT_SYMBOL(tinydrm_xrgb8888_to_rgb565); + +/** + * tinydrm_of_find_backlight - Find backlight device in device-tree + * @dev: Device + * + * This function looks for a DT node pointed to by a property named 'backlight' + * and uses of_find_backlight_by_node() to get the backlight device. + * Additionally if the brightness property is zero, it is set to + * max_brightness. + * + * Returns: + * NULL if there's no backlight property. + * Error pointer -EPROBE_DEFER if the DT node is found, but no backlight device + * is found. + * If the backlight device is found, a pointer to the structure is returned. + */ +struct backlight_device *tinydrm_of_find_backlight(struct device *dev) +{ + struct backlight_device *backlight; + struct device_node *np; + + np = of_parse_phandle(dev->of_node, "backlight", 0); + if (!np) + return NULL; + + backlight = of_find_backlight_by_node(np); + of_node_put(np); + + if (!backlight) + return ERR_PTR(-EPROBE_DEFER); + + if (!backlight->props.brightness) { + backlight->props.brightness = backlight->props.max_brightness; + DRM_DEBUG_KMS("Backlight brightness set to %d\n", + backlight->props.brightness); + } + + return backlight; +} +EXPORT_SYMBOL(tinydrm_of_find_backlight); + +/** + * tinydrm_enable_backlight - Enable backlight helper + * @backlight: Backlight device + * + * Returns: + * Zero on success, negative error code on failure. + */ +int tinydrm_enable_backlight(struct backlight_device *backlight) +{ + unsigned int old_state; + int ret; + + if (!backlight) + return 0; + + old_state = backlight->props.state; + backlight->props.state &= ~BL_CORE_FBBLANK; + DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state, + backlight->props.state); + + ret = backlight_update_status(backlight); + if (ret) + DRM_ERROR("Failed to enable backlight %d\n", ret); + + return ret; +} +EXPORT_SYMBOL(tinydrm_enable_backlight); + +/** + * tinydrm_disable_backlight - Disable backlight helper + * @backlight: Backlight device + * + * Returns: + * Zero on success, negative error code on failure. + */ +int tinydrm_disable_backlight(struct backlight_device *backlight) +{ + unsigned int old_state; + int ret; + + if (!backlight) + return 0; + + old_state = backlight->props.state; + backlight->props.state |= BL_CORE_FBBLANK; + DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state, + backlight->props.state); + ret = backlight_update_status(backlight); + if (ret) + DRM_ERROR("Failed to disable backlight %d\n", ret); + + return ret; +} +EXPORT_SYMBOL(tinydrm_disable_backlight); + +#if IS_ENABLED(CONFIG_SPI) + +/** + * tinydrm_spi_max_transfer_size - Determine max SPI transfer size + * @spi: SPI device + * @max_len: Maximum buffer size needed (optional) + * + * This function returns the maximum size to use for SPI transfers. It checks + * the SPI master, the optional @max_len and the module parameter spi_max and + * returns the smallest. + * + * Returns: + * Maximum size for SPI transfers + */ +size_t tinydrm_spi_max_transfer_size(struct spi_device *spi, size_t max_len) +{ + size_t ret; + + ret = min(spi_max_transfer_size(spi), spi->master->max_dma_len); + if (max_len) + ret = min(ret, max_len); + if (spi_max) + ret = min_t(size_t, ret, spi_max); + ret &= ~0x3; + if (ret < 4) + ret = 4; + + return ret; +} +EXPORT_SYMBOL(tinydrm_spi_max_transfer_size); + +/** + * tinydrm_spi_bpw_supported - Check if bits per word is supported + * @spi: SPI device + * @bpw: Bits per word + * + * This function checks to see if the SPI master driver supports @bpw. + * + * Returns: + * True if @bpw is supported, false otherwise. + */ +bool tinydrm_spi_bpw_supported(struct spi_device *spi, u8 bpw) +{ + u32 bpw_mask = spi->master->bits_per_word_mask; + + if (bpw == 8) + return true; + + if (!bpw_mask) { + dev_warn_once(&spi->dev, + "bits_per_word_mask not set, assume 8-bit only\n"); + return false; + } + + if (bpw_mask & SPI_BPW_MASK(bpw)) + return true; + + return false; +} +EXPORT_SYMBOL(tinydrm_spi_bpw_supported); + +static void +tinydrm_dbg_spi_print(struct spi_device *spi, struct spi_transfer *tr, + const void *buf, int idx, bool tx) +{ + u32 speed_hz = tr->speed_hz ? tr->speed_hz : spi->max_speed_hz; + char linebuf[3 * 32]; + + hex_dump_to_buffer(buf, tr->len, 16, + DIV_ROUND_UP(tr->bits_per_word, 8), + linebuf, sizeof(linebuf), false); + + printk(KERN_DEBUG + " tr(%i): speed=%u%s, bpw=%i, len=%u, %s_buf=[%s%s]\n", idx, + speed_hz > 1000000 ? speed_hz / 1000000 : speed_hz / 1000, + speed_hz > 1000000 ? "MHz" : "kHz", tr->bits_per_word, tr->len, + tx ? "tx" : "rx", linebuf, tr->len > 16 ? " ..." : ""); +} + +/* called through tinydrm_dbg_spi_message() */ +void _tinydrm_dbg_spi_message(struct spi_device *spi, struct spi_message *m) +{ + struct spi_transfer *tmp; + struct list_head *pos; + int i = 0; + + list_for_each(pos, &m->transfers) { + tmp = list_entry(pos, struct spi_transfer, transfer_list); + + if (tmp->tx_buf) + tinydrm_dbg_spi_print(spi, tmp, tmp->tx_buf, i, true); + if (tmp->rx_buf) + tinydrm_dbg_spi_print(spi, tmp, tmp->rx_buf, i, false); + i++; + } +} +EXPORT_SYMBOL(_tinydrm_dbg_spi_message); + +/** + * tinydrm_spi_transfer - SPI transfer helper + * @spi: SPI device + * @speed_hz: Override speed (optional) + * @header: Optional header transfer + * @bpw: Bits per word + * @buf: Buffer to transfer + * @len: Buffer length + * + * This SPI transfer helper breaks up the transfer of @buf into chunks which + * the SPI master driver can handle. If the machine is Little Endian and the + * SPI master driver doesn't support 16 bits per word, it swaps the bytes and + * does a 8-bit transfer. + * If @header is set, it is prepended to each SPI message. + * + * Returns: + * Zero on success, negative error code on failure. + */ +int tinydrm_spi_transfer(struct spi_device *spi, u32 speed_hz, + struct spi_transfer *header, u8 bpw, const void *buf, + size_t len) +{ + struct spi_transfer tr = { + .bits_per_word = bpw, + .speed_hz = speed_hz, + }; + struct spi_message m; + u16 *swap_buf = NULL; + size_t max_chunk; + size_t chunk; + int ret = 0; + + if (WARN_ON_ONCE(bpw != 8 && bpw != 16)) + return -EINVAL; + + max_chunk = tinydrm_spi_max_transfer_size(spi, 0); + + if (drm_debug & DRM_UT_DRIVER) + pr_debug("[drm:%s] bpw=%u, max_chunk=%zu, transfers:\n", + __func__, bpw, max_chunk); + + if (bpw == 16 && !tinydrm_spi_bpw_supported(spi, 16)) { + tr.bits_per_word = 8; + if (tinydrm_machine_little_endian()) { + swap_buf = kmalloc(min(len, max_chunk), GFP_KERNEL); + if (!swap_buf) + return -ENOMEM; + } + } + + spi_message_init(&m); + if (header) + spi_message_add_tail(header, &m); + spi_message_add_tail(&tr, &m); + + while (len) { + chunk = min(len, max_chunk); + + tr.tx_buf = buf; + tr.len = chunk; + + if (swap_buf) { + const u16 *buf16 = buf; + unsigned int i; + + for (i = 0; i < chunk / 2; i++) + swap_buf[i] = swab16(buf16[i]); + + tr.tx_buf = swap_buf; + } + + buf += chunk; + len -= chunk; + + tinydrm_dbg_spi_message(spi, &m); + ret = spi_sync(spi, &m); + if (ret) + return ret; + }; + + return 0; +} +EXPORT_SYMBOL(tinydrm_spi_transfer); + +#endif /* CONFIG_SPI */ |