drm/tinydrm: Add helper functions

Add common functionality needed by many tinydrm drivers.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Noralf Trønnes 2017-01-22 00:19:51 +01:00
parent fa201ac2c6
commit 9f69eb5c36
5 changed files with 572 additions and 1 deletions

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@ -19,3 +19,12 @@ Core functionality
.. kernel-doc:: drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c
:export:
Additional helpers
==================
.. kernel-doc:: include/drm/tinydrm/tinydrm-helpers.h
:internal:
.. kernel-doc:: drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
:export:

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@ -3,6 +3,8 @@ menuconfig DRM_TINYDRM
depends on DRM
select DRM_KMS_HELPER
select DRM_KMS_CMA_HELPER
select BACKLIGHT_LCD_SUPPORT
select BACKLIGHT_CLASS_DEVICE
help
Choose this option if you have a tinydrm supported display.
If M is selected the module will be called tinydrm.

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@ -1,3 +1,3 @@
tinydrm-y := tinydrm-core.o tinydrm-pipe.o
tinydrm-y := tinydrm-core.o tinydrm-pipe.o tinydrm-helpers.o
obj-$(CONFIG_DRM_TINYDRM) += tinydrm.o

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@ -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 */

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@ -0,0 +1,100 @@
/*
* 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.
*/
#ifndef __LINUX_TINYDRM_HELPERS_H
#define __LINUX_TINYDRM_HELPERS_H
struct backlight_device;
struct tinydrm_device;
struct drm_clip_rect;
struct spi_transfer;
struct spi_message;
struct spi_device;
struct device;
/**
* tinydrm_machine_little_endian - Machine is little endian
*
* Returns:
* true if *defined(__LITTLE_ENDIAN)*, false otherwise
*/
static inline bool tinydrm_machine_little_endian(void)
{
#if defined(__LITTLE_ENDIAN)
return true;
#else
return false;
#endif
}
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);
void tinydrm_memcpy(void *dst, void *vaddr, struct drm_framebuffer *fb,
struct drm_clip_rect *clip);
void tinydrm_swab16(u16 *dst, void *vaddr, struct drm_framebuffer *fb,
struct drm_clip_rect *clip);
void tinydrm_xrgb8888_to_rgb565(u16 *dst, void *vaddr,
struct drm_framebuffer *fb,
struct drm_clip_rect *clip, bool swap);
#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
struct backlight_device *tinydrm_of_find_backlight(struct device *dev);
int tinydrm_enable_backlight(struct backlight_device *backlight);
int tinydrm_disable_backlight(struct backlight_device *backlight);
#else
static inline struct backlight_device *
tinydrm_of_find_backlight(struct device *dev)
{
return NULL;
}
static inline int tinydrm_enable_backlight(struct backlight_device *backlight)
{
return 0;
}
static inline int
tinydrm_disable_backlight(struct backlight_device *backlight)
{
return 0;
}
#endif
size_t tinydrm_spi_max_transfer_size(struct spi_device *spi, size_t max_len);
bool tinydrm_spi_bpw_supported(struct spi_device *spi, u8 bpw);
int tinydrm_spi_transfer(struct spi_device *spi, u32 speed_hz,
struct spi_transfer *header, u8 bpw, const void *buf,
size_t len);
void _tinydrm_dbg_spi_message(struct spi_device *spi, struct spi_message *m);
#ifdef DEBUG
/**
* tinydrm_dbg_spi_message - Dump SPI message
* @spi: SPI device
* @m: SPI message
*
* Dumps info about the transfers in a SPI message including buffer content.
* DEBUG has to be defined for this function to be enabled alongside setting
* the DRM_UT_DRIVER bit of &drm_debug.
*/
static inline void tinydrm_dbg_spi_message(struct spi_device *spi,
struct spi_message *m)
{
if (drm_debug & DRM_UT_DRIVER)
_tinydrm_dbg_spi_message(spi, m);
}
#else
static inline void tinydrm_dbg_spi_message(struct spi_device *spi,
struct spi_message *m)
{
}
#endif /* DEBUG */
#endif /* __LINUX_TINYDRM_HELPERS_H */