On Tue, Jan 31, 2017 at 05:03:14PM +0100, Noralf Trønnes wrote:
> Add common functionality needed by many tinydrm drivers.
>
> Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
> Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> ---
> Documentation/gpu/tinydrm.rst | 9 +
> drivers/gpu/drm/tinydrm/core/Makefile | 2 +-
> drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 462 +++++++++++++++++++++++++
> include/drm/tinydrm/tinydrm-helpers.h | 100 ++++++
> 4 files changed, 572 insertions(+), 1 deletion(-)
> create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
> create mode 100644 include/drm/tinydrm/tinydrm-helpers.h
>
> diff --git a/Documentation/gpu/tinydrm.rst b/Documentation/gpu/tinydrm.rst
> index ec4a20d..fb256d2 100644
> --- a/Documentation/gpu/tinydrm.rst
> +++ b/Documentation/gpu/tinydrm.rst
> @@ -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:
> diff --git a/drivers/gpu/drm/tinydrm/core/Makefile b/drivers/gpu/drm/tinydrm/core/Makefile
> index 4f14a0f..fb221e6 100644
> --- a/drivers/gpu/drm/tinydrm/core/Makefile
> +++ b/drivers/gpu/drm/tinydrm/core/Makefile
> @@ -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
> 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 0000000..75e4e54
> --- /dev/null
> +++ b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
> @@ -0,0 +1,462 @@
> +/*
> + * 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);
Should this perhaps be part of drm_rect.c?
> +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
> +/**
> + * 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);
> +#endif
These look like they really should be part of the backlight subsystem. I
don't see anything DRM specific about them. Well, except for the error
messages.
> +#ifdef 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);
Similarly for the above.
Thierry
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