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| author | Noralf Trønnes <noralf@tronnes.org> | 2019-07-19 17:59:12 +0200 |
|---|---|---|
| committer | Noralf Trønnes <noralf@tronnes.org> | 2019-07-23 15:47:33 +0200 |
| commit | d23d4d4dac0119c7bfba63342a86a68b38c01779 (patch) | |
| tree | 1478832fab43424a1759f4528d384baaa35a4956 /drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | |
| parent | 083a6c23b9ecf478265bb27ccacb8d587732058e (diff) | |
| download | lwn-d23d4d4dac0119c7bfba63342a86a68b38c01779.tar.gz lwn-d23d4d4dac0119c7bfba63342a86a68b38c01779.zip | |
drm/tinydrm: Move tinydrm_spi_transfer()
This is only used by mipi-dbi drivers so move it there.
The reason this isn't moved to the SPI subsystem is that it will in a
later patch pass a dummy rx buffer for SPI controllers that need this.
Low memory boards (64MB) can run into a problem allocating such a "large"
contiguous buffer on every transfer after a long up time.
This leaves a very specific use case, so we'll keep the function here.
mipi-dbi will first go through a refactoring though, before this will
be done.
Remove SPI todo entry now that we're done with the tinydrm.ko SPI code.
v2: Drop moving the mipi_dbi_spi_init() declaration (Sam)
Cc: David Lechner <david@lechnology.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: : David Lechner <david@lechnology.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190719155916.62465-8-noralf@tronnes.org
Diffstat (limited to 'drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c')
| -rw-r--r-- | drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 70 |
1 files changed, 0 insertions, 70 deletions
diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c deleted file mode 100644 index d95eb50fa9d4..000000000000 --- a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c +++ /dev/null @@ -1,70 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (C) 2016 Noralf Trønnes - */ - -#include <linux/backlight.h> -#include <linux/dma-buf.h> -#include <linux/module.h> -#include <linux/pm.h> -#include <linux/spi/spi.h> -#include <linux/swab.h> - -#include <drm/drm_device.h> -#include <drm/drm_drv.h> -#include <drm/drm_fourcc.h> -#include <drm/drm_framebuffer.h> -#include <drm/drm_print.h> -#include <drm/drm_rect.h> -#include <drm/tinydrm/tinydrm-helpers.h> - -#if IS_ENABLED(CONFIG_SPI) - -/** - * tinydrm_spi_transfer - SPI transfer helper - * @spi: SPI device - * @speed_hz: Override speed (optional) - * @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 controller driver can handle. - * - * Returns: - * Zero on success, negative error code on failure. - */ -int tinydrm_spi_transfer(struct spi_device *spi, u32 speed_hz, - u8 bpw, const void *buf, size_t len) -{ - size_t max_chunk = spi_max_transfer_size(spi); - struct spi_transfer tr = { - .bits_per_word = bpw, - .speed_hz = speed_hz, - }; - struct spi_message m; - size_t chunk; - int ret; - - spi_message_init_with_transfers(&m, &tr, 1); - - while (len) { - chunk = min(len, max_chunk); - - tr.tx_buf = buf; - tr.len = chunk; - buf += chunk; - len -= chunk; - - ret = spi_sync(spi, &m); - if (ret) - return ret; - } - - return 0; -} -EXPORT_SYMBOL(tinydrm_spi_transfer); - -#endif /* CONFIG_SPI */ - -MODULE_LICENSE("GPL"); |