diff options
Diffstat (limited to 'drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c')
| -rw-r--r-- | drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 207 |
1 files changed, 0 insertions, 207 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 dfeafac4c656..000000000000 --- a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c +++ /dev/null @@ -1,207 +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> - -static unsigned int spi_max; -module_param(spi_max, uint, 0400); -MODULE_PARM_DESC(spi_max, "Set a lower SPI max transfer size"); - -#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; - int i = 0; - - list_for_each_entry(tmp, &m->transfers, 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 */ - -MODULE_LICENSE("GPL"); |