From 9c5de2c1754c2bb3c69c4d7bf0d0edc0a61d8232 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 2 Jun 2014 15:38:05 +0200 Subject: [PATCH] spi: rspi: Remove unused 16-bit DMA support The 16-bit DMA support doesn't fit well within the SPI core DMA framework, as it needs to manage its own double-sized temporary buffers, for handling the interleaved data. Remove it, as there is no in-tree board code that sets rspi_plat_data.dma_width_16bit. Signed-off-by: Geert Uytterhoeven Signed-off-by: Mark Brown --- drivers/spi/spi-rspi.c | 84 +++------------------------------------- include/linux/spi/rspi.h | 2 - 2 files changed, 6 insertions(+), 80 deletions(-) diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c index 57beda20959..3bd06fd9af4 100644 --- a/drivers/spi/spi-rspi.c +++ b/drivers/spi/spi-rspi.c @@ -201,7 +201,6 @@ struct rspi_data { struct dma_chan *chan_tx; struct dma_chan *chan_rx; - unsigned dma_width_16bit:1; unsigned dma_callbacked:1; unsigned byte_access:1; }; @@ -475,60 +474,17 @@ static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan, dma_unmap_sg(chan->device->dev, sg, 1, dir); } -static void rspi_memory_to_8bit(void *buf, const void *data, unsigned len) -{ - u16 *dst = buf; - const u8 *src = data; - - while (len) { - *dst++ = (u16)(*src++); - len--; - } -} - -static void rspi_memory_from_8bit(void *buf, const void *data, unsigned len) -{ - u8 *dst = buf; - const u16 *src = data; - - while (len) { - *dst++ = (u8)*src++; - len--; - } -} - static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t) { struct scatterlist sg; - const void *buf = NULL; + const void *buf = t->tx_buf; struct dma_async_tx_descriptor *desc; - unsigned int len; + unsigned int len = t->len; int ret = 0; - if (rspi->dma_width_16bit) { - void *tmp; - /* - * If DMAC bus width is 16-bit, the driver allocates a dummy - * buffer. And, the driver converts original data into the - * DMAC data as the following format: - * original data: 1st byte, 2nd byte ... - * DMAC data: 1st byte, dummy, 2nd byte, dummy ... - */ - len = t->len * 2; - tmp = kmalloc(len, GFP_KERNEL); - if (!tmp) - return -ENOMEM; - rspi_memory_to_8bit(tmp, t->tx_buf, t->len); - buf = tmp; - } else { - len = t->len; - buf = t->tx_buf; - } + if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) + return -EFAULT; - if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) { - ret = -EFAULT; - goto end_nomap; - } desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { @@ -563,10 +519,6 @@ static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t) end: rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE); -end_nomap: - if (rspi->dma_width_16bit) - kfree(buf); - return ret; } @@ -603,28 +555,11 @@ static void qspi_receive_init(const struct rspi_data *rspi) static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t) { struct scatterlist sg, sg_dummy; - void *dummy = NULL, *rx_buf = NULL; + void *dummy = NULL, *rx_buf = t->rx_buf; struct dma_async_tx_descriptor *desc, *desc_dummy; - unsigned int len; + unsigned int len = t->len; int ret = 0; - if (rspi->dma_width_16bit) { - /* - * If DMAC bus width is 16-bit, the driver allocates a dummy - * buffer. And, finally the driver converts the DMAC data into - * actual data as the following format: - * DMAC data: 1st byte, dummy, 2nd byte, dummy ... - * actual data: 1st byte, 2nd byte ... - */ - len = t->len * 2; - rx_buf = kmalloc(len, GFP_KERNEL); - if (!rx_buf) - return -ENOMEM; - } else { - len = t->len; - rx_buf = t->rx_buf; - } - /* prepare dummy transfer to generate SPI clocks */ dummy = kzalloc(len, GFP_KERNEL); if (!dummy) { @@ -697,11 +632,6 @@ end: end_dummy_mapped: rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE); end_nomap: - if (rspi->dma_width_16bit) { - if (!ret) - rspi_memory_from_8bit(t->rx_buf, rx_buf, t->len); - kfree(rx_buf); - } kfree(dummy); return ret; @@ -1073,8 +1003,6 @@ static int rspi_request_dma(struct rspi_data *rspi, if (!res || !rspi_pd) return 0; /* The driver assumes no error. */ - rspi->dma_width_16bit = rspi_pd->dma_width_16bit; - /* If the module receives data by DMAC, it also needs TX DMAC */ if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) { dma_cap_zero(mask); diff --git a/include/linux/spi/rspi.h b/include/linux/spi/rspi.h index a25bd6f65e7..e546b2ceb62 100644 --- a/include/linux/spi/rspi.h +++ b/include/linux/spi/rspi.h @@ -25,8 +25,6 @@ struct rspi_plat_data { unsigned int dma_tx_id; unsigned int dma_rx_id; - unsigned dma_width_16bit:1; /* DMAC read/write width = 16-bit */ - u16 num_chipselect; }; -- 2.46.0