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![Artur Rojek](/assets/img/avatar_default.png)
Add a driver to support the SPI controller found in Ingenic SoCs. Co-developed-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Paul Cercueil <paul@crapouillou.net> Signed-off-by: Artur Rojek <contact@artur-rojek.eu> Link: https://lore.kernel.org/r/20210830230139.21476-3-contact@artur-rojek.eu Signed-off-by: Mark Brown <broonie@kernel.org>
482 lines
13 KiB
C
482 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* SPI bus driver for the Ingenic JZ47xx SoCs
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* Copyright (c) 2017-2021 Artur Rojek <contact@artur-rojek.eu>
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* Copyright (c) 2017-2021 Paul Cercueil <paul@crapouillou.net>
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*/
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/dmaengine.h>
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#include <linux/dma-mapping.h>
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#include <linux/iopoll.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/spi/spi.h>
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#define REG_SSIDR 0x0
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#define REG_SSICR0 0x4
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#define REG_SSICR1 0x8
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#define REG_SSISR 0xc
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#define REG_SSIGR 0x18
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#define REG_SSICR0_TENDIAN_LSB BIT(19)
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#define REG_SSICR0_RENDIAN_LSB BIT(17)
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#define REG_SSICR0_SSIE BIT(15)
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#define REG_SSICR0_LOOP BIT(10)
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#define REG_SSICR0_EACLRUN BIT(7)
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#define REG_SSICR0_FSEL BIT(6)
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#define REG_SSICR0_TFLUSH BIT(2)
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#define REG_SSICR0_RFLUSH BIT(1)
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#define REG_SSICR1_FRMHL_MASK (BIT(31) | BIT(30))
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#define REG_SSICR1_FRMHL BIT(30)
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#define REG_SSICR1_LFST BIT(25)
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#define REG_SSICR1_UNFIN BIT(23)
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#define REG_SSICR1_PHA BIT(1)
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#define REG_SSICR1_POL BIT(0)
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#define REG_SSISR_END BIT(7)
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#define REG_SSISR_BUSY BIT(6)
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#define REG_SSISR_TFF BIT(5)
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#define REG_SSISR_RFE BIT(4)
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#define REG_SSISR_RFHF BIT(2)
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#define REG_SSISR_UNDR BIT(1)
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#define REG_SSISR_OVER BIT(0)
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#define SPI_INGENIC_FIFO_SIZE 128u
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struct jz_soc_info {
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u32 bits_per_word_mask;
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struct reg_field flen_field;
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bool has_trendian;
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};
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struct ingenic_spi {
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const struct jz_soc_info *soc_info;
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struct clk *clk;
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struct resource *mem_res;
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struct regmap *map;
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struct regmap_field *flen_field;
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};
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static int spi_ingenic_wait(struct ingenic_spi *priv,
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unsigned long mask,
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bool condition)
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{
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unsigned int val;
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return regmap_read_poll_timeout(priv->map, REG_SSISR, val,
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!!(val & mask) == condition,
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100, 10000);
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}
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static void spi_ingenic_set_cs(struct spi_device *spi, bool disable)
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{
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struct ingenic_spi *priv = spi_controller_get_devdata(spi->controller);
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if (disable) {
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regmap_clear_bits(priv->map, REG_SSICR1, REG_SSICR1_UNFIN);
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regmap_clear_bits(priv->map, REG_SSISR,
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REG_SSISR_UNDR | REG_SSISR_OVER);
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spi_ingenic_wait(priv, REG_SSISR_END, true);
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} else {
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regmap_set_bits(priv->map, REG_SSICR1, REG_SSICR1_UNFIN);
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}
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regmap_set_bits(priv->map, REG_SSICR0,
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REG_SSICR0_RFLUSH | REG_SSICR0_TFLUSH);
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}
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static void spi_ingenic_prepare_transfer(struct ingenic_spi *priv,
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struct spi_device *spi,
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struct spi_transfer *xfer)
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{
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unsigned long clk_hz = clk_get_rate(priv->clk);
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u32 cdiv, speed_hz = xfer->speed_hz ?: spi->max_speed_hz,
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bits_per_word = xfer->bits_per_word ?: spi->bits_per_word;
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cdiv = clk_hz / (speed_hz * 2);
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cdiv = clamp(cdiv, 1u, 0x100u) - 1;
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regmap_write(priv->map, REG_SSIGR, cdiv);
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regmap_field_write(priv->flen_field, bits_per_word - 2);
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}
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static void spi_ingenic_finalize_transfer(void *controller)
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{
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spi_finalize_current_transfer(controller);
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}
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static struct dma_async_tx_descriptor *
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spi_ingenic_prepare_dma(struct spi_controller *ctlr, struct dma_chan *chan,
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struct sg_table *sg, enum dma_transfer_direction dir,
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unsigned int bits)
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{
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struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
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struct dma_slave_config cfg = {
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.direction = dir,
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.src_addr = priv->mem_res->start + REG_SSIDR,
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.dst_addr = priv->mem_res->start + REG_SSIDR,
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};
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struct dma_async_tx_descriptor *desc;
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dma_cookie_t cookie;
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int ret;
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if (bits > 16) {
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cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
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cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
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cfg.src_maxburst = cfg.dst_maxburst = 4;
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} else if (bits > 8) {
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cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
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cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
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cfg.src_maxburst = cfg.dst_maxburst = 2;
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} else {
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cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
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cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
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cfg.src_maxburst = cfg.dst_maxburst = 1;
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}
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ret = dmaengine_slave_config(chan, &cfg);
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if (ret)
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return ERR_PTR(ret);
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desc = dmaengine_prep_slave_sg(chan, sg->sgl, sg->nents, dir,
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DMA_PREP_INTERRUPT);
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if (!desc)
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return ERR_PTR(-ENOMEM);
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if (dir == DMA_DEV_TO_MEM) {
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desc->callback = spi_ingenic_finalize_transfer;
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desc->callback_param = ctlr;
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}
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cookie = dmaengine_submit(desc);
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ret = dma_submit_error(cookie);
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if (ret) {
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dmaengine_desc_free(desc);
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return ERR_PTR(ret);
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}
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return desc;
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}
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static int spi_ingenic_dma_tx(struct spi_controller *ctlr,
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struct spi_transfer *xfer, unsigned int bits)
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{
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struct dma_async_tx_descriptor *rx_desc, *tx_desc;
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rx_desc = spi_ingenic_prepare_dma(ctlr, ctlr->dma_rx,
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&xfer->rx_sg, DMA_DEV_TO_MEM, bits);
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if (IS_ERR(rx_desc))
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return PTR_ERR(rx_desc);
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tx_desc = spi_ingenic_prepare_dma(ctlr, ctlr->dma_tx,
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&xfer->tx_sg, DMA_MEM_TO_DEV, bits);
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if (IS_ERR(tx_desc)) {
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dmaengine_terminate_async(ctlr->dma_rx);
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dmaengine_desc_free(rx_desc);
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return PTR_ERR(tx_desc);
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}
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dma_async_issue_pending(ctlr->dma_rx);
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dma_async_issue_pending(ctlr->dma_tx);
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return 1;
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}
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#define SPI_INGENIC_TX(x) \
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static int spi_ingenic_tx##x(struct ingenic_spi *priv, \
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struct spi_transfer *xfer) \
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{ \
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unsigned int count = xfer->len / (x / 8); \
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unsigned int prefill = min(count, SPI_INGENIC_FIFO_SIZE); \
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const u##x *tx_buf = xfer->tx_buf; \
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u##x *rx_buf = xfer->rx_buf; \
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unsigned int i, val; \
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int err; \
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\
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/* Fill up the TX fifo */ \
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for (i = 0; i < prefill; i++) { \
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val = tx_buf ? tx_buf[i] : 0; \
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\
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regmap_write(priv->map, REG_SSIDR, val); \
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} \
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\
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for (i = 0; i < count; i++) { \
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err = spi_ingenic_wait(priv, REG_SSISR_RFE, false); \
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if (err) \
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return err; \
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\
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regmap_read(priv->map, REG_SSIDR, &val); \
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if (rx_buf) \
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rx_buf[i] = val; \
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\
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if (i < count - prefill) { \
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val = tx_buf ? tx_buf[i + prefill] : 0; \
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\
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regmap_write(priv->map, REG_SSIDR, val); \
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} \
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} \
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\
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return 0; \
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}
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SPI_INGENIC_TX(8)
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SPI_INGENIC_TX(16)
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SPI_INGENIC_TX(32)
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#undef SPI_INGENIC_TX
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static int spi_ingenic_transfer_one(struct spi_controller *ctlr,
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struct spi_device *spi,
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struct spi_transfer *xfer)
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{
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struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
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unsigned int bits = xfer->bits_per_word ?: spi->bits_per_word;
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bool can_dma = ctlr->can_dma && ctlr->can_dma(ctlr, spi, xfer);
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spi_ingenic_prepare_transfer(priv, spi, xfer);
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if (ctlr->cur_msg_mapped && can_dma)
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return spi_ingenic_dma_tx(ctlr, xfer, bits);
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if (bits > 16)
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return spi_ingenic_tx32(priv, xfer);
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if (bits > 8)
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return spi_ingenic_tx16(priv, xfer);
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return spi_ingenic_tx8(priv, xfer);
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}
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static int spi_ingenic_prepare_message(struct spi_controller *ctlr,
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struct spi_message *message)
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{
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struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
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struct spi_device *spi = message->spi;
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unsigned int cs = REG_SSICR1_FRMHL << spi->chip_select;
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unsigned int ssicr0_mask = REG_SSICR0_LOOP | REG_SSICR0_FSEL;
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unsigned int ssicr1_mask = REG_SSICR1_PHA | REG_SSICR1_POL | cs;
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unsigned int ssicr0 = 0, ssicr1 = 0;
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if (priv->soc_info->has_trendian) {
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ssicr0_mask |= REG_SSICR0_RENDIAN_LSB | REG_SSICR0_TENDIAN_LSB;
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if (spi->mode & SPI_LSB_FIRST)
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ssicr0 |= REG_SSICR0_RENDIAN_LSB | REG_SSICR0_TENDIAN_LSB;
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} else {
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ssicr1_mask |= REG_SSICR1_LFST;
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if (spi->mode & SPI_LSB_FIRST)
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ssicr1 |= REG_SSICR1_LFST;
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}
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if (spi->mode & SPI_LOOP)
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ssicr0 |= REG_SSICR0_LOOP;
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if (spi->chip_select)
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ssicr0 |= REG_SSICR0_FSEL;
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if (spi->mode & SPI_CPHA)
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ssicr1 |= REG_SSICR1_PHA;
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if (spi->mode & SPI_CPOL)
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ssicr1 |= REG_SSICR1_POL;
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if (spi->mode & SPI_CS_HIGH)
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ssicr1 |= cs;
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regmap_update_bits(priv->map, REG_SSICR0, ssicr0_mask, ssicr0);
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regmap_update_bits(priv->map, REG_SSICR1, ssicr1_mask, ssicr1);
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return 0;
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}
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static int spi_ingenic_prepare_hardware(struct spi_controller *ctlr)
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{
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struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
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int ret;
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ret = clk_prepare_enable(priv->clk);
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if (ret)
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return ret;
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regmap_write(priv->map, REG_SSICR0, REG_SSICR0_EACLRUN);
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regmap_write(priv->map, REG_SSICR1, 0);
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regmap_write(priv->map, REG_SSISR, 0);
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regmap_set_bits(priv->map, REG_SSICR0, REG_SSICR0_SSIE);
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return 0;
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}
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static int spi_ingenic_unprepare_hardware(struct spi_controller *ctlr)
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{
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struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
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regmap_clear_bits(priv->map, REG_SSICR0, REG_SSICR0_SSIE);
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clk_disable_unprepare(priv->clk);
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return 0;
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}
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static bool spi_ingenic_can_dma(struct spi_controller *ctlr,
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struct spi_device *spi,
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struct spi_transfer *xfer)
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{
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struct dma_slave_caps caps;
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int ret;
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ret = dma_get_slave_caps(ctlr->dma_tx, &caps);
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if (ret) {
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dev_err(&spi->dev, "Unable to get slave caps: %d\n", ret);
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return false;
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}
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return !caps.max_sg_burst ||
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xfer->len <= caps.max_sg_burst * SPI_INGENIC_FIFO_SIZE;
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}
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static int spi_ingenic_request_dma(struct spi_controller *ctlr,
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struct device *dev)
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{
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ctlr->dma_tx = dma_request_slave_channel(dev, "tx");
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if (!ctlr->dma_tx)
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return -ENODEV;
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ctlr->dma_rx = dma_request_slave_channel(dev, "rx");
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if (!ctlr->dma_rx)
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return -ENODEV;
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ctlr->can_dma = spi_ingenic_can_dma;
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return 0;
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}
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static void spi_ingenic_release_dma(void *data)
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{
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struct spi_controller *ctlr = data;
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if (ctlr->dma_tx)
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dma_release_channel(ctlr->dma_tx);
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if (ctlr->dma_rx)
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dma_release_channel(ctlr->dma_rx);
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}
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static const struct regmap_config spi_ingenic_regmap_config = {
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.reg_bits = 32,
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.val_bits = 32,
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.reg_stride = 4,
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.max_register = REG_SSIGR,
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};
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static int spi_ingenic_probe(struct platform_device *pdev)
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{
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const struct jz_soc_info *pdata;
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struct device *dev = &pdev->dev;
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struct spi_controller *ctlr;
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struct ingenic_spi *priv;
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void __iomem *base;
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int ret;
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pdata = of_device_get_match_data(dev);
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if (!pdata) {
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dev_err(dev, "Missing platform data.\n");
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return -EINVAL;
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}
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ctlr = devm_spi_alloc_master(dev, sizeof(*priv));
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if (!ctlr) {
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dev_err(dev, "Unable to allocate SPI controller.\n");
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return -ENOMEM;
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}
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priv = spi_controller_get_devdata(ctlr);
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priv->soc_info = pdata;
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priv->clk = devm_clk_get(dev, NULL);
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if (IS_ERR(priv->clk)) {
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return dev_err_probe(dev, PTR_ERR(priv->clk),
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"Unable to get clock.\n");
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}
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base = devm_platform_get_and_ioremap_resource(pdev, 0, &priv->mem_res);
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if (IS_ERR(base))
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return PTR_ERR(base);
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priv->map = devm_regmap_init_mmio(dev, base, &spi_ingenic_regmap_config);
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if (IS_ERR(priv->map))
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return PTR_ERR(priv->map);
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priv->flen_field = devm_regmap_field_alloc(dev, priv->map,
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pdata->flen_field);
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if (IS_ERR(priv->flen_field))
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return PTR_ERR(priv->flen_field);
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platform_set_drvdata(pdev, ctlr);
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ctlr->prepare_transfer_hardware = spi_ingenic_prepare_hardware;
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ctlr->unprepare_transfer_hardware = spi_ingenic_unprepare_hardware;
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ctlr->prepare_message = spi_ingenic_prepare_message;
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ctlr->set_cs = spi_ingenic_set_cs;
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ctlr->transfer_one = spi_ingenic_transfer_one;
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ctlr->mode_bits = SPI_MODE_3 | SPI_LSB_FIRST | SPI_LOOP | SPI_CS_HIGH;
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ctlr->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;
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ctlr->max_dma_len = SPI_INGENIC_FIFO_SIZE;
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ctlr->bits_per_word_mask = pdata->bits_per_word_mask;
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ctlr->min_speed_hz = 7200;
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ctlr->max_speed_hz = 54000000;
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ctlr->num_chipselect = 2;
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ctlr->dev.of_node = pdev->dev.of_node;
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if (spi_ingenic_request_dma(ctlr, dev))
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dev_warn(dev, "DMA not available.\n");
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ret = devm_add_action_or_reset(dev, spi_ingenic_release_dma, ctlr);
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if (ret) {
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dev_err(dev, "Unable to add action.\n");
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return ret;
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}
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ret = devm_spi_register_controller(dev, ctlr);
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if (ret)
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dev_err(dev, "Unable to register SPI controller.\n");
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return ret;
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}
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static const struct jz_soc_info jz4750_soc_info = {
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.bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 17),
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.flen_field = REG_FIELD(REG_SSICR1, 4, 7),
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.has_trendian = false,
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};
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static const struct jz_soc_info jz4780_soc_info = {
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.bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 32),
|
|
.flen_field = REG_FIELD(REG_SSICR1, 3, 7),
|
|
.has_trendian = true,
|
|
};
|
|
|
|
static const struct of_device_id spi_ingenic_of_match[] = {
|
|
{ .compatible = "ingenic,jz4750-spi", .data = &jz4750_soc_info },
|
|
{ .compatible = "ingenic,jz4780-spi", .data = &jz4780_soc_info },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, spi_ingenic_of_match);
|
|
|
|
static struct platform_driver spi_ingenic_driver = {
|
|
.driver = {
|
|
.name = "spi-ingenic",
|
|
.of_match_table = spi_ingenic_of_match,
|
|
},
|
|
.probe = spi_ingenic_probe,
|
|
};
|
|
|
|
module_platform_driver(spi_ingenic_driver);
|
|
MODULE_DESCRIPTION("SPI bus driver for the Ingenic JZ47xx SoCs");
|
|
MODULE_AUTHOR("Artur Rojek <contact@artur-rojek.eu>");
|
|
MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
|
|
MODULE_LICENSE("GPL");
|