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