Merge series "Support for Ingenic JZ47xx SPI controller" from Artur Rojek <contact@artur-rojek.eu>:

Hi,

This patchset introduces support for SPI controllers found in the
Ingenic JZ47xx family of SoCs. Of particular note, this allows to
replace GPIO backed SPI on the MIPS Creator CI20 board.

Mark:
Checkpatch generates a `need consistent spacing around '*'` error on
this patchset, however I believe this is a false positive due to it
confusing a pointer with multiplication operator inside a macro.

Rob:
I refrained from adding SPI pin groups into the bindings, as I felt that
would be enforcing a policy (SPI signals can be multiplexed on multiple
pin groups on the board, per use case). Instead, I included an example
pin configuration into the relevant commit description.

Other controllers already present in ci20.dts do specify their pin
groups, but I think this is bad practice. Do you have particular
guidelines on this?

Pavel:
Feel free to add your Tested-by, if you still have your CI20 setup
around :) I tested this driver with two SPI mode MMC/SD card readers and
also with the spi-loopback test driver.

Cheers,
Artur

Artur Rojek (2):
  SPI: add Ingenic JZ47xx driver.
  MIPS: JZ4780: CI20: DTS: add SPI controller config

Paul Cercueil (1):
  dt-bindings: spi: Document Ingenic SPI controller bindings

 .../devicetree/bindings/spi/ingenic,spi.yaml  |  72 +++
 arch/mips/boot/dts/ingenic/ci20.dts           |   9 +-
 arch/mips/boot/dts/ingenic/jz4780.dtsi        |  44 +-
 drivers/spi/Kconfig                           |   9 +
 drivers/spi/Makefile                          |   1 +
 drivers/spi/spi-ingenic.c                     | 482 ++++++++++++++++++
 6 files changed, 602 insertions(+), 15 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/spi/ingenic,spi.yaml
 create mode 100644 drivers/spi/spi-ingenic.c

--
2.33.0

3 files changed, 492 insertions, 0 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 83e352b0c8f9..ea824b0012c6 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -406,6 +406,15 @@ config SPI_IMX
 	help
 	  This enables support for the Freescale i.MX SPI controllers.
 
+config SPI_INGENIC
+	tristate "Ingenic JZ47xx SoCs SPI controller"
+	depends on MACH_INGENIC || COMPILE_TEST
+	help
+	  This enables support for the Ingenic JZ47xx SoCs SPI controller.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called spi-ingenic.
+
 config SPI_JCORE
 	tristate "J-Core SPI Master"
 	depends on OF && (SUPERH || COMPILE_TEST)
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 699db95c8441..322952dfd279 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_SPI_HISI_KUNPENG)		+= spi-hisi-kunpeng.o
 obj-$(CONFIG_SPI_HISI_SFC_V3XX)		+= spi-hisi-sfc-v3xx.o
 obj-$(CONFIG_SPI_IMG_SPFI)		+= spi-img-spfi.o
 obj-$(CONFIG_SPI_IMX)			+= spi-imx.o
+obj-$(CONFIG_SPI_INGENIC)		+= spi-ingenic.o
 obj-$(CONFIG_SPI_LANTIQ_SSC)		+= spi-lantiq-ssc.o
 obj-$(CONFIG_SPI_JCORE)			+= spi-jcore.o
 obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
diff --git a/drivers/spi/spi-ingenic.c b/drivers/spi/spi-ingenic.c
new file mode 100644
index 000000000000..03077a7e11c8
--- /dev/null
+++ b/drivers/spi/spi-ingenic.c
@@ -0,0 +1,482 @@
+// 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");