[PATCH 0/2] Add support for PolarFire SoC's spi controllers

[PATCH 0/2] Add support for PolarFire SoC's spi controllers

[Conor Dooley]

Hey Mark,

As it says on the tin, here's a patch adding support for the spi
controllers on PolarFire SoC. The binding for them was already
added in 5.18.

Thanks,
Conor.

Conor Dooley (2):
  spi: add support for microchip fpga spi controllers
  MAINTAINERS: add spi to PolarFire SoC entry

 MAINTAINERS                      |   1 +
 drivers/spi/Kconfig              |   9 +
 drivers/spi/Makefile             |   1 +
 drivers/spi/spi-microchip-core.c | 632 +++++++++++++++++++++++++++++++
 4 files changed, 643 insertions(+)
 create mode 100644 drivers/spi/spi-microchip-core.c


base-commit: 4b0986a3613c92f4ec1bdc7f60ec66fea135991f
-- 
2.36.1

[PATCH 1/2] spi: add support for microchip fpga spi controllers

[Conor Dooley]

Add a driver for Microchip FPGA SPI controllers, specifically
supporting the "hard" controllers on PolarFire SoC.

Co-developed-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 drivers/spi/Kconfig              |   9 +
 drivers/spi/Makefile             |   1 +
 drivers/spi/spi-microchip-core.c | 632 +++++++++++++++++++++++++++++++
 3 files changed, 642 insertions(+)
 create mode 100644 drivers/spi/spi-microchip-core.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index d2815eb361c0..b142e3499bc9 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -565,6 +565,15 @@ config SPI_MESON_SPIFC
 	  This enables master mode support for the SPIFC (SPI flash
 	  controller) available in Amlogic Meson SoCs.
 
+config SPI_MICROCHIP_CORE
+	tristate "Microchip FPGA SPI controllers"
+	depends on SPI_MASTER
+	help
+	  This enables the SPI driver for Microchip FPGA SPI controllers.
+	  Say Y or M here if you want to use the "hard" controllers on
+	  PolarFire SoC.
+	  If built as a module, it will be called spi-microchip-core.
+
 config SPI_MT65XX
 	tristate "MediaTek SPI controller"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3aa28ed3f761..b1e559ff17a9 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
 obj-$(CONFIG_SPI_LP8841_RTC)		+= spi-lp8841-rtc.o
 obj-$(CONFIG_SPI_MESON_SPICC)		+= spi-meson-spicc.o
 obj-$(CONFIG_SPI_MESON_SPIFC)		+= spi-meson-spifc.o
+obj-$(CONFIG_SPI_MICROCHIP_CORE)	+= spi-microchip-core.o
 obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
 obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
 obj-$(CONFIG_SPI_MPC52xx)		+= spi-mpc52xx.o
diff --git a/drivers/spi/spi-microchip-core.c b/drivers/spi/spi-microchip-core.c
new file mode 100644
index 000000000000..5b2aee30fa04
--- /dev/null
+++ b/drivers/spi/spi-microchip-core.c
@@ -0,0 +1,632 @@
+// SPDX-License-Identifier: (GPL-2.0)
+/*
+ * Microchip CoreSPI SPI controller driver
+ *
+ * Copyright (c) 2018-2022 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Daire McNamara <daire.mcnamara@microchip.com>
+ * Author: Conor Dooley <conor.dooley@microchip.com>
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+
+#define MAX_LEN				(0xffff)
+#define MAX_CS				(8)
+#define DEFAULT_FRAMESIZE		(8)
+#define FIFO_DEPTH			(32)
+#define CLK_GEN_MODE1_MAX		(255)
+#define CLK_GEN_MODE0_MAX		(15)
+#define CLK_GEN_MIN			(0)
+#define MODE_X_MASK_SHIFT		(24)
+
+#define CONTROL_ENABLE			BIT(0)
+#define CONTROL_MASTER			BIT(1)
+#define CONTROL_RX_DATA_INT		BIT(4)
+#define CONTROL_TX_DATA_INT		BIT(5)
+#define CONTROL_RX_OVER_INT		BIT(6)
+#define CONTROL_TX_UNDER_INT		BIT(7)
+#define CONTROL_SPO			BIT(24)
+#define CONTROL_SPH			BIT(25)
+#define CONTROL_SPS			BIT(26)
+#define CONTROL_FRAMEURUN		BIT(27)
+#define CONTROL_CLKMODE			BIT(28)
+#define CONTROL_BIGFIFO			BIT(29)
+#define CONTROL_OENOFF			BIT(30)
+#define CONTROL_RESET			BIT(31)
+
+#define CONTROL_MODE_MASK		GENMASK(3, 2)
+#define  MOTOROLA_MODE			(0)
+#define CONTROL_FRAMECNT_MASK		GENMASK(23, 8)
+#define CONTROL_FRAMECNT_SHIFT		(8)
+
+#define STATUS_ACTIVE			BIT(14)
+#define STATUS_SSEL			BIT(13)
+#define STATUS_FRAMESTART		BIT(12)
+#define STATUS_TXFIFO_EMPTY_NEXT_READ	BIT(11)
+#define STATUS_TXFIFO_EMPTY		BIT(10)
+#define STATUS_TXFIFO_FULL_NEXT_WRITE	BIT(9)
+#define STATUS_TXFIFO_FULL		BIT(8)
+#define STATUS_RXFIFO_EMPTY_NEXT_READ	BIT(7)
+#define STATUS_RXFIFO_EMPTY		BIT(6)
+#define STATUS_RXFIFO_FULL_NEXT_WRITE	BIT(5)
+#define STATUS_RXFIFO_FULL		BIT(4)
+#define STATUS_TX_UNDERRUN		BIT(3)
+#define STATUS_RX_OVERFLOW		BIT(2)
+#define STATUS_RXDAT_RXED		BIT(1)
+#define STATUS_TXDAT_SENT		BIT(0)
+
+#define INT_TXDONE			BIT(0)
+#define INT_RXRDY			BIT(1)
+#define INT_RX_CHANNEL_OVERFLOW		BIT(2)
+#define INT_TX_CHANNEL_UNDERRUN		BIT(3)
+
+#define INT_ENABLE_MASK (CONTROL_RX_DATA_INT | CONTROL_TX_DATA_INT | \
+			 CONTROL_RX_OVER_INT | CONTROL_TX_UNDER_INT)
+
+#define REG_CONTROL		(0x00)
+#define REG_FRAME_SIZE		(0x04)
+#define REG_STATUS		(0x08)
+#define REG_INT_CLEAR		(0x0c)
+#define REG_RX_DATA		(0x10)
+#define REG_TX_DATA		(0x14)
+#define REG_CLK_GEN		(0x18)
+#define REG_SLAVE_SELECT	(0x1c)
+#define  SSEL_MASK		GENMASK(7, 0)
+#define  SSEL_DIRECT		BIT(8)
+#define  SSELOUT_SHIFT		9
+#define  SSELOUT		BIT(SSELOUT_SHIFT)
+#define REG_MIS			(0x20)
+#define REG_RIS			(0x24)
+#define REG_CONTROL2		(0x28)
+#define REG_COMMAND		(0x2c)
+#define REG_PKTSIZE		(0x30)
+#define REG_CMD_SIZE		(0x34)
+#define REG_HWSTATUS		(0x38)
+#define REG_STAT8		(0x3c)
+#define REG_CTRL2		(0x48)
+#define REG_FRAMESUP		(0x50)
+
+struct mchp_corespi {
+	void __iomem *regs;
+	struct clk *clk;
+	const u8 *tx_buf;
+	u8 *rx_buf;
+	u32 clk_gen; /* divider for spi output clock generated by the controller */
+	u32 clk_mode;
+	int irq;
+	int tx_len;
+	int rx_len;
+	int pending;
+};
+
+static inline u32 mchp_corespi_read(struct mchp_corespi *spi, unsigned int reg)
+{
+	return readl(spi->regs + reg);
+}
+
+static inline void mchp_corespi_write(struct mchp_corespi *spi, unsigned int reg, u32 val)
+{
+	writel(val, spi->regs + reg);
+}
+
+static inline void mchp_corespi_enable(struct mchp_corespi *spi)
+{
+	u32 control = mchp_corespi_read(spi, REG_CONTROL);
+
+	control |= CONTROL_ENABLE;
+
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static inline void mchp_corespi_disable(struct mchp_corespi *spi)
+{
+	u32 control = mchp_corespi_read(spi, REG_CONTROL);
+
+	control &= ~CONTROL_ENABLE;
+
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static inline void mchp_corespi_read_fifo(struct mchp_corespi *spi)
+{
+	u8 data;
+	int fifo_max, i = 0;
+
+	fifo_max = min(spi->rx_len, FIFO_DEPTH);
+
+	while ((i < fifo_max) && !(mchp_corespi_read(spi, REG_STATUS) & STATUS_RXFIFO_EMPTY)) {
+		data = mchp_corespi_read(spi, REG_RX_DATA);
+
+		if (spi->rx_buf)
+			*spi->rx_buf++ = data;
+		i++;
+	}
+	spi->rx_len -= i;
+	spi->pending -= i;
+}
+
+static void mchp_corespi_enable_ints(struct mchp_corespi *spi)
+{
+	u32 control, mask = INT_ENABLE_MASK;
+
+	mchp_corespi_disable(spi);
+
+	control = mchp_corespi_read(spi, REG_CONTROL);
+
+	control |= mask;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+
+	control |= CONTROL_ENABLE;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static void mchp_corespi_disable_ints(struct mchp_corespi *spi)
+{
+	u32 control, mask = INT_ENABLE_MASK;
+
+	mchp_corespi_disable(spi);
+
+	control = mchp_corespi_read(spi, REG_CONTROL);
+	control &= ~mask;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+
+	control |= CONTROL_ENABLE;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static inline void mchp_corespi_set_xfer_size(struct mchp_corespi *spi, int len)
+{
+	u32 control;
+	u16 lenpart;
+
+	/*
+	 * Disable the SPI controller. Writes to transfer length have
+	 * no effect when the controller is enabled.
+	 */
+	mchp_corespi_disable(spi);
+
+	/*
+	 * The lower 16 bits of the frame count are stored in the control reg
+	 * for legacy reasons, but the upper 16 written to a different register:
+	 * FRAMESUP. While both the upper and lower bits can be *READ* from the
+	 * FRAMESUP register, writing to the lower 16 bits is a NOP
+	 */
+	lenpart = len & 0xffff;
+
+	control = mchp_corespi_read(spi, REG_CONTROL);
+	control &= ~CONTROL_FRAMECNT_MASK;
+	control |= lenpart << CONTROL_FRAMECNT_SHIFT;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+
+	lenpart = len & 0xffff0000;
+	mchp_corespi_write(spi, REG_FRAMESUP, lenpart);
+
+	control |= CONTROL_ENABLE;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static inline void mchp_corespi_write_fifo(struct mchp_corespi *spi)
+{
+	u8 byte;
+	int fifo_max, i = 0;
+
+	fifo_max = min(spi->tx_len, FIFO_DEPTH);
+	mchp_corespi_set_xfer_size(spi, fifo_max);
+
+	while ((i < fifo_max) && !(mchp_corespi_read(spi, REG_STATUS) & STATUS_TXFIFO_FULL)) {
+		byte = spi->tx_buf ? *spi->tx_buf++ : 0xaa;
+		mchp_corespi_write(spi, REG_TX_DATA, byte);
+		i++;
+	}
+
+	spi->tx_len -= i;
+	spi->pending += i;
+}
+
+static inline void mchp_corespi_set_framesize(struct mchp_corespi *spi, int bt)
+{
+	u32 control;
+
+	/*
+	 * Disable the SPI controller. Writes to the frame size have
+	 * no effect when the controller is enabled.
+	 */
+	mchp_corespi_disable(spi);
+
+	mchp_corespi_write(spi, REG_FRAME_SIZE, bt);
+
+	control = mchp_corespi_read(spi, REG_CONTROL);
+	control |= CONTROL_ENABLE;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static void mchp_corespi_set_cs(struct spi_device *spi, bool disable)
+{
+	u32 reg;
+	struct mchp_corespi *corespi = spi_master_get_devdata(spi->master);
+
+	reg = mchp_corespi_read(corespi, REG_SLAVE_SELECT);
+	reg &= ~BIT(spi->chip_select);
+	reg |= !disable << spi->chip_select;
+
+	mchp_corespi_write(corespi, REG_SLAVE_SELECT, reg);
+}
+
+static int mchp_corespi_setup(struct spi_device *spi)
+{
+	struct mchp_corespi *corespi = spi_master_get_devdata(spi->master);
+	u32 reg;
+
+	/*
+	 * Active high slaves need to be specifically set to their inactive
+	 * states during probe by adding them to the "control group" & thus
+	 * driving their select line low.
+	 */
+	if (spi->mode & SPI_CS_HIGH) {
+		reg = mchp_corespi_read(corespi, REG_SLAVE_SELECT);
+		reg |= BIT(spi->chip_select);
+		mchp_corespi_write(corespi, REG_SLAVE_SELECT, reg);
+	}
+	return 0;
+}
+
+static void mchp_corespi_init(struct spi_master *master, struct mchp_corespi *spi)
+{
+	unsigned long clk_hz;
+	u32 control = mchp_corespi_read(spi, REG_CONTROL);
+
+	control |= CONTROL_MASTER;
+
+	control &= ~CONTROL_MODE_MASK;
+	control |= MOTOROLA_MODE;
+
+	mchp_corespi_set_framesize(spi, DEFAULT_FRAMESIZE);
+
+	/* max. possible spi clock rate is the apb clock rate */
+	clk_hz = clk_get_rate(spi->clk);
+	master->max_speed_hz = clk_hz;
+
+	/*
+	 * The controller must be configured so that it doesn't remove Chip
+	 * Select until the entire message has been transferred, even if at
+	 * some points TX FIFO becomes empty.
+	 *
+	 * BIGFIFO mode is also enabled, which sets the fifo depth to 32 frames
+	 * for the 8 bit transfers that this driver uses.
+	 */
+	control = mchp_corespi_read(spi, REG_CONTROL);
+	control |= CONTROL_SPS | CONTROL_BIGFIFO;
+
+	mchp_corespi_write(spi, REG_CONTROL, control);
+
+	mchp_corespi_enable_ints(spi);
+
+	/*
+	 * It is required to enable direct mode, otherwise control over the chip
+	 * select is relinquished to the hardware. SSELOUT is enabled too so we
+	 * can deal with active high slaves.
+	 */
+	mchp_corespi_write(spi, REG_SLAVE_SELECT, SSELOUT | SSEL_DIRECT);
+
+	control = mchp_corespi_read(spi, REG_CONTROL);
+
+	control &= ~CONTROL_RESET;
+	control |= CONTROL_ENABLE;
+
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static inline void mchp_corespi_set_clk_gen(struct mchp_corespi *spi)
+{
+	u32 control;
+
+	mchp_corespi_disable(spi);
+
+	control = mchp_corespi_read(spi, REG_CONTROL);
+	if (spi->clk_mode)
+		control |= CONTROL_CLKMODE;
+	else
+		control &= ~CONTROL_CLKMODE;
+
+	mchp_corespi_write(spi, REG_CLK_GEN, spi->clk_gen);
+	mchp_corespi_write(spi, REG_CONTROL, control);
+	mchp_corespi_write(spi, REG_CONTROL, control | CONTROL_ENABLE);
+}
+
+static inline void mchp_corespi_set_mode(struct mchp_corespi *spi, unsigned int mode)
+{
+	u32 control, mode_val;
+
+	switch (mode & SPI_MODE_X_MASK) {
+	case SPI_MODE_0:
+		mode_val = 0;
+		break;
+	case SPI_MODE_1:
+		mode_val = CONTROL_SPH;
+		break;
+	case SPI_MODE_2:
+		mode_val = CONTROL_SPO;
+		break;
+	case SPI_MODE_3:
+		mode_val = CONTROL_SPH | CONTROL_SPO;
+		break;
+	}
+
+	/*
+	 * Disable the SPI controller. Writes to the frame size have
+	 * no effect when the controller is enabled.
+	 */
+	mchp_corespi_disable(spi);
+
+	control = mchp_corespi_read(spi, REG_CONTROL);
+	control &= ~(SPI_MODE_X_MASK << MODE_X_MASK_SHIFT);
+	control |= mode_val;
+
+	mchp_corespi_write(spi, REG_CONTROL, control);
+
+	control |= CONTROL_ENABLE;
+	mchp_corespi_write(spi, REG_CONTROL, control);
+}
+
+static irqreturn_t mchp_corespi_interrupt(int irq, void *dev_id)
+{
+	struct spi_master *master = dev_id;
+	struct mchp_corespi *spi = spi_master_get_devdata(master);
+	u32 intfield = mchp_corespi_read(spi, REG_MIS) & 0xf;
+	bool finalise = false;
+
+	/* Interrupt line may be shared and not for us at all */
+	if (intfield == 0)
+		return IRQ_NONE;
+
+	if (intfield & INT_TXDONE) {
+		mchp_corespi_write(spi, REG_INT_CLEAR, INT_TXDONE);
+
+		if (spi->rx_len)
+			mchp_corespi_read_fifo(spi);
+
+		if (spi->tx_len)
+			mchp_corespi_write_fifo(spi);
+
+		if (!spi->rx_len)
+			finalise = true;
+	}
+
+	if (intfield & INT_RXRDY)
+		mchp_corespi_write(spi, REG_INT_CLEAR, INT_RXRDY);
+
+	if (intfield & INT_RX_CHANNEL_OVERFLOW) {
+		mchp_corespi_write(spi, REG_INT_CLEAR, INT_RX_CHANNEL_OVERFLOW);
+		finalise = true;
+		dev_err(&master->dev,
+			"%s: RX OVERFLOW: rxlen: %d, txlen: %d\n", __func__,
+			spi->rx_len, spi->tx_len);
+	}
+
+	if (intfield & INT_TX_CHANNEL_UNDERRUN) {
+		mchp_corespi_write(spi, REG_INT_CLEAR, INT_TX_CHANNEL_UNDERRUN);
+		finalise = true;
+		dev_err(&master->dev,
+			"%s: TX UNDERFLOW: rxlen: %d, txlen: %d\n", __func__,
+			spi->rx_len, spi->tx_len);
+	}
+
+	if (finalise)
+		spi_finalize_current_transfer(master);
+
+	return IRQ_HANDLED;
+}
+
+static int mchp_corespi_calculate_clkgen(struct mchp_corespi *spi,
+					 unsigned long target_hz)
+{
+	unsigned long clk_hz, spi_hz, clk_gen;
+
+	clk_hz = clk_get_rate(spi->clk);
+	spi_hz = min(target_hz, clk_hz);
+
+	/*
+	 * There are two possible clock modes for the controller generated
+	 * clock's division ratio:
+	 * CLK_MODE = 0: 1 / (2^(CLK_GEN + 1)) where CLK_GEN = 0 to 15.
+	 * CLK_MODE = 1: 1 / (2 * CLK_GEN + 1) where CLK_GEN = 0 to 255.
+	 * First try mode 1, fall back to 0 and if we have tried both modes and
+	 * we /still/ can't get a good setting, we then throw the toys out of
+	 * the pram and give up
+	 * clk_gen is the register name for the clock divider on MPFS.
+	 */
+	clk_gen = DIV_ROUND_UP(clk_hz, 2 * spi_hz) - 1;
+	if (clk_gen > CLK_GEN_MODE1_MAX || clk_gen <= CLK_GEN_MIN) {
+		clk_gen = DIV_ROUND_UP(clk_hz, spi_hz);
+		clk_gen = fls(clk_gen) - 1;
+
+		if (clk_gen > CLK_GEN_MODE0_MAX)
+			return -EINVAL;
+
+		spi->clk_mode = 0;
+	} else {
+		spi->clk_mode = 1;
+	}
+
+	spi->clk_gen = clk_gen;
+	return 0;
+}
+
+static int mchp_corespi_transfer_one(struct spi_master *master,
+				     struct spi_device *spi_dev,
+				     struct spi_transfer *xfer)
+{
+	struct mchp_corespi *spi = spi_master_get_devdata(master);
+	int ret;
+
+	ret = mchp_corespi_calculate_clkgen(spi, (unsigned long)xfer->speed_hz);
+	if (ret) {
+		dev_err(&master->dev, "failed to set clk_gen for target %u Hz\n", xfer->speed_hz);
+		return ret;
+	}
+
+	mchp_corespi_set_clk_gen(spi);
+
+	spi->tx_buf = xfer->tx_buf;
+	spi->rx_buf = xfer->rx_buf;
+	spi->tx_len = xfer->len;
+	spi->rx_len = xfer->len;
+	spi->pending = 0;
+
+	mchp_corespi_set_xfer_size(spi, (spi->tx_len > FIFO_DEPTH)
+				   ? FIFO_DEPTH : spi->tx_len);
+
+	if (spi->tx_len)
+		mchp_corespi_write_fifo(spi);
+	return 1;
+}
+
+static int mchp_corespi_prepare_message(struct spi_master *master,
+					struct spi_message *msg)
+{
+	struct spi_device *spi_dev = msg->spi;
+	struct mchp_corespi *spi = spi_master_get_devdata(master);
+
+	mchp_corespi_set_framesize(spi, DEFAULT_FRAMESIZE);
+	mchp_corespi_set_mode(spi, spi_dev->mode);
+
+	return 0;
+}
+
+static int mchp_corespi_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct mchp_corespi *spi;
+	struct resource *res;
+	u32 num_cs;
+	int ret = 0;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*spi));
+	if (!master)
+		return dev_err_probe(&pdev->dev, -ENOMEM,
+				     "unable to allocate master for SPI controller\n");
+
+	platform_set_drvdata(pdev, master);
+
+	if (of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs))
+		num_cs = MAX_CS;
+
+	master->num_chipselect = num_cs;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+	master->setup = mchp_corespi_setup;
+	master->bits_per_word_mask = SPI_BPW_MASK(8);
+	master->transfer_one = mchp_corespi_transfer_one;
+	master->prepare_message = mchp_corespi_prepare_message;
+	master->set_cs = mchp_corespi_set_cs;
+	master->dev.of_node = pdev->dev.of_node;
+
+	spi = spi_master_get_devdata(master);
+
+	spi->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(spi->regs)) {
+		ret = PTR_ERR(spi->regs);
+		goto error_release_master;
+	}
+
+	spi->irq = platform_get_irq(pdev, 0);
+	if (spi->irq <= 0) {
+		dev_err(&pdev->dev, "invalid IRQ %d for SPI controller\n", spi->irq);
+		ret = spi->irq;
+		goto error_release_master;
+	}
+
+	ret = devm_request_irq(&pdev->dev, spi->irq, mchp_corespi_interrupt,
+			       IRQF_SHARED, dev_name(&pdev->dev), master);
+	if (ret) {
+		dev_err(&pdev->dev, "could not request irq: %d\n", ret);
+		goto error_release_master;
+	}
+
+	spi->clk = devm_clk_get(&pdev->dev, NULL);
+	if (!spi->clk || IS_ERR(spi->clk)) {
+		ret = PTR_ERR(spi->clk);
+		dev_err(&pdev->dev, "could not get clk: %d\n", ret);
+		goto error_release_master;
+	}
+
+	ret = clk_prepare_enable(spi->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable clock\n");
+		goto error_release_master;
+	}
+
+	mchp_corespi_init(master, spi);
+
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"unable to register master for SPI controller\n");
+		goto error_release_hardware;
+	}
+
+	dev_info(&pdev->dev, "Registered SPI controller %d\n", master->bus_num);
+
+	return 0;
+
+error_release_hardware:
+	mchp_corespi_disable(spi);
+	clk_prepare_enable(spi->clk);
+error_release_master:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int mchp_corespi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master  = platform_get_drvdata(pdev);
+	struct mchp_corespi *spi = spi_master_get_devdata(master);
+
+	mchp_corespi_disable_ints(spi);
+	spi_unregister_master(master);
+	spi_master_put(master);
+	clk_disable_unprepare(spi->clk);
+	mchp_corespi_disable(spi);
+
+	return 0;
+}
+
+#define MICROCHIP_SPI_PM_OPS (NULL)
+
+/*
+ * Platform driver data structure
+ */
+
+#if defined(CONFIG_OF)
+static const struct of_device_id mchp_corespi_dt_ids[] = {
+	{ .compatible = "microchip,mpfs-spi" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mchp_corespi_dt_ids);
+#endif
+
+static struct platform_driver mchp_corespi_driver = {
+	.probe = mchp_corespi_probe,
+	.driver = {
+		.name = "microchip-corespi",
+		.pm = MICROCHIP_SPI_PM_OPS,
+		.of_match_table = of_match_ptr(mchp_corespi_dt_ids),
+		.owner = THIS_MODULE,
+	},
+	.remove = mchp_corespi_remove,
+};
+module_platform_driver(mchp_corespi_driver);
+MODULE_DESCRIPTION("Microchip coreSPI SPI controller driver");
+MODULE_AUTHOR("Daire McNamara <daire.mcnamara@microchip.com>");
+MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
+MODULE_LICENSE("GPL");
-- 
2.36.1

[PATCH 2/2] MAINTAINERS: add spi to PolarFire SoC entry

[Conor Dooley]

Add the newly introduced spi driver to the existing PolarFire SoC entry.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index f468864fd268..279a25065942 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16955,6 +16955,7 @@ S:	Supported
 F:	arch/riscv/boot/dts/microchip/
 F:	drivers/mailbox/mailbox-mpfs.c
 F:	drivers/soc/microchip/
+F:	drivers/spi/spi-microchip-core.c
 F:	include/soc/microchip/mpfs.h
 
 RNBD BLOCK DRIVERS
-- 
2.36.1

Re: [PATCH 0/2] Add support for PolarFire SoC's spi controllers

[Mark Brown]

On Tue, 7 Jun 2022 08:38:32 +0100, Conor Dooley wrote:
> Hey Mark,
> 
> As it says on the tin, here's a patch adding support for the spi
> controllers on PolarFire SoC. The binding for them was already
> added in 5.18.
> 
> Thanks,
> Conor.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/2] spi: add support for microchip fpga spi controllers
      commit: 9ac8d17694b66d54b13e9718b25c14ca36dbebbd
[2/2] MAINTAINERS: add spi to PolarFire SoC entry
      commit: f303c6b26cede1aa137dc3e10eee78a80cde9999

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark