[PATCH 9/9] spi: amd: Add support for latest platform

[Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>]

Add support for AMDI0062 controllers

Signed-off-by: Nehal Bakulchandra Shah <Nehal-Bakulchandra.shah@xxxxxxx>
Signed-off-by: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
---
 drivers/spi/spi-amd.c | 127 +++++++++++++++++++++++++++++++++---------
 1 file changed, 100 insertions(+), 27 deletions(-)

diff --git a/drivers/spi/spi-amd.c b/drivers/spi/spi-amd.c
index b6308733265e..cd0b38ead150 100644
--- a/drivers/spi/spi-amd.c
+++ b/drivers/spi/spi-amd.c
@@ -2,9 +2,10 @@
 //
 // AMD SPI controller driver
 //
-// Copyright (c) 2020, Advanced Micro Devices, Inc.
+// Copyright (c) 2020-2021, Advanced Micro Devices, Inc.
 //
 // Authors: Sanjay R Mehta <sanju.mehta@xxxxxxx>
+//          Nehal Bakulchandra Shah <nehal-bakulchandra.shah@xxxxxxx>
 //          Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
 
 #include <linux/acpi.h>
@@ -15,32 +16,46 @@
 #include <linux/spi/spi.h>
 #include <linux/iopoll.h>
 
-#define AMD_SPI_CTRL0_REG	0x00
-#define AMD_SPI_EXEC_CMD	BIT(16)
-#define AMD_SPI_FIFO_CLEAR	BIT(20)
-#define AMD_SPI_BUSY		BIT(31)
+#define AMD_SPI_CTRL0_REG		0x00
+#define AMD_SPI_EXEC_CMD		BIT(16)
+#define AMD_SPI_FIFO_CLEAR		BIT(20)
+#define AMD_SPI_BUSY			BIT(31)
+#define AMD_SPI_ENABLE_REG		0x20
 
-#define AMD_SPI_OPCODE_MASK	0xFF
+#define AMD_SPI_DUMMY_CYCL_REG		0x32
+#define AMD_SPI_OPCODE_REG		0x45
+#define AMD_SPI_CMD_TRIGGER_REG		0x47
+#define AMD_SPI_TRIGGER_CMD		BIT(7)
+#define AMD_SPI_OPCODE_MASK		0xFF
 
-#define AMD_SPI_ALT_CS_REG	0x1D
-#define AMD_SPI_ALT_CS_MASK	0x3
+#define AMD_SPI_ALT_CS_REG		0x1D
+#define AMD_SPI_ALT_CS_MASK		GENMASK(1, 0)
 
-#define AMD_SPI_FIFO_BASE	0x80
-#define AMD_SPI_TX_COUNT_REG	0x48
-#define AMD_SPI_RX_COUNT_REG	0x4B
-#define AMD_SPI_STATUS_REG	0x4C
+#define AMD_SPI_FIFO_BASE		0x80
+#define AMD_SPI_TX_COUNT_REG		0x48
+#define AMD_SPI_RX_COUNT_REG		0x4B
+#define AMD_SPI_STATUS_REG		0x4C
 
-#define AMD_SPI_FIFO_SIZE	70
-#define AMD_SPI_MEM_SIZE	200
+#define AMD_SPI_FIFO_SIZE		70
+#define AMD_SPI_MEM_SIZE		200
 
 /* M_CMD OP codes for SPI */
-#define AMD_SPI_XFER_TX		1
-#define AMD_SPI_XFER_RX		2
+#define AMD_SPI_XFER_TX			1
+#define AMD_SPI_XFER_RX			2
 
 struct amd_spi {
 	void __iomem *io_remap_addr;
 	unsigned long io_base_addr;
 	u32 rom_addr;
+	const struct amd_spi_devtype_data *devtype_data;
+	struct spi_device *spi_dev;
+	struct spi_master *master;
+};
+
+struct amd_spi_devtype_data {
+	u8 version;
+	int (*exec_op)(struct amd_spi *amd_spi);
+	void (*set_op)(struct amd_spi *amd_spi, u8 cmd_opcode);
 };
 
 static inline u8 amd_spi_readreg8(struct amd_spi *amd_spi, int idx)
@@ -84,16 +99,26 @@ static void amd_spi_select_chip(struct amd_spi *amd_spi, u8 cs)
 	amd_spi_setclear_reg8(amd_spi, AMD_SPI_ALT_CS_REG, cs, AMD_SPI_ALT_CS_MASK);
 }
 
+static inline void amd_spi_clear_chip(struct amd_spi *amd_spi, u8 chip_select)
+{
+	amd_spi_writereg8(amd_spi, AMD_SPI_ALT_CS_REG, chip_select & ~AMD_SPI_ALT_CS_MASK);
+}
+
 static void amd_spi_clear_fifo_ptr(struct amd_spi *amd_spi)
 {
 	amd_spi_setclear_reg32(amd_spi, AMD_SPI_CTRL0_REG, AMD_SPI_FIFO_CLEAR, AMD_SPI_FIFO_CLEAR);
 }
 
-static void amd_spi_set_opcode(struct amd_spi *amd_spi, u8 cmd_opcode)
+static void amd_spi_set_opcode_v1(struct amd_spi *amd_spi, u8 cmd_opcode)
 {
 	amd_spi_setclear_reg32(amd_spi, AMD_SPI_CTRL0_REG, cmd_opcode, AMD_SPI_OPCODE_MASK);
 }
 
+static void amd_spi_set_opcode_v2(struct amd_spi *amd_spi, u8 cmd_opcode)
+{
+	amd_spi_writereg8(amd_spi, AMD_SPI_OPCODE_REG, cmd_opcode);
+}
+
 static inline void amd_spi_set_rx_count(struct amd_spi *amd_spi, u8 rx_count)
 {
 	amd_spi_setclear_reg8(amd_spi, AMD_SPI_RX_COUNT_REG, rx_count, 0xff);
@@ -104,7 +129,7 @@ static inline void amd_spi_set_tx_count(struct amd_spi *amd_spi, u8 tx_count)
 	amd_spi_setclear_reg8(amd_spi, AMD_SPI_TX_COUNT_REG, tx_count, 0xff);
 }
 
-static int amd_spi_busy_wait(struct amd_spi *amd_spi)
+static int amd_spi_busy_wait_v1(struct amd_spi *amd_spi)
 {
 	u32 val;
 
@@ -112,17 +137,39 @@ static int amd_spi_busy_wait(struct amd_spi *amd_spi)
 				 !(val & AMD_SPI_BUSY), 10, 100000);
 }
 
-static int amd_spi_execute_opcode(struct amd_spi *amd_spi)
+static int amd_spi_execute_opcode_v1(struct amd_spi *amd_spi)
 {
-	int ret = amd_spi_busy_wait(amd_spi);
+	int ret;
 
+	ret = amd_spi_busy_wait_v1(amd_spi);
 	if (ret)
 		return ret;
 
-	/* Set ExecuteOpCode bit in the CTRL0 register */
 	amd_spi_setclear_reg32(amd_spi, AMD_SPI_CTRL0_REG, AMD_SPI_EXEC_CMD, AMD_SPI_EXEC_CMD);
 
-	return amd_spi_busy_wait(amd_spi);
+	return amd_spi_busy_wait_v1(amd_spi);
+}
+
+static int amd_spi_busy_wait_v2(struct amd_spi *amd_spi)
+{
+	u32 val;
+
+	return readl_poll_timeout(amd_spi->io_remap_addr + AMD_SPI_STATUS_REG, val,
+				 !(val & AMD_SPI_BUSY), 10, 1000);
+}
+
+static int amd_spi_execute_opcode_v2(struct amd_spi *amd_spi)
+{
+	int ret;
+
+	ret = amd_spi_busy_wait_v2(amd_spi);
+	if (ret)
+		return ret;
+
+	amd_spi_setclear_reg8(amd_spi, AMD_SPI_CMD_TRIGGER_REG, AMD_SPI_TRIGGER_CMD,
+			      AMD_SPI_TRIGGER_CMD);
+
+	return amd_spi_busy_wait_v2(amd_spi);
 }
 
 static int amd_spi_master_setup(struct spi_device *spi)
@@ -138,6 +185,7 @@ static int amd_spi_double_write(struct spi_master *mst, u8 *tx1_buf, u8 tx1_len,
 				u8 tx2_len)
 {
 	struct amd_spi *amd_spi = spi_master_get_devdata(mst);
+	const struct amd_spi_devtype_data *priv = amd_spi->devtype_data;
 	int i, ret;
 
 	if (tx1_len + tx2_len > AMD_SPI_FIFO_SIZE)
@@ -146,7 +194,7 @@ static int amd_spi_double_write(struct spi_master *mst, u8 *tx1_buf, u8 tx1_len,
 	amd_spi_clear_fifo_ptr(amd_spi);
 	amd_spi_set_rx_count(amd_spi, 0);
 
-	amd_spi_set_opcode(amd_spi, tx1_buf[0]);
+	priv->set_op(amd_spi, tx1_buf[0]);
 	tx1_len--;
 	tx1_buf++;
 
@@ -157,7 +205,7 @@ static int amd_spi_double_write(struct spi_master *mst, u8 *tx1_buf, u8 tx1_len,
 		amd_spi_writereg8(amd_spi, (u8)(AMD_SPI_FIFO_BASE + tx1_len + i), tx2_buf[i]);
 
 	amd_spi_set_tx_count(amd_spi, tx1_len + tx2_len);
-	ret = amd_spi_execute_opcode(amd_spi);
+	ret = priv->exec_op(amd_spi);
 
 	return ret ? ret : tx1_len + 1 + tx2_len;
 }
@@ -165,6 +213,7 @@ static int amd_spi_double_write(struct spi_master *mst, u8 *tx1_buf, u8 tx1_len,
 static int amd_spi_write_read(struct spi_master *mst, u8 *tx_buf, u8 tx_len, u8 *rx_buf, u8 rx_len)
 {
 	struct amd_spi *amd_spi = spi_master_get_devdata(mst);
+	const struct amd_spi_devtype_data *priv = amd_spi->devtype_data;
 	int i, ret;
 
 	if (tx_len + rx_len > AMD_SPI_FIFO_SIZE)
@@ -174,7 +223,7 @@ static int amd_spi_write_read(struct spi_master *mst, u8 *tx_buf, u8 tx_len, u8
 
 	if (tx_buf) {
 		/* Take the first byte to be written and set as opcode */
-		amd_spi_set_opcode(amd_spi, tx_buf[0]);
+		priv->set_op(amd_spi, tx_buf[0]);
 		/* Set TX count as the number of bytes to be written less one (opcode byte) */
 		tx_len--;
 		tx_buf++;
@@ -191,7 +240,7 @@ static int amd_spi_write_read(struct spi_master *mst, u8 *tx_buf, u8 tx_len, u8
 	amd_spi_set_rx_count(amd_spi, rx_buf ? rx_len : 0);
 
 	/* Trigger the transfer by executing the opcode */
-	ret = amd_spi_execute_opcode(amd_spi);
+	ret = priv->exec_op(amd_spi);
 	if (ret)
 		return ret;
 
@@ -274,6 +323,9 @@ static int amd_spi_master_transfer(struct spi_master *mst, struct spi_message *m
 	msg->status = ret;
 	spi_finalize_current_message(mst);
 
+	if (amd_spi->devtype_data->version)
+		amd_spi_clear_chip(amd_spi, msg->spi->chip_select);
+
 	return ret;
 }
 
@@ -305,6 +357,12 @@ static int amd_spi_probe(struct platform_device *pdev)
 	}
 	dev_dbg(dev, "io_remap_address: %p\n", amd_spi->io_remap_addr);
 
+	amd_spi->devtype_data = device_get_match_data(dev);
+	if (!amd_spi->devtype_data) {
+		err = -ENODEV;
+		goto err_free_master;
+	}
+
 	/* Initialize the spi_master fields */
 	master->bus_num = 0;
 	master->num_chipselect = 4;
@@ -329,9 +387,23 @@ static int amd_spi_probe(struct platform_device *pdev)
 	return err;
 }
 
+static const struct amd_spi_devtype_data spi_v1 = {
+	.exec_op	= amd_spi_execute_opcode_v1,
+	.set_op		= amd_spi_set_opcode_v1,
+};
+
+static const struct amd_spi_devtype_data spi_v2 = {
+	.version	= 1,
+	.exec_op	= amd_spi_execute_opcode_v2,
+	.set_op		= amd_spi_set_opcode_v2,
+};
+
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id spi_acpi_match[] = {
-	{ "AMDI0061", 0 },
+	{ "AMDI0061",
+	.driver_data = (kernel_ulong_t)&spi_v1 },
+	{ "AMDI0062",
+	.driver_data = (kernel_ulong_t)&spi_v2 },
 	{},
 };
 MODULE_DEVICE_TABLE(acpi, spi_acpi_match);
@@ -349,4 +421,5 @@ module_platform_driver(amd_spi_driver);
 
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_AUTHOR("Sanjay Mehta <sanju.mehta@xxxxxxx>");
+MODULE_AUTHOR("Nehal Bakulchandra Shah <nehal-bakulchandra.shah@xxxxxxx>");
 MODULE_DESCRIPTION("AMD SPI Master Controller Driver");
-- 
2.33.0