[linux-2.6-block.git] / drivers / spi / spi-amd.c

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
//
// AMD SPI controller driver
//
// Copyright (c) 2020, Advanced Micro Devices, Inc.
//
// Author: Sanjay R Mehta <sanju.mehta@amd.com>

#include <linux/acpi.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/spi/spi.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_OPCODE_MASK	0xFF

#define AMD_SPI_ALT_CS_REG	0x1D
#define AMD_SPI_ALT_CS_MASK	0x3

#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_MEM_SIZE	200

/* M_CMD OP codes for SPI */
#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;
	u8 chip_select;
};

static inline u8 amd_spi_readreg8(struct spi_master *master, int idx)
{
	struct amd_spi *amd_spi = spi_master_get_devdata(master);

	return ioread8((u8 __iomem *)amd_spi->io_remap_addr + idx);
}

static inline void amd_spi_writereg8(struct spi_master *master, int idx,
				     u8 val)
{
	struct amd_spi *amd_spi = spi_master_get_devdata(master);

	iowrite8(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx));
}

static inline void amd_spi_setclear_reg8(struct spi_master *master, int idx,
					 u8 set, u8 clear)
{
	u8 tmp = amd_spi_readreg8(master, idx);

	tmp = (tmp & ~clear) | set;
	amd_spi_writereg8(master, idx, tmp);
}

static inline u32 amd_spi_readreg32(struct spi_master *master, int idx)
{
	struct amd_spi *amd_spi = spi_master_get_devdata(master);

	return ioread32((u8 __iomem *)amd_spi->io_remap_addr + idx);
}

static inline void amd_spi_writereg32(struct spi_master *master, int idx,
				      u32 val)
{
	struct amd_spi *amd_spi = spi_master_get_devdata(master);

	iowrite32(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx));
}

static inline void amd_spi_setclear_reg32(struct spi_master *master, int idx,
					  u32 set, u32 clear)
{
	u32 tmp = amd_spi_readreg32(master, idx);

	tmp = (tmp & ~clear) | set;
	amd_spi_writereg32(master, idx, tmp);
}

static void amd_spi_select_chip(struct spi_master *master)
{
	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	u8 chip_select = amd_spi->chip_select;

	amd_spi_setclear_reg8(master, AMD_SPI_ALT_CS_REG, chip_select,
			      AMD_SPI_ALT_CS_MASK);
}

static void amd_spi_clear_fifo_ptr(struct spi_master *master)
{
	amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, AMD_SPI_FIFO_CLEAR,
			       AMD_SPI_FIFO_CLEAR);
}

static void amd_spi_set_opcode(struct spi_master *master, u8 cmd_opcode)
{
	amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, cmd_opcode,
			       AMD_SPI_OPCODE_MASK);
}

static inline void amd_spi_set_rx_count(struct spi_master *master,
					u8 rx_count)
{
	amd_spi_setclear_reg8(master, AMD_SPI_RX_COUNT_REG, rx_count, 0xff);
}

static inline void amd_spi_set_tx_count(struct spi_master *master,
					u8 tx_count)
{
	amd_spi_setclear_reg8(master, AMD_SPI_TX_COUNT_REG, tx_count, 0xff);
}

static inline int amd_spi_busy_wait(struct amd_spi *amd_spi)
{
	bool spi_busy;
	int timeout = 100000;

	/* poll for SPI bus to become idle */
	spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
		    AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
	while (spi_busy) {
		usleep_range(10, 20);
		if (timeout-- < 0)
			return -ETIMEDOUT;

		spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
			    AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
	}

	return 0;
}

static void amd_spi_execute_opcode(struct spi_master *master)
{
	struct amd_spi *amd_spi = spi_master_get_devdata(master);

	/* Set ExecuteOpCode bit in the CTRL0 register */
	amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, AMD_SPI_EXEC_CMD,
			       AMD_SPI_EXEC_CMD);

	amd_spi_busy_wait(amd_spi);
}

static int amd_spi_master_setup(struct spi_device *spi)
{
	struct spi_master *master = spi->master;

	amd_spi_clear_fifo_ptr(master);

	return 0;
}

static inline int amd_spi_fifo_xfer(struct amd_spi *amd_spi,
				    struct spi_master *master,
				    struct spi_message *message)
{
	struct spi_transfer *xfer = NULL;
	u8 cmd_opcode;
	u8 *buf = NULL;
	u32 m_cmd = 0;
	u32 i = 0;
	u32 tx_len = 0, rx_len = 0;

	list_for_each_entry(xfer, &message->transfers,
			    transfer_list) {
		if (xfer->rx_buf)
			m_cmd = AMD_SPI_XFER_RX;
		if (xfer->tx_buf)
			m_cmd = AMD_SPI_XFER_TX;

		if (m_cmd & AMD_SPI_XFER_TX) {
			buf = (u8 *)xfer->tx_buf;
			tx_len = xfer->len - 1;
			cmd_opcode = *(u8 *)xfer->tx_buf;
			buf++;
			amd_spi_set_opcode(master, cmd_opcode);

			/* Write data into the FIFO. */
			for (i = 0; i < tx_len; i++) {
				iowrite8(buf[i],
					 ((u8 __iomem *)amd_spi->io_remap_addr +
					 AMD_SPI_FIFO_BASE + i));
			}

			amd_spi_set_tx_count(master, tx_len);
			amd_spi_clear_fifo_ptr(master);
			/* Execute command */
			amd_spi_execute_opcode(master);
		}
		if (m_cmd & AMD_SPI_XFER_RX) {
			/*
			 * Store no. of bytes to be received from
			 * FIFO
			 */
			rx_len = xfer->len;
			buf = (u8 *)xfer->rx_buf;
			amd_spi_set_rx_count(master, rx_len);
			amd_spi_clear_fifo_ptr(master);
			/* Execute command */
			amd_spi_execute_opcode(master);
			/* Read data from FIFO to receive buffer  */
			for (i = 0; i < rx_len; i++)
				buf[i] = amd_spi_readreg8(master,
							  AMD_SPI_FIFO_BASE +
							  tx_len + i);
		}
	}

	/* Update statistics */
	message->actual_length = tx_len + rx_len + 1;
	/* complete the transaction */
	message->status = 0;
	spi_finalize_current_message(master);

	return 0;
}

static int amd_spi_master_transfer(struct spi_master *master,
				   struct spi_message *msg)
{
	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	struct spi_device *spi = msg->spi;

	amd_spi->chip_select = spi->chip_select;
	amd_spi_select_chip(master);

	/*
	 * Extract spi_transfers from the spi message and
	 * program the controller.
	 */
	amd_spi_fifo_xfer(amd_spi, master, msg);

	return 0;
}

static int amd_spi_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct spi_master *master;
	struct amd_spi *amd_spi;
	int err = 0;

	/* Allocate storage for spi_master and driver private data */
	master = spi_alloc_master(dev, sizeof(struct amd_spi));
	if (!master) {
		dev_err(dev, "Error allocating SPI master\n");
		return -ENOMEM;
	}

	amd_spi = spi_master_get_devdata(master);
	amd_spi->io_remap_addr = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(amd_spi->io_remap_addr)) {
		err = PTR_ERR(amd_spi->io_remap_addr);
		dev_err(dev, "error %d ioremap of SPI registers failed\n", err);
		goto err_free_master;
	}
	dev_dbg(dev, "io_remap_address: %p\n", amd_spi->io_remap_addr);

	/* Initialize the spi_master fields */
	master->bus_num = 0;
	master->num_chipselect = 4;
	master->mode_bits = 0;
	master->flags = SPI_MASTER_HALF_DUPLEX;
	master->setup = amd_spi_master_setup;
	master->transfer_one_message = amd_spi_master_transfer;

	/* Register the controller with SPI framework */
	err = devm_spi_register_master(dev, master);
	if (err) {
		dev_err(dev, "error %d registering SPI controller\n", err);
		goto err_free_master;
	}

	return 0;

err_free_master:
	spi_master_put(master);

	return err;
}

#ifdef CONFIG_ACPI
static const struct acpi_device_id spi_acpi_match[] = {
	{ "AMDI0061", 0 },
	{},
};
MODULE_DEVICE_TABLE(acpi, spi_acpi_match);
#endif

static struct platform_driver amd_spi_driver = {
	.driver = {
		.name = "amd_spi",
		.acpi_match_table = ACPI_PTR(spi_acpi_match),
	},
	.probe = amd_spi_probe,
};

module_platform_driver(amd_spi_driver);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Sanjay Mehta <sanju.mehta@amd.com>");
MODULE_DESCRIPTION("AMD SPI Master Controller Driver");
Commit	Line	Data
bbb336f3 SM	1	// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
	2	//
	3	// AMD SPI controller driver
	4	//
	5	// Copyright (c) 2020, Advanced Micro Devices, Inc.
	6	//
	7	// Author: Sanjay R Mehta <sanju.mehta@amd.com>
	8
	9	#include <linux/acpi.h>
	10	#include <linux/init.h>
	11	#include <linux/module.h>
	12	#include <linux/platform_device.h>
	13	#include <linux/delay.h>
	14	#include <linux/spi/spi.h>
	15
	16	#define AMD_SPI_CTRL0_REG 0x00
	17	#define AMD_SPI_EXEC_CMD BIT(16)
	18	#define AMD_SPI_FIFO_CLEAR BIT(20)
	19	#define AMD_SPI_BUSY BIT(31)
	20
	21	#define AMD_SPI_OPCODE_MASK 0xFF
	22
	23	#define AMD_SPI_ALT_CS_REG 0x1D
	24	#define AMD_SPI_ALT_CS_MASK 0x3
	25
	26	#define AMD_SPI_FIFO_BASE 0x80
	27	#define AMD_SPI_TX_COUNT_REG 0x48
	28	#define AMD_SPI_RX_COUNT_REG 0x4B
	29	#define AMD_SPI_STATUS_REG 0x4C
	30
	31	#define AMD_SPI_MEM_SIZE 200
	32
	33	/* M_CMD OP codes for SPI */
	34	#define AMD_SPI_XFER_TX 1
	35	#define AMD_SPI_XFER_RX 2
	36
	37	struct amd_spi {
	38	void __iomem *io_remap_addr;
	39	unsigned long io_base_addr;
	40	u32 rom_addr;
bbb336f3 SM	41	u8 chip_select;
	42	};
	43
	44	static inline u8 amd_spi_readreg8(struct spi_master *master, int idx)
	45	{
	46	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	47
	48	return ioread8((u8 __iomem *)amd_spi->io_remap_addr + idx);
	49	}
	50
	51	static inline void amd_spi_writereg8(struct spi_master *master, int idx,
	52	u8 val)
	53	{
	54	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	55
	56	iowrite8(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx));
	57	}
	58
	59	static inline void amd_spi_setclear_reg8(struct spi_master *master, int idx,
	60	u8 set, u8 clear)
	61	{
	62	u8 tmp = amd_spi_readreg8(master, idx);
	63
	64	tmp = (tmp & ~clear) \| set;
	65	amd_spi_writereg8(master, idx, tmp);
	66	}
	67
	68	static inline u32 amd_spi_readreg32(struct spi_master *master, int idx)
	69	{
	70	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	71
	72	return ioread32((u8 __iomem *)amd_spi->io_remap_addr + idx);
	73	}
	74
	75	static inline void amd_spi_writereg32(struct spi_master *master, int idx,
	76	u32 val)
	77	{
	78	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	79
	80	iowrite32(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx));
	81	}
	82
	83	static inline void amd_spi_setclear_reg32(struct spi_master *master, int idx,
	84	u32 set, u32 clear)
	85	{
	86	u32 tmp = amd_spi_readreg32(master, idx);
	87
	88	tmp = (tmp & ~clear) \| set;
	89	amd_spi_writereg32(master, idx, tmp);
	90	}
	91
	92	static void amd_spi_select_chip(struct spi_master *master)
	93	{
	94	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	95	u8 chip_select = amd_spi->chip_select;
	96
	97	amd_spi_setclear_reg8(master, AMD_SPI_ALT_CS_REG, chip_select,
	98	AMD_SPI_ALT_CS_MASK);
	99	}
	100
	101	static void amd_spi_clear_fifo_ptr(struct spi_master *master)
	102	{
	103	amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, AMD_SPI_FIFO_CLEAR,
	104	AMD_SPI_FIFO_CLEAR);
105	}
106
107	static void amd_spi_set_opcode(struct spi_master *master, u8 cmd_opcode)
108	{
109	amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, cmd_opcode,
110	AMD_SPI_OPCODE_MASK);
111	}
112
113	static inline void amd_spi_set_rx_count(struct spi_master *master,
114	u8 rx_count)
115	{
116	amd_spi_setclear_reg8(master, AMD_SPI_RX_COUNT_REG, rx_count, 0xff);
117	}
118
119	static inline void amd_spi_set_tx_count(struct spi_master *master,
120	u8 tx_count)
121	{
122	amd_spi_setclear_reg8(master, AMD_SPI_TX_COUNT_REG, tx_count, 0xff);
123	}
124
125	static inline int amd_spi_busy_wait(struct amd_spi *amd_spi)
126	{
127	bool spi_busy;
128	int timeout = 100000;
129
130	/* poll for SPI bus to become idle */
131	spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
132	AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
133	while (spi_busy) {
134	usleep_range(10, 20);
135	if (timeout-- < 0)
136	return -ETIMEDOUT;
137
138	spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
139	AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
140	}
141
142	return 0;
143	}
144
145	static void amd_spi_execute_opcode(struct spi_master *master)
146	{
147	struct amd_spi *amd_spi = spi_master_get_devdata(master);
148
149	/* Set ExecuteOpCode bit in the CTRL0 register */
150	amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, AMD_SPI_EXEC_CMD,
151	AMD_SPI_EXEC_CMD);
152
153	amd_spi_busy_wait(amd_spi);
154	}
155
156	static int amd_spi_master_setup(struct spi_device *spi)
157	{
158	struct spi_master *master = spi->master;
159
160	amd_spi_clear_fifo_ptr(master);
161
162	return 0;
163	}
164
165	static inline int amd_spi_fifo_xfer(struct amd_spi *amd_spi,
36c72a58	166	struct spi_master *master,
bbb336f3 SM	167	struct spi_message *message)
bbb336f3 SM	168	{
bbb336f3	169	struct spi_transfer *xfer = NULL;
68d047cb	170	u8 cmd_opcode;
bbb336f3 SM	171	u8 *buf = NULL;
	172	u32 m_cmd = 0;
	173	u32 i = 0;
	174	u32 tx_len = 0, rx_len = 0;
	175
	176	list_for_each_entry(xfer, &message->transfers,
	177	transfer_list) {
	178	if (xfer->rx_buf)
	179	m_cmd = AMD_SPI_XFER_RX;
	180	if (xfer->tx_buf)
	181	m_cmd = AMD_SPI_XFER_TX;
	182
	183	if (m_cmd & AMD_SPI_XFER_TX) {
	184	buf = (u8 *)xfer->tx_buf;
	185	tx_len = xfer->len - 1;
	186	cmd_opcode = (u8 )xfer->tx_buf;
	187	buf++;
	188	amd_spi_set_opcode(master, cmd_opcode);
	189
	190	/* Write data into the FIFO. */
	191	for (i = 0; i < tx_len; i++) {
	192	iowrite8(buf[i],
	193	((u8 __iomem *)amd_spi->io_remap_addr +
	194	AMD_SPI_FIFO_BASE + i));
	195	}
	196
	197	amd_spi_set_tx_count(master, tx_len);
	198	amd_spi_clear_fifo_ptr(master);
	199	/* Execute command */
	200	amd_spi_execute_opcode(master);
	201	}
	202	if (m_cmd & AMD_SPI_XFER_RX) {
	203	/*
	204	* Store no. of bytes to be received from
	205	* FIFO
	206	*/
	207	rx_len = xfer->len;
	208	buf = (u8 *)xfer->rx_buf;
	209	amd_spi_set_rx_count(master, rx_len);
	210	amd_spi_clear_fifo_ptr(master);
	211	/* Execute command */
	212	amd_spi_execute_opcode(master);
	213	/* Read data from FIFO to receive buffer */
	214	for (i = 0; i < rx_len; i++)
	215	buf[i] = amd_spi_readreg8(master,
	216	AMD_SPI_FIFO_BASE +
	217	tx_len + i);
	218	}
	219	}
	220
	221	/* Update statistics */
	222	message->actual_length = tx_len + rx_len + 1;
	223	/* complete the transaction */
	224	message->status = 0;
	225	spi_finalize_current_message(master);
	226
	227	return 0;
	228	}
	229
	230	static int amd_spi_master_transfer(struct spi_master *master,
	231	struct spi_message *msg)
	232	{
	233	struct amd_spi *amd_spi = spi_master_get_devdata(master);
	234	struct spi_device *spi = msg->spi;
235
236	amd_spi->chip_select = spi->chip_select;
237	amd_spi_select_chip(master);
238
239	/*
240	* Extract spi_transfers from the spi message and
241	* program the controller.
242	*/
36c72a58	243	amd_spi_fifo_xfer(amd_spi, master, msg);
bbb336f3 SM	244
	245	return 0;
	246	}
	247
	248	static int amd_spi_probe(struct platform_device *pdev)
	249	{
	250	struct device *dev = &pdev->dev;
	251	struct spi_master *master;
	252	struct amd_spi *amd_spi;
bbb336f3 SM	253	int err = 0;
	254
	255	/* Allocate storage for spi_master and driver private data */
	256	master = spi_alloc_master(dev, sizeof(struct amd_spi));
	257	if (!master) {
	258	dev_err(dev, "Error allocating SPI master\n");
	259	return -ENOMEM;
	260	}
	261
	262	amd_spi = spi_master_get_devdata(master);
2ed6e3ba	263	amd_spi->io_remap_addr = devm_platform_ioremap_resource(pdev, 0);
f84b604d WY	264	if (IS_ERR(amd_spi->io_remap_addr)) {
f84b604d WY	265	err = PTR_ERR(amd_spi->io_remap_addr);
bbb336f3	266	dev_err(dev, "error %d ioremap of SPI registers failed\n", err);
bbb336f3 SM	267	goto err_free_master;
	268	}
	269	dev_dbg(dev, "io_remap_address: %p\n", amd_spi->io_remap_addr);
	270
	271	/* Initialize the spi_master fields */
	272	master->bus_num = 0;
	273	master->num_chipselect = 4;
	274	master->mode_bits = 0;
	275	master->flags = SPI_MASTER_HALF_DUPLEX;
	276	master->setup = amd_spi_master_setup;
	277	master->transfer_one_message = amd_spi_master_transfer;
	278
	279	/* Register the controller with SPI framework */
7b9c94bd	280	err = devm_spi_register_master(dev, master);
bbb336f3 SM	281	if (err) {
bbb336f3 SM	282	dev_err(dev, "error %d registering SPI controller\n", err);
2b60c49f	283	goto err_free_master;
bbb336f3	284	}
bbb336f3 SM	285
	286	return 0;
	287
bbb336f3 SM	288	err_free_master:
	289	spi_master_put(master);
	290
cc17fbec	291	return err;
bbb336f3 SM	292	}
bbb336f3 SM	293
85ed0f63	294	#ifdef CONFIG_ACPI
bbb336f3 SM	295	static const struct acpi_device_id spi_acpi_match[] = {
	296	{ "AMDI0061", 0 },
	297	{},
	298	};
	299	MODULE_DEVICE_TABLE(acpi, spi_acpi_match);
85ed0f63	300	#endif
bbb336f3 SM	301
	302	static struct platform_driver amd_spi_driver = {
	303	.driver = {
	304	.name = "amd_spi",
	305	.acpi_match_table = ACPI_PTR(spi_acpi_match),
	306	},
	307	.probe = amd_spi_probe,
bbb336f3 SM	308	};
	309
	310	module_platform_driver(amd_spi_driver);
	311
	312	MODULE_LICENSE("Dual BSD/GPL");
	313	MODULE_AUTHOR("Sanjay Mehta <sanju.mehta@amd.com>");
	314	MODULE_DESCRIPTION("AMD SPI Master Controller Driver");