drivers/spi/spi-bcm53xx.c - kernel/msm-4.9 - Gitiles

 #define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/bcma/bcma.h>
 #include <linux/spi/spi.h>

 #include "spi-bcm53xx.h"

 #define BCM53XXSPI_MAX_SPI_BAUD	13500000	/* 216 MHz? */

 /* The longest observed required wait was 19 ms */
 #define BCM53XXSPI_SPE_TIMEOUT_MS	80

 struct bcm53xxspi {
 	struct bcma_device *core;
 	struct spi_master *master;

 	size_t read_offset;
 };

 static inline u32 bcm53xxspi_read(struct bcm53xxspi *b53spi, u16 offset)
 {
 	return bcma_read32(b53spi->core, offset);
 }

 static inline void bcm53xxspi_write(struct bcm53xxspi *b53spi, u16 offset,
 				    u32 value)
 {
 	bcma_write32(b53spi->core, offset, value);
 }

 static inline unsigned int bcm53xxspi_calc_timeout(size_t len)
 {
 	/* Do some magic calculation based on length and buad. Add 10% and 1. */
 	return (len * 9000 / BCM53XXSPI_MAX_SPI_BAUD * 110 / 100) + 1;
 }

 static int bcm53xxspi_wait(struct bcm53xxspi *b53spi, unsigned int timeout_ms)
 {
 	unsigned long deadline;
 	u32 tmp;

 	/* SPE bit has to be 0 before we read MSPI STATUS */
 	deadline = jiffies + BCM53XXSPI_SPE_TIMEOUT_MS * HZ / 1000;
 	do {
 		tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
 		if (!(tmp & B53SPI_MSPI_SPCR2_SPE))
 			break;
 		udelay(5);
 	} while (!time_after_eq(jiffies, deadline));

 	if (tmp & B53SPI_MSPI_SPCR2_SPE)
 		goto spi_timeout;

 	/* Check status */
 	deadline = jiffies + timeout_ms * HZ / 1000;
 	do {
 		tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_MSPI_STATUS);
 		if (tmp & B53SPI_MSPI_MSPI_STATUS_SPIF) {
 			bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0);
 			return 0;
 		}

 		cpu_relax();
 		udelay(100);
 	} while (!time_after_eq(jiffies, deadline));

 spi_timeout:
 	bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0);

 	pr_err("Timeout waiting for SPI to be ready!\n");

 	return -EBUSY;
 }

 static void bcm53xxspi_buf_write(struct bcm53xxspi *b53spi, u8 *w_buf,
 				 size_t len, bool cont)
 {
 	u32 tmp;
 	int i;

 	for (i = 0; i < len; i++) {
 		/* Transmit Register File MSB */
 		bcm53xxspi_write(b53spi, B53SPI_MSPI_TXRAM + 4 * (i * 2),
 				 (unsigned int)w_buf[i]);
 	}

 	for (i = 0; i < len; i++) {
 		tmp = B53SPI_CDRAM_CONT | B53SPI_CDRAM_PCS_DISABLE_ALL |
 		      B53SPI_CDRAM_PCS_DSCK;
 		if (!cont && i == len - 1)
 			tmp &= ~B53SPI_CDRAM_CONT;
 		tmp &= ~0x1;
 		/* Command Register File */
 		bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp);
 	}

 	/* Set queue pointers */
 	bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0);
 	bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP, len - 1);

 	if (cont)
 		bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1);

 	/* Start SPI transfer */
 	tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
 	tmp |= B53SPI_MSPI_SPCR2_SPE;
 	if (cont)
 		tmp |= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD;
 	bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp);

 	/* Wait for SPI to finish */
 	bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len));

 	if (!cont)
 		bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);

 	b53spi->read_offset = len;
 }

 static void bcm53xxspi_buf_read(struct bcm53xxspi *b53spi, u8 *r_buf,
 				size_t len, bool cont)
 {
 	u32 tmp;
 	int i;

 	for (i = 0; i < b53spi->read_offset + len; i++) {
 		tmp = B53SPI_CDRAM_CONT | B53SPI_CDRAM_PCS_DISABLE_ALL |
 		      B53SPI_CDRAM_PCS_DSCK;
 		if (!cont && i == b53spi->read_offset + len - 1)
 			tmp &= ~B53SPI_CDRAM_CONT;
 		tmp &= ~0x1;
 		/* Command Register File */
 		bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp);
 	}

 	/* Set queue pointers */
 	bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0);
 	bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP,
 			 b53spi->read_offset + len - 1);

 	if (cont)
 		bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1);

 	/* Start SPI transfer */
 	tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
 	tmp |= B53SPI_MSPI_SPCR2_SPE;
 	if (cont)
 		tmp |= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD;
 	bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp);

 	/* Wait for SPI to finish */
 	bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len));

 	if (!cont)
 		bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);

 	for (i = 0; i < len; ++i) {
 		int offset = b53spi->read_offset + i;

 		/* Data stored in the transmit register file LSB */
 		r_buf[i] = (u8)bcm53xxspi_read(b53spi, B53SPI_MSPI_RXRAM + 4 * (1 + offset * 2));
 	}

 	b53spi->read_offset = 0;
 }

 static int bcm53xxspi_transfer_one(struct spi_master *master,
 				   struct spi_device *spi,
 				   struct spi_transfer *t)
 {
 	struct bcm53xxspi *b53spi = spi_master_get_devdata(master);
 	u8 *buf;
 	size_t left;

 	if (t->tx_buf) {
 		buf = (u8 *)t->tx_buf;
 		left = t->len;
 		while (left) {
 			size_t to_write = min_t(size_t, 16, left);
 			bool cont = left - to_write > 0;

 			bcm53xxspi_buf_write(b53spi, buf, to_write, cont);
 			left -= to_write;
 			buf += to_write;
 		}
 	}

 	if (t->rx_buf) {
 		buf = (u8 *)t->rx_buf;
 		left = t->len;
 		while (left) {
 			size_t to_read = min_t(size_t, 16 - b53spi->read_offset,
 					       left);
 			bool cont = left - to_read > 0;

 			bcm53xxspi_buf_read(b53spi, buf, to_read, cont);
 			left -= to_read;
 			buf += to_read;
 		}
 	}

 	return 0;
 }

 /**************************************************
  * BCMA
  **************************************************/

 static struct spi_board_info bcm53xx_info = {
 	.modalias	= "bcm53xxspiflash",
 };

 static const struct bcma_device_id bcm53xxspi_bcma_tbl[] = {
 	BCMA_CORE(BCMA_MANUF_BCM, BCMA_CORE_NS_QSPI, BCMA_ANY_REV, BCMA_ANY_CLASS),
 	BCMA_CORETABLE_END
 };
 MODULE_DEVICE_TABLE(bcma, bcm53xxspi_bcma_tbl);

 static int bcm53xxspi_bcma_probe(struct bcma_device *core)
 {
 	struct bcm53xxspi *b53spi;
 	struct spi_master *master;
 	int err;

 	if (core->bus->drv_cc.core->id.rev != 42) {
 		pr_err("SPI on SoC with unsupported ChipCommon rev\n");
 		return -ENOTSUPP;
 	}

 	master = spi_alloc_master(&core->dev, sizeof(*b53spi));
 	if (!master)
 		return -ENOMEM;

 	b53spi = spi_master_get_devdata(master);
 	b53spi->master = master;
 	b53spi->core = core;

 	master->transfer_one = bcm53xxspi_transfer_one;

 	bcma_set_drvdata(core, b53spi);

 	err = devm_spi_register_master(&core->dev, master);
 	if (err) {
 		spi_master_put(master);
 		bcma_set_drvdata(core, NULL);
 		goto out;
 	}

 	/* Broadcom SoCs (at least with the CC rev 42) use SPI for flash only */
 	spi_new_device(master, &bcm53xx_info);

 out:
 	return err;
 }

 static void bcm53xxspi_bcma_remove(struct bcma_device *core)
 {
 	struct bcm53xxspi *b53spi = bcma_get_drvdata(core);

 	spi_unregister_master(b53spi->master);
 }

 static struct bcma_driver bcm53xxspi_bcma_driver = {
 	.name		= KBUILD_MODNAME,
 	.id_table	= bcm53xxspi_bcma_tbl,
 	.probe		= bcm53xxspi_bcma_probe,
 	.remove		= bcm53xxspi_bcma_remove,
 };

 /**************************************************
  * Init & exit
  **************************************************/

 static int __init bcm53xxspi_module_init(void)
 {
 	int err = 0;

 	err = bcma_driver_register(&bcm53xxspi_bcma_driver);
 	if (err)
 		pr_err("Failed to register bcma driver: %d\n", err);

 	return err;
 }

 static void __exit bcm53xxspi_module_exit(void)
 {
 	bcma_driver_unregister(&bcm53xxspi_bcma_driver);
 }

 module_init(bcm53xxspi_module_init);
 module_exit(bcm53xxspi_module_exit);

 MODULE_DESCRIPTION("Broadcom BCM53xx SPI Controller driver");
 MODULE_AUTHOR("Rafał Miłecki <zajec5@gmail.com>");
 MODULE_LICENSE("GPL");
	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include <linux/bcma/bcma.h>
	#include <linux/spi/spi.h>

	#include "spi-bcm53xx.h"

	#define BCM53XXSPI_MAX_SPI_BAUD 13500000 /* 216 MHz? */

	/* The longest observed required wait was 19 ms */
	#define BCM53XXSPI_SPE_TIMEOUT_MS 80

	struct bcm53xxspi {
	struct bcma_device *core;
	struct spi_master *master;

	size_t read_offset;
	};

	static inline u32 bcm53xxspi_read(struct bcm53xxspi *b53spi, u16 offset)
	{
	return bcma_read32(b53spi->core, offset);
	}

	static inline void bcm53xxspi_write(struct bcm53xxspi *b53spi, u16 offset,
	u32 value)
	{
	bcma_write32(b53spi->core, offset, value);
	}

	static inline unsigned int bcm53xxspi_calc_timeout(size_t len)
	{
	/* Do some magic calculation based on length and buad. Add 10% and 1. */
	return (len * 9000 / BCM53XXSPI_MAX_SPI_BAUD * 110 / 100) + 1;
	}

	static int bcm53xxspi_wait(struct bcm53xxspi *b53spi, unsigned int timeout_ms)
	{
	unsigned long deadline;
	u32 tmp;

	/* SPE bit has to be 0 before we read MSPI STATUS */
	deadline = jiffies + BCM53XXSPI_SPE_TIMEOUT_MS * HZ / 1000;
	do {
	tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
	if (!(tmp & B53SPI_MSPI_SPCR2_SPE))
	break;
	udelay(5);
	} while (!time_after_eq(jiffies, deadline));

	if (tmp & B53SPI_MSPI_SPCR2_SPE)
	goto spi_timeout;

	/* Check status */
	deadline = jiffies + timeout_ms * HZ / 1000;
	do {
	tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_MSPI_STATUS);
	if (tmp & B53SPI_MSPI_MSPI_STATUS_SPIF) {
	bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0);
	return 0;
	}

	cpu_relax();
	udelay(100);
	} while (!time_after_eq(jiffies, deadline));

	spi_timeout:
	bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0);

	pr_err("Timeout waiting for SPI to be ready!\n");

	return -EBUSY;
	}

	static void bcm53xxspi_buf_write(struct bcm53xxspi b53spi, u8 w_buf,
	size_t len, bool cont)
	{
	u32 tmp;
	int i;

	for (i = 0; i < len; i++) {
	/* Transmit Register File MSB */
	bcm53xxspi_write(b53spi, B53SPI_MSPI_TXRAM + 4 * (i * 2),
	(unsigned int)w_buf[i]);
	}

	for (i = 0; i < len; i++) {
	tmp = B53SPI_CDRAM_CONT \| B53SPI_CDRAM_PCS_DISABLE_ALL \|
	B53SPI_CDRAM_PCS_DSCK;
	if (!cont && i == len - 1)
	tmp &= ~B53SPI_CDRAM_CONT;
	tmp &= ~0x1;
	/* Command Register File */
	bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp);
	}

	/* Set queue pointers */
	bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0);
	bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP, len - 1);

	if (cont)
	bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1);

	/* Start SPI transfer */
	tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
	tmp \|= B53SPI_MSPI_SPCR2_SPE;
	if (cont)
	tmp \|= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD;
	bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp);

	/* Wait for SPI to finish */
	bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len));

	if (!cont)
	bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);

	b53spi->read_offset = len;
	}

	static void bcm53xxspi_buf_read(struct bcm53xxspi b53spi, u8 r_buf,
	size_t len, bool cont)
	{
	u32 tmp;
	int i;

	for (i = 0; i < b53spi->read_offset + len; i++) {
	tmp = B53SPI_CDRAM_CONT \| B53SPI_CDRAM_PCS_DISABLE_ALL \|
	B53SPI_CDRAM_PCS_DSCK;
	if (!cont && i == b53spi->read_offset + len - 1)
	tmp &= ~B53SPI_CDRAM_CONT;
	tmp &= ~0x1;
	/* Command Register File */
	bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp);
	}

	/* Set queue pointers */
	bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0);
	bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP,
	b53spi->read_offset + len - 1);

	if (cont)
	bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1);

	/* Start SPI transfer */
	tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
	tmp \|= B53SPI_MSPI_SPCR2_SPE;
	if (cont)
	tmp \|= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD;
	bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp);

	/* Wait for SPI to finish */
	bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len));

	if (!cont)
	bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);

	for (i = 0; i < len; ++i) {
	int offset = b53spi->read_offset + i;

	/* Data stored in the transmit register file LSB */
	r_buf[i] = (u8)bcm53xxspi_read(b53spi, B53SPI_MSPI_RXRAM + 4 * (1 + offset * 2));
	}

	b53spi->read_offset = 0;
	}

	static int bcm53xxspi_transfer_one(struct spi_master *master,
	struct spi_device *spi,
	struct spi_transfer *t)
	{
	struct bcm53xxspi *b53spi = spi_master_get_devdata(master);
	u8 *buf;
	size_t left;

	if (t->tx_buf) {
	buf = (u8 *)t->tx_buf;
	left = t->len;
	while (left) {
	size_t to_write = min_t(size_t, 16, left);
	bool cont = left - to_write > 0;

	bcm53xxspi_buf_write(b53spi, buf, to_write, cont);
	left -= to_write;
	buf += to_write;
	}
	}

	if (t->rx_buf) {
	buf = (u8 *)t->rx_buf;
	left = t->len;
	while (left) {
	size_t to_read = min_t(size_t, 16 - b53spi->read_offset,
	left);
	bool cont = left - to_read > 0;

	bcm53xxspi_buf_read(b53spi, buf, to_read, cont);
	left -= to_read;
	buf += to_read;
	}
	}

	return 0;
	}

	/**************************************************
	* BCMA
	**************************************************/

	static struct spi_board_info bcm53xx_info = {
	.modalias = "bcm53xxspiflash",
	};

	static const struct bcma_device_id bcm53xxspi_bcma_tbl[] = {
	BCMA_CORE(BCMA_MANUF_BCM, BCMA_CORE_NS_QSPI, BCMA_ANY_REV, BCMA_ANY_CLASS),
	BCMA_CORETABLE_END
	};
	MODULE_DEVICE_TABLE(bcma, bcm53xxspi_bcma_tbl);

	static int bcm53xxspi_bcma_probe(struct bcma_device *core)
	{
	struct bcm53xxspi *b53spi;
	struct spi_master *master;
	int err;

	if (core->bus->drv_cc.core->id.rev != 42) {
	pr_err("SPI on SoC with unsupported ChipCommon rev\n");
	return -ENOTSUPP;
	}

	master = spi_alloc_master(&core->dev, sizeof(*b53spi));
	if (!master)
	return -ENOMEM;

	b53spi = spi_master_get_devdata(master);
	b53spi->master = master;
	b53spi->core = core;

	master->transfer_one = bcm53xxspi_transfer_one;

	bcma_set_drvdata(core, b53spi);

	err = devm_spi_register_master(&core->dev, master);
	if (err) {
	spi_master_put(master);
	bcma_set_drvdata(core, NULL);
	goto out;
	}

	/* Broadcom SoCs (at least with the CC rev 42) use SPI for flash only */
	spi_new_device(master, &bcm53xx_info);

	out:
	return err;
	}

	static void bcm53xxspi_bcma_remove(struct bcma_device *core)
	{
	struct bcm53xxspi *b53spi = bcma_get_drvdata(core);

	spi_unregister_master(b53spi->master);
	}

	static struct bcma_driver bcm53xxspi_bcma_driver = {
	.name = KBUILD_MODNAME,
	.id_table = bcm53xxspi_bcma_tbl,
	.probe = bcm53xxspi_bcma_probe,
	.remove = bcm53xxspi_bcma_remove,
	};

	/**************************************************
	* Init & exit
	**************************************************/

	static int __init bcm53xxspi_module_init(void)
	{
	int err = 0;

	err = bcma_driver_register(&bcm53xxspi_bcma_driver);
	if (err)
	pr_err("Failed to register bcma driver: %d\n", err);

	return err;
	}

	static void __exit bcm53xxspi_module_exit(void)
	{
	bcma_driver_unregister(&bcm53xxspi_bcma_driver);
	}

	module_init(bcm53xxspi_module_init);
	module_exit(bcm53xxspi_module_exit);

	MODULE_DESCRIPTION("Broadcom BCM53xx SPI Controller driver");
	MODULE_AUTHOR("Rafał Miłecki <zajec5@gmail.com>");
	MODULE_LICENSE("GPL");