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

 /*
  * Altera SPI driver
  *
  * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
  *
  * Based on spi_s3c24xx.c, which is:
  * Copyright (c) 2006 Ben Dooks
  * Copyright (c) 2006 Simtec Electronics
  *	Ben Dooks <ben@simtec.co.uk>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
 #include <linux/io.h>
 #include <linux/of.h>

 #define DRV_NAME "spi_altera"

 #define ALTERA_SPI_RXDATA	0
 #define ALTERA_SPI_TXDATA	4
 #define ALTERA_SPI_STATUS	8
 #define ALTERA_SPI_CONTROL	12
 #define ALTERA_SPI_SLAVE_SEL	20

 #define ALTERA_SPI_STATUS_ROE_MSK	0x8
 #define ALTERA_SPI_STATUS_TOE_MSK	0x10
 #define ALTERA_SPI_STATUS_TMT_MSK	0x20
 #define ALTERA_SPI_STATUS_TRDY_MSK	0x40
 #define ALTERA_SPI_STATUS_RRDY_MSK	0x80
 #define ALTERA_SPI_STATUS_E_MSK		0x100

 #define ALTERA_SPI_CONTROL_IROE_MSK	0x8
 #define ALTERA_SPI_CONTROL_ITOE_MSK	0x10
 #define ALTERA_SPI_CONTROL_ITRDY_MSK	0x40
 #define ALTERA_SPI_CONTROL_IRRDY_MSK	0x80
 #define ALTERA_SPI_CONTROL_IE_MSK	0x100
 #define ALTERA_SPI_CONTROL_SSO_MSK	0x400

 struct altera_spi {
 	/* bitbang has to be first */
 	struct spi_bitbang bitbang;
 	struct completion done;

 	void __iomem *base;
 	int irq;
 	int len;
 	int count;
 	int bytes_per_word;
 	unsigned long imr;

 	/* data buffers */
 	const unsigned char *tx;
 	unsigned char *rx;
 };

 static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
 {
 	return spi_master_get_devdata(sdev->master);
 }

 static void altera_spi_chipsel(struct spi_device *spi, int value)
 {
 	struct altera_spi *hw = altera_spi_to_hw(spi);

 	if (spi->mode & SPI_CS_HIGH) {
 		switch (value) {
 		case BITBANG_CS_INACTIVE:
 			writel(1 << spi->chip_select,
 			       hw->base + ALTERA_SPI_SLAVE_SEL);
 			hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
 			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
 			break;

 		case BITBANG_CS_ACTIVE:
 			hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
 			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
 			writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
 			break;
 		}
 	} else {
 		switch (value) {
 		case BITBANG_CS_INACTIVE:
 			hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
 			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
 			break;

 		case BITBANG_CS_ACTIVE:
 			writel(1 << spi->chip_select,
 			       hw->base + ALTERA_SPI_SLAVE_SEL);
 			hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
 			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
 			break;
 		}
 	}
 }

 static inline unsigned int hw_txbyte(struct altera_spi *hw, int count)
 {
 	if (hw->tx) {
 		switch (hw->bytes_per_word) {
 		case 1:
 			return hw->tx[count];
 		case 2:
 			return (hw->tx[count * 2]
 				| (hw->tx[count * 2 + 1] << 8));
 		}
 	}
 	return 0;
 }

 static int altera_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
 {
 	struct altera_spi *hw = altera_spi_to_hw(spi);

 	hw->tx = t->tx_buf;
 	hw->rx = t->rx_buf;
 	hw->count = 0;
 	hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
 	hw->len = t->len / hw->bytes_per_word;

 	if (hw->irq >= 0) {
 		/* enable receive interrupt */
 		hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
 		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

 		/* send the first byte */
 		writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);

 		wait_for_completion(&hw->done);
 		/* disable receive interrupt */
 		hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
 		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
 	} else {
 		while (hw->count < hw->len) {
 			unsigned int rxd;

 			writel(hw_txbyte(hw, hw->count),
 			       hw->base + ALTERA_SPI_TXDATA);

 			while (!(readl(hw->base + ALTERA_SPI_STATUS) &
 				 ALTERA_SPI_STATUS_RRDY_MSK))
 				cpu_relax();

 			rxd = readl(hw->base + ALTERA_SPI_RXDATA);
 			if (hw->rx) {
 				switch (hw->bytes_per_word) {
 				case 1:
 					hw->rx[hw->count] = rxd;
 					break;
 				case 2:
 					hw->rx[hw->count * 2] = rxd;
 					hw->rx[hw->count * 2 + 1] = rxd >> 8;
 					break;
 				}
 			}

 			hw->count++;
 		}
 	}

 	return hw->count * hw->bytes_per_word;
 }

 static irqreturn_t altera_spi_irq(int irq, void *dev)
 {
 	struct altera_spi *hw = dev;
 	unsigned int rxd;

 	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
 	if (hw->rx) {
 		switch (hw->bytes_per_word) {
 		case 1:
 			hw->rx[hw->count] = rxd;
 			break;
 		case 2:
 			hw->rx[hw->count * 2] = rxd;
 			hw->rx[hw->count * 2 + 1] = rxd >> 8;
 			break;
 		}
 	}

 	hw->count++;

 	if (hw->count < hw->len)
 		writel(hw_txbyte(hw, hw->count), hw->base + ALTERA_SPI_TXDATA);
 	else
 		complete(&hw->done);

 	return IRQ_HANDLED;
 }

 static int altera_spi_probe(struct platform_device *pdev)
 {
 	struct altera_spi_platform_data *platp = dev_get_platdata(&pdev->dev);
 	struct altera_spi *hw;
 	struct spi_master *master;
 	struct resource *res;
 	int err = -ENODEV;

 	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
 	if (!master)
 		return err;

 	/* setup the master state. */
 	master->bus_num = pdev->id;
 	master->num_chipselect = 16;
 	master->mode_bits = SPI_CS_HIGH;

 	hw = spi_master_get_devdata(master);
 	platform_set_drvdata(pdev, hw);

 	/* setup the state for the bitbang driver */
 	hw->bitbang.master = spi_master_get(master);
 	if (!hw->bitbang.master)
 		return err;
 	hw->bitbang.chipselect = altera_spi_chipsel;
 	hw->bitbang.txrx_bufs = altera_spi_txrx;

 	/* find and map our resources */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	hw->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(hw->base)) {
 		err = PTR_ERR(hw->base);
 		goto exit;
 	}
 	/* program defaults into the registers */
 	hw->imr = 0;		/* disable spi interrupts */
 	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
 	writel(0, hw->base + ALTERA_SPI_STATUS);	/* clear status reg */
 	if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
 		readl(hw->base + ALTERA_SPI_RXDATA);	/* flush rxdata */
 	/* irq is optional */
 	hw->irq = platform_get_irq(pdev, 0);
 	if (hw->irq >= 0) {
 		init_completion(&hw->done);
 		err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
 				       pdev->name, hw);
 		if (err)
 			goto exit;
 	}
 	/* find platform data */
 	if (!platp)
 		hw->bitbang.master->dev.of_node = pdev->dev.of_node;

 	/* register our spi controller */
 	err = spi_bitbang_start(&hw->bitbang);
 	if (err)
 		goto exit;
 	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);

 	return 0;
 exit:
 	spi_master_put(master);
 	return err;
 }

 static int altera_spi_remove(struct platform_device *dev)
 {
 	struct altera_spi *hw = platform_get_drvdata(dev);
 	struct spi_master *master = hw->bitbang.master;

 	spi_bitbang_stop(&hw->bitbang);
 	spi_master_put(master);
 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id altera_spi_match[] = {
 	{ .compatible = "ALTR,spi-1.0", },
 	{ .compatible = "altr,spi-1.0", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, altera_spi_match);
 #endif /* CONFIG_OF */

 static struct platform_driver altera_spi_driver = {
 	.probe = altera_spi_probe,
 	.remove = altera_spi_remove,
 	.driver = {
 		.name = DRV_NAME,
 		.owner = THIS_MODULE,
 		.pm = NULL,
 		.of_match_table = of_match_ptr(altera_spi_match),
 	},
 };
 module_platform_driver(altera_spi_driver);

 MODULE_DESCRIPTION("Altera SPI driver");
 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:" DRV_NAME);
	/*
	* Altera SPI driver
	*
	* Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
	*
	* Based on spi_s3c24xx.c, which is:
	* Copyright (c) 2006 Ben Dooks
	* Copyright (c) 2006 Simtec Electronics
	* Ben Dooks <ben@simtec.co.uk>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/errno.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/spi/spi.h>
	#include <linux/spi/spi_bitbang.h>
	#include <linux/io.h>
	#include <linux/of.h>

	#define DRV_NAME "spi_altera"

	#define ALTERA_SPI_RXDATA 0
	#define ALTERA_SPI_TXDATA 4
	#define ALTERA_SPI_STATUS 8
	#define ALTERA_SPI_CONTROL 12
	#define ALTERA_SPI_SLAVE_SEL 20

	#define ALTERA_SPI_STATUS_ROE_MSK 0x8
	#define ALTERA_SPI_STATUS_TOE_MSK 0x10
	#define ALTERA_SPI_STATUS_TMT_MSK 0x20
	#define ALTERA_SPI_STATUS_TRDY_MSK 0x40
	#define ALTERA_SPI_STATUS_RRDY_MSK 0x80
	#define ALTERA_SPI_STATUS_E_MSK 0x100

	#define ALTERA_SPI_CONTROL_IROE_MSK 0x8
	#define ALTERA_SPI_CONTROL_ITOE_MSK 0x10
	#define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40
	#define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80
	#define ALTERA_SPI_CONTROL_IE_MSK 0x100
	#define ALTERA_SPI_CONTROL_SSO_MSK 0x400

	struct altera_spi {
	/* bitbang has to be first */
	struct spi_bitbang bitbang;
	struct completion done;

	void __iomem *base;
	int irq;
	int len;
	int count;
	int bytes_per_word;
	unsigned long imr;

	/* data buffers */
	const unsigned char *tx;
	unsigned char *rx;
	};

	static inline struct altera_spi altera_spi_to_hw(struct spi_device sdev)
	{
	return spi_master_get_devdata(sdev->master);
	}

	static void altera_spi_chipsel(struct spi_device *spi, int value)
	{
	struct altera_spi *hw = altera_spi_to_hw(spi);

	if (spi->mode & SPI_CS_HIGH) {
	switch (value) {
	case BITBANG_CS_INACTIVE:
	writel(1 << spi->chip_select,
	hw->base + ALTERA_SPI_SLAVE_SEL);
	hw->imr \|= ALTERA_SPI_CONTROL_SSO_MSK;
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	break;

	case BITBANG_CS_ACTIVE:
	hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
	break;
	}
	} else {
	switch (value) {
	case BITBANG_CS_INACTIVE:
	hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	break;

	case BITBANG_CS_ACTIVE:
	writel(1 << spi->chip_select,
	hw->base + ALTERA_SPI_SLAVE_SEL);
	hw->imr \|= ALTERA_SPI_CONTROL_SSO_MSK;
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	break;
	}
	}
	}

	static inline unsigned int hw_txbyte(struct altera_spi *hw, int count)
	{
	if (hw->tx) {
	switch (hw->bytes_per_word) {
	case 1:
	return hw->tx[count];
	case 2:
	return (hw->tx[count * 2]
	\| (hw->tx[count * 2 + 1] << 8));
	}
	}
	return 0;
	}

	static int altera_spi_txrx(struct spi_device spi, struct spi_transfer t)
	{
	struct altera_spi *hw = altera_spi_to_hw(spi);

	hw->tx = t->tx_buf;
	hw->rx = t->rx_buf;
	hw->count = 0;
	hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
	hw->len = t->len / hw->bytes_per_word;

	if (hw->irq >= 0) {
	/* enable receive interrupt */
	hw->imr \|= ALTERA_SPI_CONTROL_IRRDY_MSK;
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

	/* send the first byte */
	writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);

	wait_for_completion(&hw->done);
	/* disable receive interrupt */
	hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	} else {
	while (hw->count < hw->len) {
	unsigned int rxd;

	writel(hw_txbyte(hw, hw->count),
	hw->base + ALTERA_SPI_TXDATA);

	while (!(readl(hw->base + ALTERA_SPI_STATUS) &
	ALTERA_SPI_STATUS_RRDY_MSK))
	cpu_relax();

	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
	if (hw->rx) {
	switch (hw->bytes_per_word) {
	case 1:
	hw->rx[hw->count] = rxd;
	break;
	case 2:
	hw->rx[hw->count * 2] = rxd;
	hw->rx[hw->count * 2 + 1] = rxd >> 8;
	break;
	}
	}

	hw->count++;
	}
	}

	return hw->count * hw->bytes_per_word;
	}

	static irqreturn_t altera_spi_irq(int irq, void *dev)
	{
	struct altera_spi *hw = dev;
	unsigned int rxd;

	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
	if (hw->rx) {
	switch (hw->bytes_per_word) {
	case 1:
	hw->rx[hw->count] = rxd;
	break;
	case 2:
	hw->rx[hw->count * 2] = rxd;
	hw->rx[hw->count * 2 + 1] = rxd >> 8;
	break;
	}
	}

	hw->count++;

	if (hw->count < hw->len)
	writel(hw_txbyte(hw, hw->count), hw->base + ALTERA_SPI_TXDATA);
	else
	complete(&hw->done);

	return IRQ_HANDLED;
	}

	static int altera_spi_probe(struct platform_device *pdev)
	{
	struct altera_spi_platform_data *platp = dev_get_platdata(&pdev->dev);
	struct altera_spi *hw;
	struct spi_master *master;
	struct resource *res;
	int err = -ENODEV;

	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
	if (!master)
	return err;

	/* setup the master state. */
	master->bus_num = pdev->id;
	master->num_chipselect = 16;
	master->mode_bits = SPI_CS_HIGH;

	hw = spi_master_get_devdata(master);
	platform_set_drvdata(pdev, hw);

	/* setup the state for the bitbang driver */
	hw->bitbang.master = spi_master_get(master);
	if (!hw->bitbang.master)
	return err;
	hw->bitbang.chipselect = altera_spi_chipsel;
	hw->bitbang.txrx_bufs = altera_spi_txrx;

	/* find and map our resources */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	hw->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(hw->base)) {
	err = PTR_ERR(hw->base);
	goto exit;
	}
	/* program defaults into the registers */
	hw->imr = 0; /* disable spi interrupts */
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */
	if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
	readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */
	/* irq is optional */
	hw->irq = platform_get_irq(pdev, 0);
	if (hw->irq >= 0) {
	init_completion(&hw->done);
	err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
	pdev->name, hw);
	if (err)
	goto exit;
	}
	/* find platform data */
	if (!platp)
	hw->bitbang.master->dev.of_node = pdev->dev.of_node;

	/* register our spi controller */
	err = spi_bitbang_start(&hw->bitbang);
	if (err)
	goto exit;
	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);

	return 0;
	exit:
	spi_master_put(master);
	return err;
	}

	static int altera_spi_remove(struct platform_device *dev)
	{
	struct altera_spi *hw = platform_get_drvdata(dev);
	struct spi_master *master = hw->bitbang.master;

	spi_bitbang_stop(&hw->bitbang);
	spi_master_put(master);
	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id altera_spi_match[] = {
	{ .compatible = "ALTR,spi-1.0", },
	{ .compatible = "altr,spi-1.0", },
	{},
	};
	MODULE_DEVICE_TABLE(of, altera_spi_match);
	#endif /* CONFIG_OF */

	static struct platform_driver altera_spi_driver = {
	.probe = altera_spi_probe,
	.remove = altera_spi_remove,
	.driver = {
	.name = DRV_NAME,
	.owner = THIS_MODULE,
	.pm = NULL,
	.of_match_table = of_match_ptr(altera_spi_match),
	},
	};
	module_platform_driver(altera_spi_driver);

	MODULE_DESCRIPTION("Altera SPI driver");
	MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:" DRV_NAME);