Unverified Commit 3c651973 authored by Xu Yilun's avatar Xu Yilun Committed by Mark Brown
Browse files

spi: altera: use regmap-mmio instead of direct mmio register access 



This patch adds support for regmap. It makes preparation for supporting
different ways to access the registers.

Signed-off-by: default avatarMatthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: default avatarWu Hao <hao.wu@intel.com>
Signed-off-by: default avatarXu Yilun <yilun.xu@intel.com>
Signed-off-by: default avatarRuss Weight <russell.h.weight@intel.com>
Reviewed-by: default avatarTom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/1592531021-11412-2-git-send-email-yilun.xu@intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 539afdf9

drivers/spi/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ comment "SPI Master Controller Drivers" 


config SPI_ALTERA

	tristate "Altera SPI Controller"

	select REGMAP_MMIO

	help

	  This is the driver for the Altera SPI Controller.

drivers/spi/spi-altera.c

+72 −19
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ 
#define ALTERA_SPI_MAX_CS		32



struct altera_spi {

	void __iomem *base;

	int irq;

	int len;

	int count;
@@ -54,8 +53,43 @@ struct altera_spi { 
	/* data buffers */

	const unsigned char *tx;

	unsigned char *rx;



	struct regmap *regmap;

	struct device *dev;

};



static const struct regmap_config spi_altera_config = {

	.reg_bits = 32,

	.reg_stride = 4,

	.val_bits = 32,

	.fast_io = true,

};



static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,

			   unsigned int val)

{

	int ret;



	ret = regmap_write(hw->regmap, reg, val);

	if (ret)

		dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",

			reg, val, ret);



	return ret;

}



static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,

			  unsigned int *val)

{

	int ret;



	ret = regmap_read(hw->regmap, reg, val);

	if (ret)

		dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);



	return ret;

}



static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)

{

	return spi_master_get_devdata(sdev->master);
@@ -67,12 +101,13 @@ static void altera_spi_set_cs(struct spi_device *spi, bool is_high) 


	if (is_high) {

		hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;

		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

		writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);

		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);

		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL, 0);

	} else {

		writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL);

		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL,

				BIT(spi->chip_select));

		hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;

		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);

	}

}
@@ -99,14 +134,14 @@ static void altera_spi_tx_word(struct altera_spi *hw) 
		}

	}



	writel(txd, hw->base + ALTERA_SPI_TXDATA);

	altr_spi_writel(hw, ALTERA_SPI_TXDATA, txd);

}



static void altera_spi_rx_word(struct altera_spi *hw)

{

	unsigned int rxd;



	rxd = readl(hw->base + ALTERA_SPI_RXDATA);

	altr_spi_readl(hw, ALTERA_SPI_RXDATA, &rxd);

	if (hw->rx) {

		switch (hw->bytes_per_word) {

		case 1:
@@ -133,6 +168,7 @@ static int altera_spi_txrx(struct spi_master *master, 
	struct spi_device *spi, struct spi_transfer *t)

{

	struct altera_spi *hw = spi_master_get_devdata(master);

	u32 val;



	hw->tx = t->tx_buf;

	hw->rx = t->rx_buf;
@@ -143,7 +179,7 @@ static int altera_spi_txrx(struct spi_master *master, 
	if (hw->irq >= 0) {

		/* enable receive interrupt */

		hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;

		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);



		/* send the first byte */

		altera_spi_tx_word(hw);
@@ -151,9 +187,13 @@ static int altera_spi_txrx(struct spi_master *master, 
		while (hw->count < hw->len) {

			altera_spi_tx_word(hw);



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

				 ALTERA_SPI_STATUS_RRDY_MSK))

			for (;;) {

				altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);

				if (val & ALTERA_SPI_STATUS_RRDY_MSK)

					break;



				cpu_relax();

			}



			altera_spi_rx_word(hw);

		}
@@ -175,7 +215,7 @@ static irqreturn_t altera_spi_irq(int irq, void *dev) 
	} else {

		/* disable receive interrupt */

		hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;

		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);



		spi_finalize_current_transfer(master);

	}
@@ -188,7 +228,9 @@ static int altera_spi_probe(struct platform_device *pdev) 
	struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);

	struct altera_spi *hw;

	struct spi_master *master;

	void __iomem *res;

	int err = -ENODEV;

	u32 val;

	u16 i;



	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
@@ -220,19 +262,30 @@ static int altera_spi_probe(struct platform_device *pdev) 
	master->set_cs = altera_spi_set_cs;



	hw = spi_master_get_devdata(master);

	hw->dev = &pdev->dev;



	/* find and map our resources */

	hw->base = devm_platform_ioremap_resource(pdev, 0);

	if (IS_ERR(hw->base)) {

		err = PTR_ERR(hw->base);

	res = devm_platform_ioremap_resource(pdev, 0);

	if (IS_ERR(res)) {

		err = PTR_ERR(res);

		goto exit;

	}



	hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,

					   &spi_altera_config);

	if (IS_ERR(hw->regmap)) {

		dev_err(&pdev->dev, "regmap mmio init failed\n");

		err = PTR_ERR(hw->regmap);

		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 */

	altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);

	altr_spi_writel(hw, ALTERA_SPI_STATUS, 0);	/* clear status reg */

	altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);

	if (val & ALTERA_SPI_STATUS_RRDY_MSK)

		altr_spi_readl(hw, ALTERA_SPI_RXDATA, &val); /* flush rxdata */

	/* irq is optional */

	hw->irq = platform_get_irq(pdev, 0);

	if (hw->irq >= 0) {
@@ -255,7 +308,7 @@ static int altera_spi_probe(struct platform_device *pdev) 
		}

	}



	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);

	dev_info(&pdev->dev, "base %p, irq %d\n", res, hw->irq);



	return 0;

exit:

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