Commit 0b599603 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Sascha Hauer
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spi/imx: add support for imx51's eCSPI and CSPI 



i.MX51 comes with two eCSPI interfaces (that are quite different from
what was known before---the tried and tested Freescale way) and a CSPI
interface that is identical to the devices found on i.MX25 and i.MX35.

This patch is a merge of two very similar patches (by Jason Wang and Sascha
Hauer resp.) plus a (now hopefully correct) reimplementation of the
clock calculation.

Acked-by: default avatarJason Wang <jason77.wang@gmail.com>
Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
parent 3b2aa89e

drivers/spi/Kconfig

+4 −1
Original line number Diff line number Diff line
@@ -153,7 +153,10 @@ config SPI_IMX_VER_0_4 
	def_bool y if ARCH_MX31



config SPI_IMX_VER_0_7

	def_bool y if ARCH_MX25 || ARCH_MX35

	def_bool y if ARCH_MX25 || ARCH_MX35 || ARCH_MX51



config SPI_IMX_VER_2_3

	def_bool y if ARCH_MX51



config SPI_IMX

	tristate "Freescale i.MX SPI controllers"

drivers/spi/spi_imx.c

+139 −1
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ enum spi_imx_devtype { 
	SPI_IMX_VER_0_4,

	SPI_IMX_VER_0_5,

	SPI_IMX_VER_0_7,

	SPI_IMX_VER_2_3,

	SPI_IMX_VER_AUTODETECT,

};
@@ -155,7 +156,7 @@ static unsigned int spi_imx_clkdiv_1(unsigned int fin, 
	return max;

}



/* MX1, MX31, MX35 */

/* MX1, MX31, MX35, MX51 CSPI */

static unsigned int spi_imx_clkdiv_2(unsigned int fin,

		unsigned int fspi)

{
@@ -170,6 +171,128 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, 
	return 7;

}



#define SPI_IMX2_3_CTRL		0x08

#define SPI_IMX2_3_CTRL_ENABLE		(1 <<  0)

#define SPI_IMX2_3_CTRL_XCH		(1 <<  2)

#define SPI_IMX2_3_CTRL_MODE(cs)	(1 << ((cs) +  4))

#define SPI_IMX2_3_CTRL_POSTDIV_OFFSET	8

#define SPI_IMX2_3_CTRL_PREDIV_OFFSET	12

#define SPI_IMX2_3_CTRL_CS(cs)		((cs) << 18)

#define SPI_IMX2_3_CTRL_BL_OFFSET	20



#define SPI_IMX2_3_CONFIG	0x0c

#define SPI_IMX2_3_CONFIG_SCLKPHA(cs)	(1 << ((cs) +  0))

#define SPI_IMX2_3_CONFIG_SCLKPOL(cs)	(1 << ((cs) +  4))

#define SPI_IMX2_3_CONFIG_SBBCTRL(cs)	(1 << ((cs) +  8))

#define SPI_IMX2_3_CONFIG_SSBPOL(cs)	(1 << ((cs) + 12))



#define SPI_IMX2_3_INT		0x10

#define SPI_IMX2_3_INT_TEEN		(1 <<  0)

#define SPI_IMX2_3_INT_RREN		(1 <<  3)



#define SPI_IMX2_3_STAT		0x18

#define SPI_IMX2_3_STAT_RR		(1 <<  3)



/* MX51 eCSPI */

static unsigned int spi_imx2_3_clkdiv(unsigned int fin, unsigned int fspi)

{

	/*

	 * there are two 4-bit dividers, the pre-divider divides by

	 * $pre, the post-divider by 2^$post

	 */

	unsigned int pre, post;



	if (unlikely(fspi > fin))

		return 0;



	post = fls(fin) - fls(fspi);

	if (fin > fspi << post)

		post++;



	/* now we have: (fin <= fspi << post) with post being minimal */



	post = max(4U, post) - 4;

	if (unlikely(post > 0xf)) {

		pr_err("%s: cannot set clock freq: %u (base freq: %u)\n",

				__func__, fspi, fin);

		return 0xff;

	}



	pre = DIV_ROUND_UP(fin, fspi << post) - 1;



	pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",

			__func__, fin, fspi, post, pre);

	return (pre << SPI_IMX2_3_CTRL_PREDIV_OFFSET) |

		(post << SPI_IMX2_3_CTRL_POSTDIV_OFFSET);

}



static void __maybe_unused spi_imx2_3_intctrl(struct spi_imx_data *spi_imx, int enable)

{

	unsigned val = 0;



	if (enable & MXC_INT_TE)

		val |= SPI_IMX2_3_INT_TEEN;



	if (enable & MXC_INT_RR)

		val |= SPI_IMX2_3_INT_RREN;



	writel(val, spi_imx->base + SPI_IMX2_3_INT);

}



static void __maybe_unused spi_imx2_3_trigger(struct spi_imx_data *spi_imx)

{

	u32 reg;



	reg = readl(spi_imx->base + SPI_IMX2_3_CTRL);

	reg |= SPI_IMX2_3_CTRL_XCH;

	writel(reg, spi_imx->base + SPI_IMX2_3_CTRL);

}



static int __maybe_unused spi_imx2_3_config(struct spi_imx_data *spi_imx,

		struct spi_imx_config *config)

{

	u32 ctrl = SPI_IMX2_3_CTRL_ENABLE, cfg = 0;



	/* set master mode */

	ctrl |= SPI_IMX2_3_CTRL_MODE(config->cs);



	/* set clock speed */

	ctrl |= spi_imx2_3_clkdiv(spi_imx->spi_clk, config->speed_hz);



	/* set chip select to use */

	ctrl |= SPI_IMX2_3_CTRL_CS(config->cs);



	ctrl |= (config->bpw - 1) << SPI_IMX2_3_CTRL_BL_OFFSET;



	cfg |= SPI_IMX2_3_CONFIG_SBBCTRL(config->cs);



	if (config->mode & SPI_CPHA)

		cfg |= SPI_IMX2_3_CONFIG_SCLKPHA(config->cs);



	if (config->mode & SPI_CPOL)

		cfg |= SPI_IMX2_3_CONFIG_SCLKPOL(config->cs);



	if (config->mode & SPI_CS_HIGH)

		cfg |= SPI_IMX2_3_CONFIG_SSBPOL(config->cs);



	writel(ctrl, spi_imx->base + SPI_IMX2_3_CTRL);

	writel(cfg, spi_imx->base + SPI_IMX2_3_CONFIG);



	return 0;

}



static int __maybe_unused spi_imx2_3_rx_available(struct spi_imx_data *spi_imx)

{

	return readl(spi_imx->base + SPI_IMX2_3_STAT) & SPI_IMX2_3_STAT_RR;

}



static void __maybe_unused spi_imx2_3_reset(struct spi_imx_data *spi_imx)

{

	/* drain receive buffer */

	while (spi_imx2_3_rx_available(spi_imx))

		readl(spi_imx->base + MXC_CSPIRXDATA);

}



#define MX31_INTREG_TEEN	(1 << 0)

#define MX31_INTREG_RREN	(1 << 3)
@@ -447,6 +570,15 @@ static struct spi_imx_devtype_data spi_imx_devtype_data[] __devinitdata = { 
		.reset = spi_imx0_4_reset,

	},

#endif

#ifdef CONFIG_SPI_IMX_VER_2_3

	[SPI_IMX_VER_2_3] = {

		.intctrl = spi_imx2_3_intctrl,

		.config = spi_imx2_3_config,

		.trigger = spi_imx2_3_trigger,

		.rx_available = spi_imx2_3_rx_available,

		.reset = spi_imx2_3_reset,

	},

#endif

};



static void spi_imx_chipselect(struct spi_device *spi, int is_active)
@@ -602,6 +734,12 @@ static struct platform_device_id spi_imx_devtype[] = { 
	}, {

		.name = "imx35-cspi",

		.driver_data = SPI_IMX_VER_0_7,

	}, {

		.name = "imx51-cspi",

		.driver_data = SPI_IMX_VER_0_7,

	}, {

		.name = "imx51-ecspi",

		.driver_data = SPI_IMX_VER_2_3,

	}, {

		/* sentinel */

	}

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