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Commit 49e599b8 authored by Kuninori Morimoto's avatar Kuninori Morimoto Committed by Grant Likely
Browse files

spi: sh-hspi: control spi clock more correctly 



Current sh-hspi had used platform-specific speed.
This patch remove it, and use spi_transfer specific speed.
It removes unnecessary flags from struct sh_hspi_info,
but struct sh_hspi_info is still exist, since sh-hspi needs
platform info in the future.

Signed-off-by: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent ec139b67

drivers/spi/spi-sh-hspi.c

+70 −16
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ 
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 */



#include <linux/clk.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/timer.h>
@@ -50,6 +52,7 @@ struct hspi_priv { 
	void __iomem *addr;

	struct spi_master *master;

	struct device *dev;

	struct clk *clk;

};



/*
@@ -162,6 +165,59 @@ static int hspi_unprepare_transfer(struct spi_master *master) 
	return 0;

}



static void hspi_hw_setup(struct hspi_priv *hspi,

			  struct spi_message *msg,

			  struct spi_transfer *t)

{

	struct spi_device *spi = msg->spi;

	struct device *dev = hspi->dev;

	u32 target_rate;

	u32 spcr, idiv_clk;

	u32 rate, best_rate, min, tmp;



	target_rate = t ? t->speed_hz : 0;

	if (!target_rate)

		target_rate = spi->max_speed_hz;



	/*

	 * find best IDIV/CLKCx settings

	 */

	min = ~0;

	best_rate = 0;

	spcr = 0;

	for (idiv_clk = 0x00; idiv_clk <= 0x3F; idiv_clk++) {

		rate = clk_get_rate(hspi->clk);



		/* IDIV calculation */

		if (idiv_clk & (1 << 5))

			rate /= 128;

		else

			rate /= 16;



		/* CLKCx calculation */

		rate /= (((idiv_clk & 0x1F) + 1) * 2) ;



		/* save best settings */

		tmp = abs(target_rate - rate);

		if (tmp < min) {

			min = tmp;

			spcr = idiv_clk;

			best_rate = rate;

		}

	}



	if (spi->mode & SPI_CPHA)

		spcr |= 1 << 7;

	if (spi->mode & SPI_CPOL)

		spcr |= 1 << 6;



	dev_dbg(dev, "speed %d/%d\n", target_rate, best_rate);



	hspi_write(hspi, SPCR, spcr);

	hspi_write(hspi, SPSR, 0x0);

	hspi_write(hspi, SPSCR, 0x1);	/* master mode */

}



static int hspi_transfer_one_message(struct spi_master *master,

				     struct spi_message *msg)

{
@@ -173,6 +229,8 @@ static int hspi_transfer_one_message(struct spi_master *master, 


	ret = 0;

	list_for_each_entry(t, &msg->transfers, transfer_list) {

		hspi_hw_setup(hspi, msg, t);



		if (t->tx_buf) {

			ret = hspi_push(hspi, msg, t);

			if (ret < 0)
@@ -197,28 +255,12 @@ static int hspi_setup(struct spi_device *spi) 
{

	struct hspi_priv *hspi = spi_master_get_devdata(spi->master);

	struct device *dev = hspi->dev;

	struct sh_hspi_info *info = hspi2info(hspi);

	u32 data;



	if (8 != spi->bits_per_word) {

		dev_err(dev, "bits_per_word should be 8\n");

		return -EIO;

	}



	/* setup first of all in under pm_runtime */

	data = SH_HSPI_CLK_DIVC(info->flags);



	if (info->flags & SH_HSPI_FBS)

		data |= 1 << 7;

	if (info->flags & SH_HSPI_CLKP_HIGH)

		data |= 1 << 6;

	if (info->flags & SH_HSPI_IDIV_DIV128)

		data |= 1 << 5;



	hspi_write(hspi, SPCR, data);

	hspi_write(hspi, SPSR, 0x0);

	hspi_write(hspi, SPSCR, 0x1);	/* master mode */



	dev_dbg(dev, "%s setup\n", spi->modalias);



	return 0;
@@ -237,6 +279,7 @@ static int __devinit hspi_probe(struct platform_device *pdev) 
	struct resource *res;

	struct spi_master *master;

	struct hspi_priv *hspi;

	struct clk *clk;

	int ret;



	/* get base addr */
@@ -252,12 +295,20 @@ static int __devinit hspi_probe(struct platform_device *pdev) 
		return -ENOMEM;

	}



	clk = clk_get(NULL, "shyway_clk");

	if (!clk) {

		dev_err(&pdev->dev, "shyway_clk is required\n");

		ret = -EINVAL;

		goto error0;

	}



	hspi = spi_master_get_devdata(master);

	dev_set_drvdata(&pdev->dev, hspi);



	/* init hspi */

	hspi->master	= master;

	hspi->dev	= &pdev->dev;

	hspi->clk	= clk;

	hspi->addr	= devm_ioremap(hspi->dev,

				       res->start, resource_size(res));

	if (!hspi->addr) {
@@ -289,6 +340,8 @@ static int __devinit hspi_probe(struct platform_device *pdev) 
 error2:

	devm_iounmap(hspi->dev, hspi->addr);

 error1:

	clk_put(clk);

 error0:

	spi_master_put(master);



	return ret;
@@ -300,6 +353,7 @@ static int __devexit hspi_remove(struct platform_device *pdev) 


	pm_runtime_disable(&pdev->dev);



	clk_put(hspi->clk);

	spi_unregister_master(hspi->master);

	devm_iounmap(hspi->dev, hspi->addr);

include/linux/spi/sh_hspi.h

+0 −11
Original line number Diff line number Diff line
@@ -17,18 +17,7 @@ 
#ifndef SH_HSPI_H

#define SH_HSPI_H



/*

 * flags

 *

 *

 */

#define SH_HSPI_CLK_DIVC(d)		(d & 0xFF)



#define SH_HSPI_FBS		(1 << 8)

#define SH_HSPI_CLKP_HIGH	(1 << 9)	/* default LOW */

#define SH_HSPI_IDIV_DIV128	(1 << 10)	/* default div16 */

struct sh_hspi_info {

	u32	flags;

};



#endif