leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

spi: sh-hspi: control spi clock more correctly

Browse Source 
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: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Kuninori Morimoto 2012-03-14 02:48:05 -07:00 committed by Grant Likely
parent ec139b67ad
commit 49e599b859
2 changed files with 70 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

86
drivers/spi/spi-sh-hspi.c
View File

@ -22,6 +22,8 @@
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
* *
*/ */
#include <linux/clk.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/timer.h> #include <linux/timer.h>
@ -50,6 +52,7 @@ struct hspi_priv {
void __iomem *addr; void __iomem *addr;
struct spi_master *master; struct spi_master *master;
struct device *dev; struct device *dev;
struct clk *clk;
}; };
/* /*
@ -162,6 +165,59 @@ static int hspi_unprepare_transfer(struct spi_master *master)
return 0; 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, static int hspi_transfer_one_message(struct spi_master *master,
struct spi_message *msg) struct spi_message *msg)
{ {
@ -173,6 +229,8 @@ static int hspi_transfer_one_message(struct spi_master *master,
ret = 0; ret = 0;
list_for_each_entry(t, &msg->transfers, transfer_list) { list_for_each_entry(t, &msg->transfers, transfer_list) {
hspi_hw_setup(hspi, msg, t);
if (t->tx_buf) { if (t->tx_buf) {
ret = hspi_push(hspi, msg, t); ret = hspi_push(hspi, msg, t);
if (ret < 0) 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 hspi_priv *hspi = spi_master_get_devdata(spi->master);
struct device *dev = hspi->dev; struct device *dev = hspi->dev;
struct sh_hspi_info *info = hspi2info(hspi);
u32 data;
if (8 != spi->bits_per_word) { if (8 != spi->bits_per_word) {
dev_err(dev, "bits_per_word should be 8\n"); dev_err(dev, "bits_per_word should be 8\n");
return -EIO; 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); dev_dbg(dev, "%s setup\n", spi->modalias);
return 0; return 0;
@ -237,6 +279,7 @@ static int __devinit hspi_probe(struct platform_device *pdev)
struct resource *res; struct resource *res;
struct spi_master *master; struct spi_master *master;
struct hspi_priv *hspi; struct hspi_priv *hspi;
struct clk *clk;
int ret; int ret;
/* get base addr */ /* get base addr */
@ -252,12 +295,20 @@ static int __devinit hspi_probe(struct platform_device *pdev)
return -ENOMEM; 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); hspi = spi_master_get_devdata(master);
dev_set_drvdata(&pdev->dev, hspi); dev_set_drvdata(&pdev->dev, hspi);
/* init hspi */ /* init hspi */
hspi->master = master; hspi->master = master;
hspi->dev = &pdev->dev; hspi->dev = &pdev->dev;
hspi->clk = clk;
hspi->addr = devm_ioremap(hspi->dev, hspi->addr = devm_ioremap(hspi->dev,
res->start, resource_size(res)); res->start, resource_size(res));
if (!hspi->addr) { if (!hspi->addr) {
@ -289,6 +340,8 @@ static int __devinit hspi_probe(struct platform_device *pdev)
error2: error2:
devm_iounmap(hspi->dev, hspi->addr); devm_iounmap(hspi->dev, hspi->addr);
error1: error1:
clk_put(clk);
error0:
spi_master_put(master); spi_master_put(master);
return ret; return ret;
@ -300,6 +353,7 @@ static int __devexit hspi_remove(struct platform_device *pdev)
pm_runtime_disable(&pdev->dev); pm_runtime_disable(&pdev->dev);
clk_put(hspi->clk);
spi_unregister_master(hspi->master); spi_unregister_master(hspi->master);
devm_iounmap(hspi->dev, hspi->addr); devm_iounmap(hspi->dev, hspi->addr);

11
include/linux/spi/sh_hspi.h
View File

@ -17,18 +17,7 @@
#ifndef SH_HSPI_H #ifndef SH_HSPI_H
#define 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 { struct sh_hspi_info {
u32 flags;
}; };
#endif #endif