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mmc: spi: Pull out the SSP clock configuration function 

Pull out the MMC clock configuration function and make it
into SSP clock configuration function, so it can be used by
the SPI driver too.

Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Chris Ball <cjb@laptop.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Marek Vasut 2012-08-03 17:26:10 +02:00 committed by Mark Brown
parent 829c1bf40b
commit 1308239858
4 changed files with 66 additions and 39 deletions
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2
drivers/clk/mxs/Makefile
View File

@ -2,7 +2,7 @@
# Makefile for mxs specific clk
#
obj-y += clk.o clk-pll.o clk-ref.o clk-div.o clk-frac.o
obj-y += clk.o clk-pll.o clk-ref.o clk-div.o clk-frac.o clk-ssp.o
obj-$(CONFIG_SOC_IMX23) += clk-imx23.o
obj-$(CONFIG_SOC_IMX28) += clk-imx28.o

62
drivers/clk/mxs/clk-ssp.c Normal file
View File

@ -0,0 +1,62 @@
/*
* Copyright 2012 DENX Software Engineering, GmbH
*
* Pulled from code:
* Portions copyright (C) 2003 Russell King, PXA MMCI Driver
* Portions copyright (C) 2004-2005 Pierre Ossman, W83L51xD SD/MMC driver
*
* Copyright 2008 Embedded Alley Solutions, Inc.
* Copyright 2009-2011 Freescale Semiconductor, Inc.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/spi/mxs-spi.h>
void mxs_ssp_set_clk_rate(struct mxs_ssp *ssp, unsigned int rate)
{
unsigned int ssp_clk, ssp_sck;
u32 clock_divide, clock_rate;
u32 val;
ssp_clk = clk_get_rate(ssp->clk);
for (clock_divide = 2; clock_divide <= 254; clock_divide += 2) {
clock_rate = DIV_ROUND_UP(ssp_clk, rate * clock_divide);
clock_rate = (clock_rate > 0) ? clock_rate - 1 : 0;
if (clock_rate <= 255)
break;
}
if (clock_divide > 254) {
dev_err(ssp->dev,
"%s: cannot set clock to %d\n", __func__, rate);
return;
}
ssp_sck = ssp_clk / clock_divide / (1 + clock_rate);
val = readl(ssp->base + HW_SSP_TIMING(ssp));
val &= ~(BM_SSP_TIMING_CLOCK_DIVIDE | BM_SSP_TIMING_CLOCK_RATE);
val |= BF_SSP(clock_divide, TIMING_CLOCK_DIVIDE);
val |= BF_SSP(clock_rate, TIMING_CLOCK_RATE);
writel(val, ssp->base + HW_SSP_TIMING(ssp));
ssp->clk_rate = ssp_sck;
dev_dbg(ssp->dev,
"%s: clock_divide %d, clock_rate %d, ssp_clk %d, rate_actual %d, rate_requested %d\n",
__func__, clock_divide, clock_rate, ssp_clk, ssp_sck, rate);
}
EXPORT_SYMBOL_GPL(mxs_ssp_set_clk_rate);

39
drivers/mmc/host/mxs-mmc.c
View File

@ -501,43 +501,6 @@ static void mxs_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
mxs_mmc_start_cmd(host, mrq->cmd);
}
static void mxs_mmc_set_clk_rate(struct mxs_mmc_host *host, unsigned int rate)
{
struct mxs_ssp *ssp = &host->ssp;
unsigned int ssp_clk, ssp_sck;
u32 clock_divide, clock_rate;
u32 val;
ssp_clk = clk_get_rate(ssp->clk);
for (clock_divide = 2; clock_divide <= 254; clock_divide += 2) {
clock_rate = DIV_ROUND_UP(ssp_clk, rate * clock_divide);
clock_rate = (clock_rate > 0) ? clock_rate - 1 : 0;
if (clock_rate <= 255)
break;
}
if (clock_divide > 254) {
dev_err(mmc_dev(host->mmc),
"%s: cannot set clock to %d\n", __func__, rate);
return;
}
ssp_sck = ssp_clk / clock_divide / (1 + clock_rate);
val = readl(ssp->base + HW_SSP_TIMING(ssp));
val &= ~(BM_SSP_TIMING_CLOCK_DIVIDE | BM_SSP_TIMING_CLOCK_RATE);
val |= BF_SSP(clock_divide, TIMING_CLOCK_DIVIDE);
val |= BF_SSP(clock_rate, TIMING_CLOCK_RATE);
writel(val, ssp->base + HW_SSP_TIMING(ssp));
ssp->clk_rate = ssp_sck;
dev_dbg(mmc_dev(host->mmc),
"%s: clock_divide %d, clock_rate %d, ssp_clk %d, rate_actual %d, rate_requested %d\n",
__func__, clock_divide, clock_rate, ssp_clk, ssp_sck, rate);
}
static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct mxs_mmc_host *host = mmc_priv(mmc);
@ -550,7 +513,7 @@ static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
host->bus_width = 0;
if (ios->clock)
mxs_mmc_set_clk_rate(host, ios->clock);
mxs_ssp_set_clk_rate(&host->ssp, ios->clock);
}
static void mxs_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)

2
include/linux/spi/mxs-spi.h
View File

@ -136,4 +136,6 @@ struct mxs_ssp {
enum mxs_ssp_id devid;
};
void mxs_ssp_set_clk_rate(struct mxs_ssp *ssp, unsigned int rate);
#endif /* __LINUX_SPI_MXS_SPI_H__ */