[RFC PATCH v2 10/11] MIPS: Alchemy: au1xmmc: use clk framework

From: Manuel Lauss
Date: Thu Jul 03 2014 - 09:24:48 EST


Use the clock framework to get the peripheral clock rate to
correctly set the MMC/SD bus clock divider.

Signed-off-by: Manuel Lauss <manuel.lauss@xxxxxxxxx>
---
drivers/mmc/host/au1xmmc.c | 31 +++++++++++++++++++++----------
1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/mmc/host/au1xmmc.c b/drivers/mmc/host/au1xmmc.c
index 1837309..0c0ed16 100644
--- a/drivers/mmc/host/au1xmmc.c
+++ b/drivers/mmc/host/au1xmmc.c
@@ -32,6 +32,7 @@
* (the low to high transition will not occur).
*/

+#include <linux/clk.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
@@ -118,6 +119,7 @@ struct au1xmmc_host {
struct au1xmmc_platform_data *platdata;
struct platform_device *pdev;
struct resource *ioarea;
+ struct clk *clk;
};

/* Status flags used by the host structure */
@@ -596,17 +598,10 @@ static void au1xmmc_cmd_complete(struct au1xmmc_host *host, u32 status)

static void au1xmmc_set_clock(struct au1xmmc_host *host, int rate)
{
- unsigned int pbus = get_au1x00_speed();
- unsigned int divisor;
+ unsigned int pbus = clk_get_rate(host->clk);
+ unsigned int divisor = ((pbus / rate) / 2) - 1;
u32 config;

- /* From databook:
- * divisor = ((((cpuclock / sbus_divisor) / 2) / mmcclock) / 2) - 1
- */
- pbus /= ((AU1X_RDSYS(AU1000_SYS_POWERCTRL) & 0x3) + 2);
- pbus /= 2;
- divisor = ((pbus / rate) / 2) - 1;
-
config = __raw_readl(HOST_CONFIG(host));

config &= ~(SD_CONFIG_DIV);
@@ -1029,6 +1024,16 @@ static int au1xmmc_probe(struct platform_device *pdev)
goto out3;
}

+ host->clk = clk_get(&pdev->dev, ALCHEMY_PERIPH_CLK);
+ if (IS_ERR(host->clk)) {
+ dev_err(&pdev->dev, "cannot find clock\n");
+ goto out_irq;
+ }
+ if (clk_prepare_enable(host->clk)) {
+ dev_err(&pdev->dev, "cannot enable clock\n");
+ goto out_clk;
+ }
+
host->status = HOST_S_IDLE;

/* board-specific carddetect setup, if any */
@@ -1105,7 +1110,10 @@ out5:
if (host->platdata && host->platdata->cd_setup &&
!(mmc->caps & MMC_CAP_NEEDS_POLL))
host->platdata->cd_setup(mmc, 0);
-
+out_clk:
+ clk_disable_unprepare(host->clk);
+ clk_put(host->clk);
+out_irq:
free_irq(host->irq, host);
out3:
iounmap((void *)host->iobase);
@@ -1147,6 +1155,9 @@ static int au1xmmc_remove(struct platform_device *pdev)

au1xmmc_set_power(host, 0);

+ clk_disable_unprepare(host->clk);
+ clk_put(host->clk);
+
free_irq(host->irq, host);
iounmap((void *)host->iobase);
release_resource(host->ioarea);
--
2.0.0

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