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Subject[PATCH] davinci: MMC: add cpufreq support
Date
Add cpufreq support to MMC driver. The clock divider value has to be
modified according to the controller input frequency.

Signed-off-by: Chaithrika U S <chaithrika@ti.com>
---
This patch applies on top of the following two patches submitted to LKML
http://patchwork.kernel.org/patch/54013/
http://patchwork.kernel.org/patch/50914/
drivers/mmc/host/davinci_mmc.c | 100 +++++++++++++++++++++++++++++++++------
1 files changed, 84 insertions(+), 16 deletions(-)
diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
index fe8f613..b54c779 100644
--- a/drivers/mmc/host/davinci_mmc.c
+++ b/drivers/mmc/host/davinci_mmc.c
@@ -25,6 +25,7 @@
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>
+#include <linux/cpufreq.h>
#include <linux/mmc/host.h>
#include <linux/io.h>
#include <linux/irq.h>
@@ -200,6 +201,9 @@ struct mmc_davinci_host {
u8 version;
/* for ns in one cycle calculation */
unsigned ns_in_one_cycle;
+#ifdef CONFIG_CPU_FREQ
+ struct notifier_block freq_transition;
+#endif
};


@@ -739,27 +743,12 @@ static unsigned int calculate_freq_for_card(struct mmc_davinci_host *host,
return mmc_push_pull_divisor;
}

-static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+static void calculate_clk_divider(struct mmc_host *mmc, struct mmc_ios *ios)
{
unsigned int open_drain_freq = 0, mmc_pclk = 0;
unsigned int mmc_push_pull_freq = 0;
struct mmc_davinci_host *host = mmc_priv(mmc);

- mmc_pclk = host->mmc_input_clk;
- dev_dbg(mmc_dev(host->mmc),
- "clock %dHz busmode %d powermode %d Vdd %04x\n",
- ios->clock, ios->bus_mode, ios->power_mode,
- ios->vdd);
- if (ios->bus_width == MMC_BUS_WIDTH_4) {
- dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
- writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
- host->base + DAVINCI_MMCCTL);
- } else {
- dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
- writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
- host->base + DAVINCI_MMCCTL);
- }
-
if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
u32 temp;

@@ -798,6 +787,29 @@ static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)

udelay(10);
}
+}
+
+static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+ unsigned int mmc_pclk = 0;
+ struct mmc_davinci_host *host = mmc_priv(mmc);
+
+ mmc_pclk = host->mmc_input_clk;
+ dev_dbg(mmc_dev(host->mmc),
+ "clock %dHz busmode %d powermode %d Vdd %04x\n",
+ ios->clock, ios->bus_mode, ios->power_mode,
+ ios->vdd);
+ if (ios->bus_width == MMC_BUS_WIDTH_4) {
+ dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
+ writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
+ host->base + DAVINCI_MMCCTL);
+ } else {
+ dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
+ writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
+ host->base + DAVINCI_MMCCTL);
+ }
+
+ calculate_clk_divider(mmc, ios);

host->bus_mode = ios->bus_mode;
if (ios->power_mode == MMC_POWER_UP) {
@@ -1040,6 +1052,52 @@ static struct mmc_host_ops mmc_davinci_ops = {

/*----------------------------------------------------------------------*/

+#ifdef CONFIG_CPU_FREQ
+static int mmc_davinci_cpufreq_transition(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct mmc_davinci_host *host;
+ unsigned int mmc_pclk;
+ struct mmc_host *mmc;
+ unsigned long flags;
+
+ host = container_of(nb, struct mmc_davinci_host, freq_transition);
+ mmc = host->mmc;
+ mmc_pclk = clk_get_rate(host->clk);
+
+ if (val == CPUFREQ_POSTCHANGE) {
+ spin_lock_irqsave(&mmc->lock, flags);
+ host->mmc_input_clk = mmc_pclk;
+ calculate_clk_divider(mmc, &mmc->ios);
+ spin_unlock_irqrestore(&mmc->lock, flags);
+ }
+
+ return 0;
+}
+
+static inline int mmc_davinci_cpufreq_register(struct mmc_davinci_host *host)
+{
+ host->freq_transition.notifier_call = mmc_davinci_cpufreq_transition;
+
+ return cpufreq_register_notifier(&host->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void mmc_davinci_cpufreq_deregister(struct mmc_davinci_host *host)
+{
+ cpufreq_unregister_notifier(&host->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+#else
+static inline int mmc_davinci_cpufreq_register(struct mmc_davinci_host *host)
+{
+ return 0;
+}
+
+static inline void mmc_davinci_cpufreq_deregister(struct mmc_davinci_host *host)
+{
+}
+#endif
static void __init init_mmcsd_host(struct mmc_davinci_host *host)
{
/* DAT line portion is diabled and in reset state */
@@ -1169,6 +1227,12 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, host);

+ ret = mmc_davinci_cpufreq_register(host);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register cpufreq\n");
+ goto cpu_freq_fail;
+ }
+
ret = mmc_add_host(mmc);
if (ret < 0)
goto out;
@@ -1186,6 +1250,8 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
return 0;

out:
+ mmc_davinci_cpufreq_deregister(host);
+cpu_freq_fail:
if (host) {
davinci_release_dma_channels(host);

@@ -1215,6 +1281,8 @@ static int __exit davinci_mmcsd_remove(struct platform_device *pdev)

platform_set_drvdata(pdev, NULL);
if (host) {
+ mmc_davinci_cpufreq_deregister(host);
+
mmc_remove_host(host->mmc);
free_irq(host->irq, host);

--
1.5.6


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