[PATCH] davinci: MMC: add cpufreq support

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

[PATCH] davinci: MMC: add cpufreq support

Chaithrika U S
Do you have any review comments or suggestions for this patch?

Regards,
Chaithrika

On Tue, Oct 20, 2009 at 17:40:10, Chaithrika U S wrote:

> 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 <[hidden email]>
> ---
> 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
>