On 11/14/11 00:23, Sujit Reddy Thumma wrote:
> diff --git a/Documentation/mmc/mmc-dev-attrs.txt
> b/Documentation/mmc/mmc-dev-attrs.txt
> index 8898a95..b024556 100644
> --- a/Documentation/mmc/mmc-dev-attrs.txt
> +++ b/Documentation/mmc/mmc-dev-attrs.txt
> @@ -64,3 +64,13 @@ Note on Erase Size and Preferred Erase Size:
> size specified by the card.
>
> "preferred_erase_size" is in bytes.
> +
> +SD/MMC/SDIO Clock Gating Attribute
> +==================================
> +
> +Read and write access is provided to following attribute.
> +This attribute appears only if CONFIG_MMC_CLKGATE is enabled.
> +
> + clkgate_delay Tune the clock gating delay with desired value in milli
> seconds.
milliseconds is one word.
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index ca2e4f5..ba4cc5d 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -53,6 +53,31 @@ static DEFINE_IDR(mmc_host_idr);
> static DEFINE_SPINLOCK(mmc_host_lock);
>
> #ifdef CONFIG_MMC_CLKGATE
> +static ssize_t clkgate_delay_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct mmc_host *host = cls_dev_to_mmc_host(dev);
> + return snprintf(buf, PAGE_SIZE, "%lu millisecs\n",
Perhaps this should just be %lu to simplify userspace parsing.
> +static ssize_t clkgate_delay_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count)
> +{
> + struct mmc_host *host = cls_dev_to_mmc_host(dev);
> + unsigned long flags, value;
> +
> + if (kstrtoul(buf, 0, &value))
> + return -EINVAL;
> +
> + spin_lock_irqsave(&host->clk_lock, flags);
> + host->clkgate_delay = value;
> + spin_unlock_irqrestore(&host->clk_lock, flags);
> +
> + pr_info("%s: clock gate delay set to %lu ms\n",
> + mmc_hostname(host), value);
Is this pr_info() necessary?
> @@ -236,6 +269,17 @@ static inline void mmc_host_clk_exit(struct mmc_host
> *host)
> WARN_ON(host->clk_requests > 1);
> }
>
> +static inline void mmc_host_clk_sysfs_init(struct mmc_host *host)
> +{
> + host->clkgate_delay_attr.show = clkgate_delay_show;
> + host->clkgate_delay_attr.store = clkgate_delay_store;
> + sysfs_attr_init(&host->clkgate_delay_attr.attr);
> + host->clkgate_delay_attr.attr.name = "clkgate_delay";
> + host->clkgate_delay_attr.attr.mode = S_IRUGO | S_IWUSR;
> + if (device_create_file(&host->class_dev, &host->clkgate_delay_attr))
> + pr_err("%s: Failed to create clkgate_delay sysfs entry\n",
> + mmc_hostname(host));
> +}
Would it be simpler to assign dev_attrs in the mmc_host_class instead?
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index a3ac9c4..7206c80 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -253,10 +253,12 @@ struct mmc_host {
> int clk_requests; /* internal reference counter */
> unsigned int clk_delay; /* number of MCI clk hold
> cycles */
> bool clk_gated; /* clock gated */
> - struct work_struct clk_gate_work; /* delayed clock gate */
> + struct delayed_work clk_gate_work; /* delayed clock gate */
> unsigned int clk_old; /* old clock value cache */
> spinlock_t clk_lock; /* lock for clk fields */
> struct mutex clk_gate_mutex; /* mutex for clock gating */
> + struct device_attribute clkgate_delay_attr;
If you used the class device attributes then this would probably go away.
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
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