Re: [PATCH v2 5/5] ACPI / LPSS: add support of shared clock

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday, April 09, 2013 02:05:47 PM Andy Shevchenko wrote:
> From: "Rafael J. Wysocki" <rjw@sisk.pl>

Well, that should be

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> 
> The DMA controller in Lynxpoint is using the LPSS root clock as a functional
> clock to work properly. Proposed patch adds support of the shared clock. It
> also avoids hardcoding the name of the DMA device in clk-lpt.c and the name of
> the root clock in acpi_lpss.c.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

and accordingly:

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>


> ---
>  drivers/acpi/acpi_lpss.c               | 26 ++++++++++++++++++++++----
>  drivers/clk/x86/clk-lpt.c              | 15 +++++++++++----
>  include/linux/platform_data/clk-lpss.h |  5 +++++
>  3 files changed, 38 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
> index b1c9542..652fd5c 100644
> --- a/drivers/acpi/acpi_lpss.c
> +++ b/drivers/acpi/acpi_lpss.c
> @@ -35,11 +35,16 @@ ACPI_MODULE_NAME("acpi_lpss");
>  
>  struct lpss_device_desc {
>  	bool clk_required;
> -	const char *clk_parent;
> +	const char *clkdev_name;
>  	bool ltr_required;
>  	unsigned int prv_offset;
>  };
>  
> +static struct lpss_device_desc lpss_dma_desc = {
> +	.clk_required = true,
> +	.clkdev_name = "hclk",
> +};
> +
>  struct lpss_private_data {
>  	void __iomem *mmio_base;
>  	resource_size_t mmio_size;
> @@ -49,7 +54,6 @@ struct lpss_private_data {
>  
>  static struct lpss_device_desc lpt_dev_desc = {
>  	.clk_required = true,
> -	.clk_parent = "lpss_clk",
>  	.prv_offset = 0x800,
>  	.ltr_required = true,
>  };
> @@ -60,6 +64,9 @@ static struct lpss_device_desc lpt_sdio_dev_desc = {
>  };
>  
>  static const struct acpi_device_id acpi_lpss_device_ids[] = {
> +	/* Generic LPSS devices */
> +	{ "INTL9C60", (unsigned long)&lpss_dma_desc },
> +
>  	/* Lynxpoint LPSS devices */
>  	{ "INT33C0", (unsigned long)&lpt_dev_desc },
>  	{ "INT33C1", (unsigned long)&lpt_dev_desc },
> @@ -91,16 +98,27 @@ static int register_device_clock(struct acpi_device *adev,
>  				 struct lpss_private_data *pdata)
>  {
>  	const struct lpss_device_desc *dev_desc = pdata->dev_desc;
> +	struct lpss_clk_data *clk_data;
>  
>  	if (!lpss_clk_dev)
>  		lpt_register_clock_device();
>  
> -	if (!dev_desc->clk_parent || !pdata->mmio_base
> +	clk_data = platform_get_drvdata(lpss_clk_dev);
> +	if (!clk_data)
> +		return -ENODEV;
> +
> +	if (dev_desc->clkdev_name) {
> +		clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
> +				    dev_name(&adev->dev));
> +		return 0;
> +	}
> +
> +	if (!pdata->mmio_base
>  	    || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
>  		return -ENODATA;
>  
>  	pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev),
> -				       dev_desc->clk_parent, 0,
> +				       clk_data->name, 0,
>  				       pdata->mmio_base + dev_desc->prv_offset,
>  				       0, 0, NULL);
>  	if (IS_ERR(pdata->clk))
> diff --git a/drivers/clk/x86/clk-lpt.c b/drivers/clk/x86/clk-lpt.c
> index 5cf4f46..e70fae3f 100644
> --- a/drivers/clk/x86/clk-lpt.c
> +++ b/drivers/clk/x86/clk-lpt.c
> @@ -15,22 +15,29 @@
>  #include <linux/clk-provider.h>
>  #include <linux/err.h>
>  #include <linux/module.h>
> +#include <linux/platform_data/clk-lpss.h>
>  #include <linux/platform_device.h>
>  
>  #define PRV_CLOCK_PARAMS 0x800
>  
>  static int lpt_clk_probe(struct platform_device *pdev)
>  {
> +	struct lpss_clk_data *drvdata;
>  	struct clk *clk;
>  
> +	drvdata = devm_kmalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
> +	if (!drvdata)
> +		return -ENOMEM;
> +
>  	/* LPSS free running clock */
> -	clk = clk_register_fixed_rate(&pdev->dev, "lpss_clk", NULL, CLK_IS_ROOT,
> -				      100000000);
> +	drvdata->name = "lpss_clk";
> +	clk = clk_register_fixed_rate(&pdev->dev, drvdata->name, NULL,
> +				      CLK_IS_ROOT, 100000000);
>  	if (IS_ERR(clk))
>  		return PTR_ERR(clk);
>  
> -	/* Shared DMA clock */
> -	clk_register_clkdev(clk, "hclk", "INTL9C60.0.auto");
> +	drvdata->clk = clk;
> +	platform_set_drvdata(pdev, drvdata);
>  	return 0;
>  }
>  
> diff --git a/include/linux/platform_data/clk-lpss.h b/include/linux/platform_data/clk-lpss.h
> index 528e73c..2390199 100644
> --- a/include/linux/platform_data/clk-lpss.h
> +++ b/include/linux/platform_data/clk-lpss.h
> @@ -13,6 +13,11 @@
>  #ifndef __CLK_LPSS_H
>  #define __CLK_LPSS_H
>  
> +struct lpss_clk_data {
> +	const char *name;
> +	struct clk *clk;
> +};
> +
>  extern int lpt_clk_init(void);
>  
>  #endif /* __CLK_LPSS_H */
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.