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

From: Andy Shevchenko
Date: Tue Apr 09 2013 - 07:07:45 EST


From: "Rafael J. Wysocki" <rjw@xxxxxxx>

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@xxxxxxx>
---
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 */
--
1.8.2.rc0.22.gb3600c3

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