ACPI / LPSS: register clock device for Lynxpoint DMA properly

The DMA controller in Lynxpoint is enumerated as a regular ACPI device now. To
work properly it is using the LPSS root clock as a functional clock. That's why
we have to register the clock device accordingly to the ACPI ID of the DMA
controller. The acpi_lpss.c module is responsible to do the job.

This patch also removes hardcoded 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 <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

3 files changed, 38 insertions, 8 deletions

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index b1c95422ce74..652fd5ce303c 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 5cf4f4686406..4f45eee9e33b 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_kzalloc(&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 528e73ce46d2..23901992b9dd 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 */