Merge branch 'acpi-lpss'

* acpi-lpss:
  ACPI / LPSS: support for fractional divider clock
  ACPI / LPSS: custom power domain for LPSS

1 files changed, 202 insertions, 30 deletions

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 0e9c0d38b85c..db362a96c38e 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -19,6 +19,7 @@
 #include <linux/platform_device.h>
 #include <linux/platform_data/clk-lpss.h>
 #include <linux/pm_runtime.h>
+#include <linux/delay.h>
 
 #include "internal.h"
 
@@ -28,6 +29,7 @@ ACPI_MODULE_NAME("acpi_lpss");
 #define LPSS_LTR_SIZE   0x18
 
 /* Offsets relative to LPSS_PRIVATE_OFFSET */
+#define LPSS_CLK_DIVIDER_DEF_MASK       (BIT(1) | BIT(16))
 #define LPSS_GENERAL                    0x08
 #define LPSS_GENERAL_LTR_MODE_SW        BIT(2)
 #define LPSS_GENERAL_UART_RTS_OVRD      BIT(3)
@@ -43,6 +45,8 @@ ACPI_MODULE_NAME("acpi_lpss");
 #define LPSS_TX_INT                     0x20
 #define LPSS_TX_INT_MASK                BIT(1)
 
+#define LPSS_PRV_REG_COUNT              9
+
 struct lpss_shared_clock {
         const char *name;
         unsigned long rate;
@@ -57,7 +61,9 @@ struct lpss_device_desc {
         bool ltr_required;
         unsigned int prv_offset;
         size_t prv_size_override;
+        bool clk_divider;
         bool clk_gate;
+        bool save_ctx;
         struct lpss_shared_clock *shared_clock;
         void (*setup)(struct lpss_private_data *pdata);
 };
@@ -72,6 +78,7 @@ struct lpss_private_data {
         resource_size_t mmio_size;
         struct clk *clk;
         const struct lpss_device_desc *dev_desc;
+        u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
 };
 
 static void lpss_uart_setup(struct lpss_private_data *pdata)
@@ -92,6 +99,14 @@ static struct lpss_device_desc lpt_dev_desc = {
         .clk_required = true,
         .prv_offset = 0x800,
         .ltr_required = true,
+        .clk_divider = true,
+        .clk_gate = true,
+};
+
+static struct lpss_device_desc lpt_i2c_dev_desc = {
+        .clk_required = true,
+        .prv_offset = 0x800,
+        .ltr_required = true,
         .clk_gate = true,
 };
 
@@ -99,6 +114,7 @@ static struct lpss_device_desc lpt_uart_dev_desc = {
         .clk_required = true,
         .prv_offset = 0x800,
         .ltr_required = true,
+        .clk_divider = true,
         .clk_gate = true,
         .setup = lpss_uart_setup,
 };
@@ -116,32 +132,25 @@ static struct lpss_shared_clock pwm_clock = {
 
 static struct lpss_device_desc byt_pwm_dev_desc = {
         .clk_required = true,
+        .save_ctx = true,
         .shared_clock = &pwm_clock,
 };
 
-static struct lpss_shared_clock uart_clock = {
-        .name = "uart_clk",
-        .rate = 44236800,
-};
-
 static struct lpss_device_desc byt_uart_dev_desc = {
         .clk_required = true,
         .prv_offset = 0x800,
+        .clk_divider = true,
         .clk_gate = true,
-        .shared_clock = &uart_clock,
+        .save_ctx = true,
         .setup = lpss_uart_setup,
 };
 
-static struct lpss_shared_clock spi_clock = {
-        .name = "spi_clk",
-        .rate = 50000000,
-};
-
 static struct lpss_device_desc byt_spi_dev_desc = {
         .clk_required = true,
         .prv_offset = 0x400,
+        .clk_divider = true,
         .clk_gate = true,
-        .shared_clock = &spi_clock,
+        .save_ctx = true,
 };
 
 static struct lpss_device_desc byt_sdio_dev_desc = {
@@ -156,6 +165,7 @@ static struct lpss_shared_clock i2c_clock = {
 static struct lpss_device_desc byt_i2c_dev_desc = {
         .clk_required = true,
         .prv_offset = 0x800,
+        .save_ctx = true,
         .shared_clock = &i2c_clock,
 };
 
@@ -166,8 +176,8 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = {
         /* Lynxpoint LPSS devices */
         { "INT33C0", (unsigned long)&lpt_dev_desc },
         { "INT33C1", (unsigned long)&lpt_dev_desc },
-        { "INT33C2", (unsigned long)&lpt_dev_desc },
-        { "INT33C3", (unsigned long)&lpt_dev_desc },
+        { "INT33C2", (unsigned long)&lpt_i2c_dev_desc },
+        { "INT33C3", (unsigned long)&lpt_i2c_dev_desc },
         { "INT33C4", (unsigned long)&lpt_uart_dev_desc },
         { "INT33C5", (unsigned long)&lpt_uart_dev_desc },
         { "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
@@ -183,8 +193,8 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = {
 
         { "INT3430", (unsigned long)&lpt_dev_desc },
         { "INT3431", (unsigned long)&lpt_dev_desc },
-        { "INT3432", (unsigned long)&lpt_dev_desc },
-        { "INT3433", (unsigned long)&lpt_dev_desc },
+        { "INT3432", (unsigned long)&lpt_i2c_dev_desc },
+        { "INT3433", (unsigned long)&lpt_i2c_dev_desc },
         { "INT3434", (unsigned long)&lpt_uart_dev_desc },
         { "INT3435", (unsigned long)&lpt_uart_dev_desc },
         { "INT3436", (unsigned long)&lpt_sdio_dev_desc },
@@ -212,9 +222,11 @@ static int register_device_clock(struct acpi_device *adev,
 {
         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
         struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
+        const char *devname = dev_name(&adev->dev);
         struct clk *clk = ERR_PTR(-ENODEV);
         struct lpss_clk_data *clk_data;
-        const char *parent;
+        const char *parent, *clk_name;
+        void __iomem *prv_base;
 
         if (!lpss_clk_dev)
                 lpt_register_clock_device();
@@ -225,7 +237,7 @@ static int register_device_clock(struct acpi_device *adev,
 
         if (dev_desc->clkdev_name) {
                 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
-                                    dev_name(&adev->dev));
+                                    devname);
                 return 0;
         }
 
@@ -234,6 +246,7 @@ static int register_device_clock(struct acpi_device *adev,
                 return -ENODATA;
 
         parent = clk_data->name;
+        prv_base = pdata->mmio_base + dev_desc->prv_offset;
 
         if (shared_clock) {
                 clk = shared_clock->clk;
@@ -247,16 +260,41 @@ static int register_device_clock(struct acpi_device *adev,
         }
 
         if (dev_desc->clk_gate) {
-                clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0,
-                                        pdata->mmio_base + dev_desc->prv_offset,
-                                        0, 0, NULL);
-                pdata->clk = clk;
+                clk = clk_register_gate(NULL, devname, parent, 0,
+                                        prv_base, 0, 0, NULL);
+                parent = devname;
+        }
+
+        if (dev_desc->clk_divider) {
+                /* Prevent division by zero */
+                if (!readl(prv_base))
+                        writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
+
+                clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
+                if (!clk_name)
+                        return -ENOMEM;
+                clk = clk_register_fractional_divider(NULL, clk_name, parent,
+                                                      0, prv_base,
+                                                      1, 15, 16, 15, 0, NULL);
+                parent = clk_name;
+
+                clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
+                if (!clk_name) {
+                        kfree(parent);
+                        return -ENOMEM;
+                }
+                clk = clk_register_gate(NULL, clk_name, parent,
+                                        CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
+                                        prv_base, 31, 0, NULL);
+                kfree(parent);
+                kfree(clk_name);
         }
 
         if (IS_ERR(clk))
                 return PTR_ERR(clk);
 
-        clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
+        pdata->clk = clk;
+        clk_register_clkdev(clk, NULL, devname);
         return 0;
 }
 
@@ -454,6 +492,126 @@ static void acpi_lpss_set_ltr(struct device *dev, s32 val)
         }
 }
 
+#ifdef CONFIG_PM
+/**
+ * acpi_lpss_save_ctx() - Save the private registers of LPSS device
+ * @dev: LPSS device
+ *
+ * Most LPSS devices have private registers which may loose their context when
+ * the device is powered down. acpi_lpss_save_ctx() saves those registers into
+ * prv_reg_ctx array.
+ */
+static void acpi_lpss_save_ctx(struct device *dev)
+{
+        struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+        unsigned int i;
+
+        for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
+                unsigned long offset = i * sizeof(u32);
+
+                pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
+                dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
+                        pdata->prv_reg_ctx[i], offset);
+        }
+}
+
+/**
+ * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
+ * @dev: LPSS device
+ *
+ * Restores the registers that were previously stored with acpi_lpss_save_ctx().
+ */
+static void acpi_lpss_restore_ctx(struct device *dev)
+{
+        struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+        unsigned int i;
+
+        /*
+         * The following delay is needed or the subsequent write operations may
+         * fail. The LPSS devices are actually PCI devices and the PCI spec
+         * expects 10ms delay before the device can be accessed after D3 to D0
+         * transition.
+         */
+        msleep(10);
+
+        for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
+                unsigned long offset = i * sizeof(u32);
+
+                __lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
+                dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
+                        pdata->prv_reg_ctx[i], offset);
+        }
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_lpss_suspend_late(struct device *dev)
+{
+        int ret = pm_generic_suspend_late(dev);
+
+        if (ret)
+                return ret;
+
+        acpi_lpss_save_ctx(dev);
+        return acpi_dev_suspend_late(dev);
+}
+
+static int acpi_lpss_restore_early(struct device *dev)
+{
+        int ret = acpi_dev_resume_early(dev);
+
+        if (ret)
+                return ret;
+
+        acpi_lpss_restore_ctx(dev);
+        return pm_generic_resume_early(dev);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM_RUNTIME
+static int acpi_lpss_runtime_suspend(struct device *dev)
+{
+        int ret = pm_generic_runtime_suspend(dev);
+
+        if (ret)
+                return ret;
+
+        acpi_lpss_save_ctx(dev);
+        return acpi_dev_runtime_suspend(dev);
+}
+
+static int acpi_lpss_runtime_resume(struct device *dev)
+{
+        int ret = acpi_dev_runtime_resume(dev);
+
+        if (ret)
+                return ret;
+
+        acpi_lpss_restore_ctx(dev);
+        return pm_generic_runtime_resume(dev);
+}
+#endif /* CONFIG_PM_RUNTIME */
+#endif /* CONFIG_PM */
+
+static struct dev_pm_domain acpi_lpss_pm_domain = {
+        .ops = {
+#ifdef CONFIG_PM_SLEEP
+                .suspend_late = acpi_lpss_suspend_late,
+                .restore_early = acpi_lpss_restore_early,
+                .prepare = acpi_subsys_prepare,
+                .complete = acpi_subsys_complete,
+                .suspend = acpi_subsys_suspend,
+                .resume_early = acpi_subsys_resume_early,
+                .freeze = acpi_subsys_freeze,
+                .poweroff = acpi_subsys_suspend,
+                .poweroff_late = acpi_subsys_suspend_late,
+#endif
+#ifdef CONFIG_PM_RUNTIME
+                .runtime_suspend = acpi_lpss_runtime_suspend,
+                .runtime_resume = acpi_lpss_runtime_resume,
+#endif
+        },
+};
+
 static int acpi_lpss_platform_notify(struct notifier_block *nb,
                                      unsigned long action, void *data)
 {
@@ -461,7 +619,6 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
         struct lpss_private_data *pdata;
         struct acpi_device *adev;
         const struct acpi_device_id *id;
-        int ret = 0;
 
         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
         if (!id || !id->driver_data)
@@ -471,7 +628,7 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
                 return 0;
 
         pdata = acpi_driver_data(adev);
-        if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
+        if (!pdata || !pdata->mmio_base)
                 return 0;
 
         if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
@@ -479,12 +636,27 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
                 return 0;
         }
 
-        if (action == BUS_NOTIFY_ADD_DEVICE)
-                ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
-        else if (action == BUS_NOTIFY_DEL_DEVICE)
-                sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
+        switch (action) {
+        case BUS_NOTIFY_BOUND_DRIVER:
+                if (pdata->dev_desc->save_ctx)
+                        pdev->dev.pm_domain = &acpi_lpss_pm_domain;
+                break;
+        case BUS_NOTIFY_UNBOUND_DRIVER:
+                if (pdata->dev_desc->save_ctx)
+                        pdev->dev.pm_domain = NULL;
+                break;
+        case BUS_NOTIFY_ADD_DEVICE:
+                if (pdata->dev_desc->ltr_required)
+                        return sysfs_create_group(&pdev->dev.kobj,
+                                                  &lpss_attr_group);
+        case BUS_NOTIFY_DEL_DEVICE:
+                if (pdata->dev_desc->ltr_required)
+                        sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
+        default:
+                break;
+        }
 
-        return ret;
+        return 0;
 }
 
 static struct notifier_block acpi_lpss_nb = {