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path: root/drivers/acpi/acpi_lpss.c
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Diffstat (limited to 'drivers/acpi/acpi_lpss.c')
-rw-r--r--drivers/acpi/acpi_lpss.c82
1 files changed, 81 insertions, 1 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 6745fe137b9..69e29f409d4 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -33,6 +33,13 @@ ACPI_MODULE_NAME("acpi_lpss");
#define LPSS_GENERAL_UART_RTS_OVRD BIT(3)
#define LPSS_SW_LTR 0x10
#define LPSS_AUTO_LTR 0x14
+#define LPSS_LTR_SNOOP_REQ BIT(15)
+#define LPSS_LTR_SNOOP_MASK 0x0000FFFF
+#define LPSS_LTR_SNOOP_LAT_1US 0x800
+#define LPSS_LTR_SNOOP_LAT_32US 0xC00
+#define LPSS_LTR_SNOOP_LAT_SHIFT 5
+#define LPSS_LTR_SNOOP_LAT_CUTOFF 3000
+#define LPSS_LTR_MAX_VAL 0x3FF
#define LPSS_TX_INT 0x20
#define LPSS_TX_INT_MASK BIT(1)
@@ -102,6 +109,16 @@ static struct lpss_device_desc lpt_sdio_dev_desc = {
.ltr_required = true,
};
+static struct lpss_shared_clock pwm_clock = {
+ .name = "pwm_clk",
+ .rate = 25000000,
+};
+
+static struct lpss_device_desc byt_pwm_dev_desc = {
+ .clk_required = true,
+ .shared_clock = &pwm_clock,
+};
+
static struct lpss_shared_clock uart_clock = {
.name = "uart_clk",
.rate = 44236800,
@@ -157,6 +174,7 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = {
{ "INT33C7", },
/* BayTrail LPSS devices */
+ { "80860F09", (unsigned long)&byt_pwm_dev_desc },
{ "80860F0A", (unsigned long)&byt_uart_dev_desc },
{ "80860F0E", (unsigned long)&byt_spi_dev_desc },
{ "80860F14", (unsigned long)&byt_sdio_dev_desc },
@@ -315,6 +333,17 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
return ret;
}
+static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
+{
+ return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
+}
+
+static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
+ unsigned int reg)
+{
+ writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
+}
+
static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
{
struct acpi_device *adev;
@@ -336,7 +365,7 @@ static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
ret = -ENODEV;
goto out;
}
- *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
+ *val = __lpss_reg_read(pdata, reg);
out:
spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -389,6 +418,37 @@ static struct attribute_group lpss_attr_group = {
.name = "lpss_ltr",
};
+static void acpi_lpss_set_ltr(struct device *dev, s32 val)
+{
+ struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+ u32 ltr_mode, ltr_val;
+
+ ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
+ if (val < 0) {
+ if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
+ ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
+ __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
+ }
+ return;
+ }
+ ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
+ if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
+ ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
+ val = LPSS_LTR_MAX_VAL;
+ } else if (val > LPSS_LTR_MAX_VAL) {
+ ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
+ val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
+ } else {
+ ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
+ }
+ ltr_val |= val;
+ __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
+ if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
+ ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
+ __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
+ }
+}
+
static int acpi_lpss_platform_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
@@ -426,9 +486,29 @@ static struct notifier_block acpi_lpss_nb = {
.notifier_call = acpi_lpss_platform_notify,
};
+static void acpi_lpss_bind(struct device *dev)
+{
+ struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+ if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
+ return;
+
+ if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
+ dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
+ else
+ dev_err(dev, "MMIO size insufficient to access LTR\n");
+}
+
+static void acpi_lpss_unbind(struct device *dev)
+{
+ dev->power.set_latency_tolerance = NULL;
+}
+
static struct acpi_scan_handler lpss_handler = {
.ids = acpi_lpss_device_ids,
.attach = acpi_lpss_create_device,
+ .bind = acpi_lpss_bind,
+ .unbind = acpi_lpss_unbind,
};
void __init acpi_lpss_init(void)