diff options
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 71 |
1 files changed, 70 insertions, 1 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 6745fe137b9e..0a68fc6b5800 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) @@ -315,6 +322,17 @@ 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 +354,7 @@ 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 +407,37 @@ 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 +475,29 @@ 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) |