diff options
Diffstat (limited to 'drivers/acpi/acpi_lpss.c')
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 153 |
1 files changed, 146 insertions, 7 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index a10c2d665ec2..84d3d90557d1 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -15,6 +15,7 @@ #include <linux/clk-provider.h> #include <linux/err.h> #include <linux/io.h> +#include <linux/mutex.h> #include <linux/platform_device.h> #include <linux/platform_data/clk-lpss.h> #include <linux/pm_runtime.h> @@ -26,6 +27,10 @@ ACPI_MODULE_NAME("acpi_lpss"); #ifdef CONFIG_X86_INTEL_LPSS +#include <asm/cpu_device_id.h> +#include <asm/iosf_mbi.h> +#include <asm/pmc_atom.h> + #define LPSS_ADDR(desc) ((unsigned long)&desc) #define LPSS_CLK_SIZE 0x04 @@ -71,7 +76,7 @@ struct lpss_device_desc { void (*setup)(struct lpss_private_data *pdata); }; -static struct lpss_device_desc lpss_dma_desc = { +static const struct lpss_device_desc lpss_dma_desc = { .flags = LPSS_CLK, }; @@ -84,6 +89,23 @@ struct lpss_private_data { u32 prv_reg_ctx[LPSS_PRV_REG_COUNT]; }; +/* LPSS run time quirks */ +static unsigned int lpss_quirks; + +/* + * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device. + * + * The LPSS DMA controller does not have neither _PS0 nor _PS3 method. Moreover + * it can be powered off automatically whenever the last LPSS device goes down. + * In case of no power any access to the DMA controller will hang the system. + * The behaviour is reproduced on some HP laptops based on Intel BayTrail as + * well as on ASuS T100TA transformer. + * + * This quirk overrides power state of entire LPSS island to keep DMA powered + * on whenever we have at least one other device in use. + */ +#define LPSS_QUIRK_ALWAYS_POWER_ON BIT(0) + /* UART Component Parameter Register */ #define LPSS_UART_CPR 0xF4 #define LPSS_UART_CPR_AFCE BIT(4) @@ -196,13 +218,21 @@ static const struct lpss_device_desc bsw_i2c_dev_desc = { .setup = byt_i2c_setup, }; -static struct lpss_device_desc bsw_spi_dev_desc = { +static const struct lpss_device_desc bsw_spi_dev_desc = { .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, .prv_offset = 0x400, .setup = lpss_deassert_reset, }; +#define ICPU(model) { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, } + +static const struct x86_cpu_id lpss_cpu_ids[] = { + ICPU(0x37), /* Valleyview, Bay Trail */ + ICPU(0x4c), /* Braswell, Cherry Trail */ + {} +}; + #else #define LPSS_ADDR(desc) (0UL) @@ -661,6 +691,89 @@ static int acpi_lpss_resume_early(struct device *dev) } #endif /* CONFIG_PM_SLEEP */ +/* IOSF SB for LPSS island */ +#define LPSS_IOSF_UNIT_LPIOEP 0xA0 +#define LPSS_IOSF_UNIT_LPIO1 0xAB +#define LPSS_IOSF_UNIT_LPIO2 0xAC + +#define LPSS_IOSF_PMCSR 0x84 +#define LPSS_PMCSR_D0 0 +#define LPSS_PMCSR_D3hot 3 +#define LPSS_PMCSR_Dx_MASK GENMASK(1, 0) + +#define LPSS_IOSF_GPIODEF0 0x154 +#define LPSS_GPIODEF0_DMA1_D3 BIT(2) +#define LPSS_GPIODEF0_DMA2_D3 BIT(3) +#define LPSS_GPIODEF0_DMA_D3_MASK GENMASK(3, 2) + +static DEFINE_MUTEX(lpss_iosf_mutex); + +static void lpss_iosf_enter_d3_state(void) +{ + u32 value1 = 0; + u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK; + u32 value2 = LPSS_PMCSR_D3hot; + u32 mask2 = LPSS_PMCSR_Dx_MASK; + /* + * PMC provides an information about actual status of the LPSS devices. + * Here we read the values related to LPSS power island, i.e. LPSS + * devices, excluding both LPSS DMA controllers, along with SCC domain. + */ + u32 func_dis, d3_sts_0, pmc_status, pmc_mask = 0xfe000ffe; + int ret; + + ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis); + if (ret) + return; + + mutex_lock(&lpss_iosf_mutex); + + ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0); + if (ret) + goto exit; + + /* + * Get the status of entire LPSS power island per device basis. + * Shutdown both LPSS DMA controllers if and only if all other devices + * are already in D3hot. + */ + pmc_status = (~(d3_sts_0 | func_dis)) & pmc_mask; + if (pmc_status) + goto exit; + + iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE, + LPSS_IOSF_PMCSR, value2, mask2); + + iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE, + LPSS_IOSF_PMCSR, value2, mask2); + + iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE, + LPSS_IOSF_GPIODEF0, value1, mask1); +exit: + mutex_unlock(&lpss_iosf_mutex); +} + +static void lpss_iosf_exit_d3_state(void) +{ + u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3; + u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK; + u32 value2 = LPSS_PMCSR_D0; + u32 mask2 = LPSS_PMCSR_Dx_MASK; + + mutex_lock(&lpss_iosf_mutex); + + iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE, + LPSS_IOSF_GPIODEF0, value1, mask1); + + iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE, + LPSS_IOSF_PMCSR, value2, mask2); + + iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE, + LPSS_IOSF_PMCSR, value2, mask2); + + mutex_unlock(&lpss_iosf_mutex); +} + static int acpi_lpss_runtime_suspend(struct device *dev) { struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); @@ -673,7 +786,17 @@ static int acpi_lpss_runtime_suspend(struct device *dev) if (pdata->dev_desc->flags & LPSS_SAVE_CTX) acpi_lpss_save_ctx(dev, pdata); - return acpi_dev_runtime_suspend(dev); + ret = acpi_dev_runtime_suspend(dev); + + /* + * This call must be last in the sequence, otherwise PMC will return + * wrong status for devices being about to be powered off. See + * lpss_iosf_enter_d3_state() for further information. + */ + if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available()) + lpss_iosf_enter_d3_state(); + + return ret; } static int acpi_lpss_runtime_resume(struct device *dev) @@ -681,6 +804,13 @@ static int acpi_lpss_runtime_resume(struct device *dev) struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); int ret; + /* + * This call is kept first to be in symmetry with + * acpi_lpss_runtime_suspend() one. + */ + if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available()) + lpss_iosf_exit_d3_state(); + ret = acpi_dev_runtime_resume(dev); if (ret) return ret; @@ -798,10 +928,19 @@ static struct acpi_scan_handler lpss_handler = { void __init acpi_lpss_init(void) { - if (!lpt_clk_init()) { - bus_register_notifier(&platform_bus_type, &acpi_lpss_nb); - acpi_scan_add_handler(&lpss_handler); - } + const struct x86_cpu_id *id; + int ret; + + ret = lpt_clk_init(); + if (ret) + return; + + id = x86_match_cpu(lpss_cpu_ids); + if (id) + lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON; + + bus_register_notifier(&platform_bus_type, &acpi_lpss_nb); + acpi_scan_add_handler(&lpss_handler); } #else |