@@ -523,9 +523,10 @@ config X86_INTEL_QUARK
config X86_INTEL_LPSS
bool "Intel Low Power Subsystem Support"
- depends on ACPI
+ depends on X86 && ACPI
select COMMON_CLK
select PINCTRL
+ select IOSF_MBI
---help---
Select to build support for Intel Low Power Subsystem such as
found on Intel Lynxpoint PCH. Selecting this option enables
@@ -16,6 +16,18 @@
#define MBI_MASK_LO 0x000000FF
#define MBI_ENABLE 0xF0
+/* IOSF SB read/write opcodes */
+#define MBI_MMIO_READ 0x00
+#define MBI_MMIO_WRITE 0x01
+#define MBI_CFG_READ 0x04
+#define MBI_CFG_WRITE 0x05
+#define MBI_CR_READ 0x06
+#define MBI_CR_WRITE 0x07
+#define MBI_REG_READ 0x10
+#define MBI_REG_WRITE 0x11
+#define MBI_ESRAM_READ 0x12
+#define MBI_ESRAM_WRITE 0x13
+
/* Baytrail available units */
#define BT_MBI_UNIT_AUNIT 0x00
#define BT_MBI_UNIT_SMC 0x01
@@ -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)
@@ -628,6 +658,89 @@ 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));
@@ -640,7 +753,17 @@ 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)
@@ -648,6 +771,13 @@ 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;
@@ -754,10 +884,19 @@ 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