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ACPI / LPSS: Ignore 10ms delay for Braswell 

LPSS devices in Braswell does not need the default 10ms
d3_delay imposed by PCI specification. Removing this
unnecessary delay significantly reduces the resume time
approximately upto 200ms on this platform.

Signed-off-by: Srinidhi Kasagar <srinidhi.kasagar@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
hifive-unleashed-5.1
Srinidhi Kasagar 2015-08-27 21:30:55 +05:30 committed by Rafael J. Wysocki
parent c13dcf9f2d
commit b00855aecb
1 changed files with 32 additions and 6 deletions
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38
drivers/acpi/acpi_lpss.c
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@ -60,6 +60,7 @@ ACPI_MODULE_NAME("acpi_lpss");
#define LPSS_CLK_DIVIDER BIT(2)
#define LPSS_LTR BIT(3)
#define LPSS_SAVE_CTX BIT(4)
#define LPSS_NO_D3_DELAY BIT(5)
struct lpss_private_data;
@ -156,6 +157,10 @@ static const struct lpss_device_desc byt_pwm_dev_desc = {
.flags = LPSS_SAVE_CTX,
};
static const struct lpss_device_desc bsw_pwm_dev_desc = {
.flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
};
static const struct lpss_device_desc byt_uart_dev_desc = {
.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
.clk_con_id = "baudclk",
@ -163,6 +168,14 @@ static const struct lpss_device_desc byt_uart_dev_desc = {
.setup = lpss_uart_setup,
};
static const struct lpss_device_desc bsw_uart_dev_desc = {
.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
| LPSS_NO_D3_DELAY,
.clk_con_id = "baudclk",
.prv_offset = 0x800,
.setup = lpss_uart_setup,
};
static const struct lpss_device_desc byt_spi_dev_desc = {
.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
.prv_offset = 0x400,
@ -178,8 +191,15 @@ static const struct lpss_device_desc byt_i2c_dev_desc = {
.setup = byt_i2c_setup,
};
static const struct lpss_device_desc bsw_i2c_dev_desc = {
.flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
.prv_offset = 0x800,
.setup = byt_i2c_setup,
};
static struct lpss_device_desc bsw_spi_dev_desc = {
.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
| LPSS_NO_D3_DELAY,
.prv_offset = 0x400,
.setup = lpss_deassert_reset,
};
@ -214,11 +234,12 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = {
{ "INT33FC", },
/* Braswell LPSS devices */
{ "80862288", LPSS_ADDR(byt_pwm_dev_desc) },
{ "8086228A", LPSS_ADDR(byt_uart_dev_desc) },
{ "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
{ "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
{ "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
{ "808622C1", LPSS_ADDR(byt_i2c_dev_desc) },
{ "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
/* Broadwell LPSS devices */
{ "INT3430", LPSS_ADDR(lpt_dev_desc) },
{ "INT3431", LPSS_ADDR(lpt_dev_desc) },
{ "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
@ -558,9 +579,14 @@ static void acpi_lpss_restore_ctx(struct device *dev,
* 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.
* transition. However some platforms like BSW does not need this delay.
*/
msleep(10);
unsigned int delay = 10; /* default 10ms delay */
if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
delay = 0;
msleep(delay);
for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
unsigned long offset = i * sizeof(u32);