Add runtime suspend/resume callbacks to save power
when the bus is not in use.
In runtime suspend
- Turn off the SDMMC host CAR clock.
- Turn off the trimmer/DLL circuit(BG) power supply(VREG).
- Turn off the SDMMC host internal clocks.
Re-enable all the disabled clocks/regulators in runtime resume.
Signed-off-by: Aniruddha Rao <anrao@xxxxxxxxxx>
---
drivers/mmc/host/sdhci-tegra.c | 149 ++++++++++++++++++++++++++++++++++++++---
1 file changed, 140 insertions(+), 9 deletions(-)
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 0a3f9d0..1b4b245 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -23,6 +23,7 @@
#include <linux/mmc/slot-gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/ktime.h>
+#include <linux/pm_runtime.h>
#include "sdhci-pltfm.h"
#include "cqhci.h"
@@ -36,6 +37,7 @@
#define SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE BIT(5)
#define SDHCI_CLOCK_CTRL_PADPIPE_CLKEN_OVERRIDE BIT(3)
#define SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE BIT(2)
+#define SDHCI_CLOCK_CTRL_SDMMC_CLK BIT(0)
#define SDHCI_TEGRA_VENDOR_SYS_SW_CTRL 0x104
#define SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE BIT(31)
@@ -51,6 +53,9 @@
#define SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300 0x20
#define SDHCI_MISC_CTRL_ENABLE_DDR50 0x200
+#define SDHCI_TEGRA_VENDOR_IO_TRIM_CTRL_0 0x1AC
+#define SDHCI_TEGRA_IO_TRIM_CTRL_0_SEL_VREG_MASK 0x4
+
#define SDHCI_TEGRA_VENDOR_DLLCAL_CFG 0x1b0
#define SDHCI_TEGRA_DLLCAL_CALIBRATE BIT(31)
@@ -113,6 +118,9 @@
/* SDMMC CQE Base Address for Tegra Host Ver 4.1 and Higher */
#define SDHCI_TEGRA_CQE_BASE_ADDR 0xF000
+#define SDHCI_TEGRA_FALLBACK_CLK_HZ 400000
+#define SDHCI_TEGRA_RTPM_MSEC_TMOUT 10
+
struct sdhci_tegra_soc_data {
const struct sdhci_pltfm_data *pdata;
u64 dma_mask;
@@ -743,6 +751,24 @@ static void tegra_sdhci_parse_dt(struct sdhci_host *host)
tegra_sdhci_parse_tap_and_trim(host);
}
+static void tegra_sdhci_set_bg_trimmer_supply(struct sdhci_host *host,
+ bool enable)
+{
+ unsigned int misc_ctrl;
+
+ misc_ctrl = sdhci_readl(host, SDHCI_TEGRA_VENDOR_IO_TRIM_CTRL_0);
+ if (enable) {
+ misc_ctrl &= ~(SDHCI_TEGRA_IO_TRIM_CTRL_0_SEL_VREG_MASK);
+ sdhci_writel(host, misc_ctrl, SDHCI_TEGRA_VENDOR_IO_TRIM_CTRL_0);
+ udelay(3);
+ sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+ } else {
+ misc_ctrl |= (SDHCI_TEGRA_IO_TRIM_CTRL_0_SEL_VREG_MASK);
+ sdhci_writel(host, misc_ctrl, SDHCI_TEGRA_VENDOR_IO_TRIM_CTRL_0);
+ udelay(1);
+ }
+}
+
static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -780,6 +806,57 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
}
}
+static int tegra_sdhci_set_host_clock(struct sdhci_host *host, bool enable)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
+ u8 vndr_ctrl;
+ int err;
+
+ if (!enable) {
+ dev_dbg(mmc_dev(host->mmc), "Disabling clk\n");
+
+ /*
+ * Power down BG trimmer supply(VREG).
+ * Ensure SDMMC host internal clocks are
+ * turned off before calling this function.
+ */
+ tegra_sdhci_set_bg_trimmer_supply(host, false);
+
+ /* Update SDMMC host CAR clock status */
+ vndr_ctrl = sdhci_readb(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
+ vndr_ctrl &= ~SDHCI_CLOCK_CTRL_SDMMC_CLK;
+ sdhci_writeb(host, vndr_ctrl, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
+
+ /* Disable SDMMC host CAR clock */
+ clk_disable_unprepare(pltfm_host->clk);
+ } else {
+ dev_dbg(mmc_dev(host->mmc), "Enabling clk\n");
+
+ /* Enable SDMMC host CAR clock */
+ err = clk_prepare_enable(pltfm_host->clk);
+ if (err) {
+ dev_err(mmc_dev(host->mmc),
+ "clk enable failed %d\n", err);
+ return err;
+ }
+
+ /* Reset SDMMC host CAR clock status */
+ vndr_ctrl = sdhci_readb(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
+ vndr_ctrl |= SDHCI_CLOCK_CTRL_SDMMC_CLK;
+ sdhci_writeb(host, vndr_ctrl, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
+
+ /*
+ * Power up BG trimmer supply(VREG).
+ * Ensure SDMMC host internal clocks are
+ * turned off before calling this function.
+ */
+ tegra_sdhci_set_bg_trimmer_supply(host, true);
+ }
+
+ return 0;
+}
+
static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -1622,7 +1699,6 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
goto err_clk_get;
}
- clk_prepare_enable(clk);
pltfm_host->clk = clk;
tegra_host->rst = devm_reset_control_get_exclusive(&pdev->dev,
@@ -1645,16 +1721,29 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
usleep_range(2000, 4000);
+ pm_runtime_enable(&pdev->dev);
+ rc = pm_runtime_get_sync(&pdev->dev);
+ if (rc < 0)
+ goto pm_disable;
+ pm_runtime_set_autosuspend_delay(&pdev->dev,
+ SDHCI_TEGRA_RTPM_MSEC_TMOUT);
+ pm_runtime_use_autosuspend(&pdev->dev);
+
rc = sdhci_tegra_add_host(host);
if (rc)
goto err_add_host;
+ pm_runtime_mark_last_busy(&pdev->dev);
+ pm_runtime_put_autosuspend(&pdev->dev);
+
return 0;
err_add_host:
reset_control_assert(tegra_host->rst);
+ pm_runtime_put_autosuspend(&pdev->dev);
+pm_disable:
+ pm_runtime_disable(&pdev->dev);
err_rst_get:
- clk_disable_unprepare(pltfm_host->clk);
err_clk_get:
err_power_req:
err_parse_dt:
@@ -1679,6 +1768,41 @@ static int sdhci_tegra_remove(struct platform_device *pdev)
return 0;
}
+static int sdhci_tegra_runtime_suspend(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+
+ /* Disable SDMMC internal clock */
+ sdhci_set_clock(host, 0);
+
+ /* Disable SDMMC host CAR clock and BG trimmer supply */
+ return tegra_sdhci_set_host_clock(host, false);
+}
+
+static int sdhci_tegra_runtime_resume(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+ unsigned int clk;
+ int err = 0;
+
+ /* Clock enable should be invoked with a non-zero freq */
+ if (host->clock)
+ clk = host->clock;
+ else if (host->mmc->ios.clock)
+ clk = host->mmc->ios.clock;
+ else
+ clk = SDHCI_TEGRA_FALLBACK_CLK_HZ;
+
+ /* Enable SDMMC host CAR clock and BG trimmer supply */
+ err = tegra_sdhci_set_host_clock(host, true);
+ if (!err) {
+ /* Re-enable SDMMC internal clock */
+ sdhci_set_clock(host, clk);
+ }
+
+ return err;
+}
+
#ifdef CONFIG_PM_SLEEP
static int __maybe_unused sdhci_tegra_suspend(struct device *dev)
{
@@ -1686,6 +1810,12 @@ static int __maybe_unused sdhci_tegra_suspend(struct device *dev)
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
int ret;
+ if (pm_runtime_status_suspended(dev)) {
+ ret = tegra_sdhci_set_host_clock(host, true);
+ if (ret)
+ return ret;
+ }
+
if (host->mmc->caps2 & MMC_CAP2_CQE) {
ret = cqhci_suspend(host->mmc);
if (ret)
@@ -1698,8 +1828,7 @@ static int __maybe_unused sdhci_tegra_suspend(struct device *dev)
return ret;
}
- clk_disable_unprepare(pltfm_host->clk);
- return 0;
+ return tegra_sdhci_set_host_clock(host, false);
}
static int __maybe_unused sdhci_tegra_resume(struct device *dev)
@@ -1708,7 +1837,7 @@ static int __maybe_unused sdhci_tegra_resume(struct device *dev)
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
int ret;
- ret = clk_prepare_enable(pltfm_host->clk);
+ ret = tegra_sdhci_set_host_clock(host, true);
if (ret)
return ret;
@@ -1727,13 +1856,15 @@ static int __maybe_unused sdhci_tegra_resume(struct device *dev)
suspend_host:
sdhci_suspend_host(host);
disable_clk:
- clk_disable_unprepare(pltfm_host->clk);
- return ret;
+ return tegra_sdhci_set_host_clock(host, false);
}
#endif
-static SIMPLE_DEV_PM_OPS(sdhci_tegra_dev_pm_ops, sdhci_tegra_suspend,
- sdhci_tegra_resume);
+const struct dev_pm_ops sdhci_tegra_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(sdhci_tegra_suspend, sdhci_tegra_resume)
+ SET_RUNTIME_PM_OPS(sdhci_tegra_runtime_suspend,
+ sdhci_tegra_runtime_resume, NULL)
+};
static struct platform_driver sdhci_tegra_driver = {
.driver = {
--
2.7.4
