summaryrefslogtreecommitdiffstats
path: root/drivers/mmc
diff options
context:
space:
mode:
authoryangbo lu <yangbo.lu@nxp.com>2017-04-20 16:14:40 +0800
committerUlf Hansson <ulf.hansson@linaro.org>2017-04-24 21:42:25 +0200
commit19c3a0ef65adf090cb592dfe3e575f40322c88d8 (patch)
treebdff42cb2935f67f26222b2d0ee6262ae0d71ed1 /drivers/mmc
parenta72016a44703476bdb3567a13695938566e8f413 (diff)
downloadlinux-stable-19c3a0ef65adf090cb592dfe3e575f40322c88d8.tar.gz
linux-stable-19c3a0ef65adf090cb592dfe3e575f40322c88d8.tar.bz2
linux-stable-19c3a0ef65adf090cb592dfe3e575f40322c88d8.zip
mmc: sdhci-of-esdhc: add peripheral clock support
eSDHC could select peripheral clock or platform clock as clock source by the PCS bit of eSDHC Control Register, and this bit couldn't be reset by software reset for all. In default, the platform clock is used. But we have to use peripheral clock since it has a higher frequency to support eMMC HS200 mode and SD UHS-I mode. This patch is to add peripheral clock support and use it instead of platform clock if it's declared in eSDHC dts node. Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci-esdhc.h1
-rw-r--r--drivers/mmc/host/sdhci-of-esdhc.c73
2 files changed, 72 insertions, 2 deletions
diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index ece8b37e51dd..5343fc062e22 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -54,6 +54,7 @@
/* Control Register for DMA transfer */
#define ESDHC_DMA_SYSCTL 0x40c
+#define ESDHC_PERIPHERAL_CLK_SEL 0x00080000
#define ESDHC_DMA_SNOOP 0x00000040
#endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index ff37e7459386..0b3f05ae8328 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -19,6 +19,8 @@
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/sys_soc.h>
+#include <linux/clk.h>
+#include <linux/ktime.h>
#include <linux/mmc/host.h>
#include "sdhci-pltfm.h"
#include "sdhci-esdhc.h"
@@ -30,6 +32,7 @@ struct sdhci_esdhc {
u8 vendor_ver;
u8 spec_ver;
bool quirk_incorrect_hostver;
+ unsigned int peripheral_clock;
};
/**
@@ -414,15 +417,25 @@ static int esdhc_of_enable_dma(struct sdhci_host *host)
static unsigned int esdhc_of_get_max_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
- return pltfm_host->clock;
+ if (esdhc->peripheral_clock)
+ return esdhc->peripheral_clock;
+ else
+ return pltfm_host->clock;
}
static unsigned int esdhc_of_get_min_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
+ unsigned int clock;
- return pltfm_host->clock / 256 / 16;
+ if (esdhc->peripheral_clock)
+ clock = esdhc->peripheral_clock;
+ else
+ clock = pltfm_host->clock;
+ return clock / 256 / 16;
}
static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
@@ -512,6 +525,33 @@ static void esdhc_pltfm_set_bus_width(struct sdhci_host *host, int width)
sdhci_writel(host, ctrl, ESDHC_PROCTL);
}
+static void esdhc_clock_enable(struct sdhci_host *host, bool enable)
+{
+ u32 val;
+ ktime_t timeout;
+
+ val = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
+
+ if (enable)
+ val |= ESDHC_CLOCK_SDCLKEN;
+ else
+ val &= ~ESDHC_CLOCK_SDCLKEN;
+
+ sdhci_writel(host, val, ESDHC_SYSTEM_CONTROL);
+
+ /* Wait max 20 ms */
+ timeout = ktime_add_ms(ktime_get(), 20);
+ val = ESDHC_CLOCK_STABLE;
+ while (!(sdhci_readl(host, ESDHC_PRSSTAT) & val)) {
+ if (ktime_after(ktime_get(), timeout)) {
+ pr_err("%s: Internal clock never stabilised.\n",
+ mmc_hostname(host->mmc));
+ break;
+ }
+ udelay(10);
+ }
+}
+
static void esdhc_reset(struct sdhci_host *host, u8 mask)
{
sdhci_reset(host, mask);
@@ -613,6 +653,9 @@ static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host;
struct sdhci_esdhc *esdhc;
+ struct device_node *np;
+ struct clk *clk;
+ u32 val;
u16 host_ver;
pltfm_host = sdhci_priv(host);
@@ -626,6 +669,32 @@ static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
esdhc->quirk_incorrect_hostver = true;
else
esdhc->quirk_incorrect_hostver = false;
+
+ np = pdev->dev.of_node;
+ clk = of_clk_get(np, 0);
+ if (!IS_ERR(clk)) {
+ /*
+ * esdhc->peripheral_clock would be assigned with a value
+ * which is eSDHC base clock when use periperal clock.
+ * For ls1046a, the clock value got by common clk API is
+ * peripheral clock while the eSDHC base clock is 1/2
+ * peripheral clock.
+ */
+ if (of_device_is_compatible(np, "fsl,ls1046a-esdhc"))
+ esdhc->peripheral_clock = clk_get_rate(clk) / 2;
+ else
+ esdhc->peripheral_clock = clk_get_rate(clk);
+
+ clk_put(clk);
+ }
+
+ if (esdhc->peripheral_clock) {
+ esdhc_clock_enable(host, false);
+ val = sdhci_readl(host, ESDHC_DMA_SYSCTL);
+ val |= ESDHC_PERIPHERAL_CLK_SEL;
+ sdhci_writel(host, val, ESDHC_DMA_SYSCTL);
+ esdhc_clock_enable(host, true);
+ }
}
static int sdhci_esdhc_probe(struct platform_device *pdev)