[PATCH v3 12/38] mmc: tegra: Poll for calibration completion

Aapo Vienamo
2018-08-30T15:06:13Z

Implement polling with 10 ms timeout for automatic pad drive strength
calibration.

Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
---
drivers/mmc/host/sdhci-tegra.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 11185e96f3c3..56b637c5b594 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -16,6 +16,7 @@
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/iopoll.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>
@@ -50,6 +51,9 @@
#define SDHCI_AUTO_CAL_START BIT(31)
#define SDHCI_AUTO_CAL_ENABLE BIT(29)

+#define SDHCI_TEGRA_AUTO_CAL_STATUS 0x1ec
+#define SDHCI_TEGRA_AUTO_CAL_ACTIVE BIT(31)
+
#define NVQUIRK_FORCE_SDHCI_SPEC_200 BIT(0)
#define NVQUIRK_ENABLE_BLOCK_GAP_DET BIT(1)
#define NVQUIRK_ENABLE_SDHCI_SPEC_300 BIT(2)
@@ -226,13 +230,21 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)

static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
{
- u32 val;
+ u32 reg;
+ int ret;
+
+ reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+ reg |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
+ sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);

- mdelay(1);
+ usleep_range(1, 2);
+ /* 10 ms timeout */
+ ret = readl_poll_timeout(host->ioaddr + SDHCI_TEGRA_AUTO_CAL_STATUS,
+ reg, !(reg & SDHCI_TEGRA_AUTO_CAL_ACTIVE),
+ 1000, 10000);

- val = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
- val |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
- sdhci_writel(host,val, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+ if (ret)
+ dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
}

static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
--
2.18.0