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mmc: tegra: implement memcomp pad calibration 

The Tegra30+ SDMMC module has memcomp pads that are used to
automatically find and set the correct drive strength settings to
the sdmmc pads. The calibration needs to be manually kicked off
when the card signal voltage is changed, after the card clock is
supplied again.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
[Ulf: Rebased to fix a trivial compile error]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Lucas Stach 2016-02-29 21:56:25 +01:00 committed by Ulf Hansson
parent fac49ce575
commit e5c63d91cd
1 changed files with 44 additions and 3 deletions
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47
drivers/mmc/host/sdhci-tegra.c
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@ -12,6 +12,7 @@
*
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
@ -42,12 +43,17 @@
#define SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300 0x20
#define SDHCI_MISC_CTRL_ENABLE_DDR50 0x200
#define SDHCI_TEGRA_AUTO_CAL_CONFIG 0x1e4
#define SDHCI_AUTO_CAL_START BIT(31)
#define SDHCI_AUTO_CAL_ENABLE BIT(29)
#define NVQUIRK_FORCE_SDHCI_SPEC_200 BIT(0)
#define NVQUIRK_ENABLE_BLOCK_GAP_DET BIT(1)
#define NVQUIRK_ENABLE_SDHCI_SPEC_300 BIT(2)
#define NVQUIRK_ENABLE_SDR50 BIT(3)
#define NVQUIRK_ENABLE_SDR104 BIT(4)
#define NVQUIRK_ENABLE_DDR50 BIT(5)
#define NVQUIRK_HAS_PADCALIB BIT(6)
struct sdhci_tegra_soc_data {
const struct sdhci_pltfm_data *pdata;
@ -58,6 +64,7 @@ struct sdhci_tegra {
const struct sdhci_tegra_soc_data *soc_data;
struct gpio_desc *power_gpio;
bool ddr_signaling;
bool pad_calib_required;
};
static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
@ -165,6 +172,9 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
clk_ctrl |= SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE;
sdhci_writel(host, clk_ctrl, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)
tegra_host->pad_calib_required = true;
tegra_host->ddr_signaling = false;
}
@ -187,6 +197,17 @@ static void tegra_sdhci_set_bus_width(struct sdhci_host *host, int bus_width)
sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
}
static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
{
u32 val;
mdelay(1);
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);
}
static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@ -200,7 +221,12 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
clk_set_rate(pltfm_host->clk, host_clk);
host->max_clk = clk_get_rate(pltfm_host->clk);
return sdhci_set_clock(host, clock);
sdhci_set_clock(host, clock);
if (tegra_host->pad_calib_required) {
tegra_sdhci_pad_autocalib(host);
tegra_host->pad_calib_required = false;
}
}
static void tegra_sdhci_set_uhs_signaling(struct sdhci_host *host,
@ -270,6 +296,16 @@ static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
return mmc_send_tuning(host->mmc, opcode, NULL);
}
static void tegra_sdhci_voltage_switch(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)
tegra_host->pad_calib_required = true;
}
static const struct sdhci_ops tegra_sdhci_ops = {
.get_ro = tegra_sdhci_get_ro,
.read_w = tegra_sdhci_readw,
@ -279,6 +315,7 @@ static const struct sdhci_ops tegra_sdhci_ops = {
.reset = tegra_sdhci_reset,
.platform_execute_tuning = tegra_sdhci_execute_tuning,
.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
.voltage_switch = tegra_sdhci_voltage_switch,
.get_max_clock = tegra_sdhci_get_max_clock,
};
@ -312,7 +349,8 @@ static const struct sdhci_tegra_soc_data soc_data_tegra30 = {
.pdata = &sdhci_tegra30_pdata,
.nvquirks = NVQUIRK_ENABLE_SDHCI_SPEC_300 |
NVQUIRK_ENABLE_SDR50 |
NVQUIRK_ENABLE_SDR104,
NVQUIRK_ENABLE_SDR104 |
NVQUIRK_HAS_PADCALIB,
};
static const struct sdhci_ops tegra114_sdhci_ops = {
@ -325,6 +363,7 @@ static const struct sdhci_ops tegra114_sdhci_ops = {
.reset = tegra_sdhci_reset,
.platform_execute_tuning = tegra_sdhci_execute_tuning,
.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
.voltage_switch = tegra_sdhci_voltage_switch,
.get_max_clock = tegra_sdhci_get_max_clock,
};
@ -347,7 +386,8 @@ static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
.pdata = &sdhci_tegra114_pdata,
.nvquirks = NVQUIRK_ENABLE_SDR50 |
NVQUIRK_ENABLE_DDR50 |
NVQUIRK_ENABLE_SDR104,
NVQUIRK_ENABLE_SDR104 |
NVQUIRK_HAS_PADCALIB,
};
static const struct sdhci_pltfm_data sdhci_tegra210_pdata = {
@ -397,6 +437,7 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
tegra_host = sdhci_pltfm_priv(pltfm_host);
tegra_host->ddr_signaling = false;
tegra_host->pad_calib_required = false;
tegra_host->soc_data = soc_data;
rc = mmc_of_parse(host->mmc);