// SPDX-License-Identifier: GPL-2.0-only
/*
* Atmel SDMMC controller driver.
*
* Copyright (C) 2015 Atmel,
* 2015 Ludovic Desroches <ludovic.desroches@atmel.com>
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mmc/host.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include "sdhci-pltfm.h"
#define SDMMC_MC1R 0x204
#define SDMMC_MC1R_DDR BIT(3)
#define SDMMC_MC1R_FCD BIT(7)
#define SDMMC_CACR 0x230
#define SDMMC_CACR_CAPWREN BIT(0)
#define SDMMC_CACR_KEY (0x46 << 8)
#define SDHCI_AT91_PRESET_COMMON_CONF 0x400 /* drv type B, programmable clock mode */
struct sdhci_at91_priv {
struct clk *hclock;
struct clk *gck;
struct clk *mainck;
bool restore_needed;
};
static void sdhci_at91_set_force_card_detect(struct sdhci_host *host)
{
u8 mc1r;
mc1r = readb(host->ioaddr + SDMMC_MC1R);
mc1r |= SDMMC_MC1R_FCD;
writeb(mc1r, host->ioaddr + SDMMC_MC1R);
}
static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
{
u16 clk;
unsigned long timeout;
host->mmc->actual_clock = 0;
/*
* There is no requirement to disable the internal clock before
* changing the SD clock configuration. Moreover, disabling the
* internal clock, changing the configuration and re-enabling the
* internal clock causes some bugs. It can prevent to get the internal
* clock stable flag ready and an unexpected switch to the base clock
* when using presets.
*/
clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
clk &= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
if (clock == 0)
return;
clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
/* Wait max 20 ms */
timeout = 20;
while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
& SDHCI_CLOCK_INT_STABLE)) {
if (timeout == 0) {
pr_err("%s: Internal clock never stabilised.\n",
mmc_hostname(host->mmc));
return;
}
timeout--;
mdelay(1);
}
clk |= SDHCI_CLOCK_CARD_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
}
/*
* In this specific implementation of the SDHCI controller, the power register
* needs to have a valid voltage set even when the power supply is managed by
* an external regulator.
*/
static void sdhci_at91_set_power(struct sdhci_host *host, unsigned char mode,
unsigned short vdd)
{
if (!IS_ERR(host->mmc->supply.vmmc)) {
struct mmc_host *mmc = host->mmc;
mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
}
sdhci_set_power_noreg(host, mode, vdd);
}
static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
unsigned int timing)
{
if (timing == MMC_TIMING_MMC_DDR52)
sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
sdhci_set_uhs_signaling(host, timing);
}
static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
{
sdhci_reset(host, mask);
if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
sdhci_at91_set_force_card_detect(host);
}
static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
.set_clock = sdhci_at91_set_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_at91_reset,
.set_uhs_signaling = sdhci_at91_set_uhs_signaling,
.set_power = sdhci_at91_set_power,
};
static const struct sdhci_pltfm_data soc_data_sama5d2 = {
.ops = &sdhci_at91_sama5d2_ops,
};
static const struct of_device_id sdhci_at91_dt_match[] = {
{ .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
{}
};
MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
static int sdhci_at91_set_clks_presets(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
int ret;
unsigned int caps0, caps1;
unsigned int clk_base, clk_mul;
unsigned int gck_rate, real_gck_rate;
unsigned int preset_div;
/*
* The mult clock is provided by as a generated clock by the PMC
* controller. In order to set the rate of gck, we have to get the
* base clock rate and the clock mult from capabilities.
*/
clk_prepare_enable(priv->hclock);
caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
gck_rate = clk_base * 1000000 * (clk_mul + 1);
ret = clk_set_rate(priv->gck, gck_rate);
if (ret < 0) {
dev_err(dev, "failed to set gck");
clk_disable_unprepare(priv->hclock);
return ret;
}
/*
* We need to check if we have the requested rate for gck because in
* some cases this rate could be not supported. If it happens, the rate
* is the closest one gck can provide. We have to update the value
* of clk mul.
*/
real_gck_rate = clk_get_rate(priv->gck);
if (real_gck_rate != gck_rate) {
clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
caps1 &= (~SDHCI_CLOCK_MUL_MASK);
caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) &
SDHCI_CLOCK_MUL_MASK);
/* Set capabilities in r/w mode. */
writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN,
host->ioaddr + SDMMC_CACR);
writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
/* Set capabilities in ro mode. */
writel(0, host->ioaddr + SDMMC_CACR);
dev_info(dev, "update clk mul to %u as gck rate is %u Hz\n",
clk_mul, real_gck_rate);
}
/*
* We have to set preset values because it depends on the clk_mul
* value. Moreover, SDR104 is supported in a degraded mode since the
* maximum sd clock value is 120 MHz instead of 208 MHz. For that
* reason, we need to use presets to support SDR104.
*/
preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1;
writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
host->ioaddr + SDHCI_PRESET_FOR_SDR12);
preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
host->ioaddr + SDHCI_PRESET_FOR_SDR25);
preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1;
writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
host->ioaddr + SDHCI_PRESET_FOR_SDR50);
preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1;
writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
host->ioaddr + SDHCI_PRESET_FOR_SDR104);
preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
host->ioaddr + SDHCI_PRESET_FOR_DDR50);
clk_prepare_enable(priv->mainck);
clk_prepare_enable(priv->gck);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int sdhci_at91_suspend(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
int ret;
ret = pm_runtime_force_suspend(dev);
priv->restore_needed = true;
return ret;
}
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_PM
static int sdhci_at91_runtime_suspend(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
int ret;
ret = sdhci_runtime_suspend_host(host);
if (host->tuning_mode != SDHCI_TUNING_MODE_3)
mmc_retune_needed(host->mmc);
clk_disable_unprepare(priv->gck);
clk_disable_unprepare(priv->hclock);
clk_disable_unprepare(priv->mainck);
return ret;
}
static int sdhci_at91_runtime_resume(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
int ret;
if (priv->restore_needed) {
ret = sdhci_at91_set_clks_presets(dev);
if (ret)
return ret;
priv->restore_needed = false;
goto out;
}
ret = clk_prepare_enable(priv->mainck);
if (ret) {
dev_err(dev, "can't enable mainck\n");
return ret;
}
ret = clk_prepare_enable(priv->hclock);
if (ret) {
dev_err(dev, "can't enable hclock\n");
return ret;
}
ret = clk_prepare_enable(priv->gck);
if (ret) {
dev_err(dev, "can't enable gck\n");
return ret;
}
out:
return sdhci_runtime_resume_host(host);
}
#endif /* CONFIG_PM */
static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(sdhci_at91_suspend, pm_runtime_force_resume)
SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
sdhci_at91_runtime_resume,
NULL)
};
static int sdhci_at91_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
const struct sdhci_pltfm_data *soc_data;
struct sdhci_host *host;
struct sdhci_pltfm_host *pltfm_host;
struct sdhci_at91_priv *priv;
int ret;
match = of_match_device(sdhci_at91_dt_match, &pdev->dev);
if (!match)
return -EINVAL;
soc_data = match->data;
host = sdhci_pltfm_init(pdev, soc_data, sizeof(*priv));
if (IS_ERR(host))
return PTR_ERR(host);
pltfm_host = sdhci_priv(host);
priv = sdhci_pltfm_priv(pltfm_host);
priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
if (IS_ERR(priv->mainck)) {
dev_err(&pdev->dev, "failed to get baseclk\n");
return PTR_ERR(priv->mainck);
}
priv->hclock = devm_clk_get(&pdev->dev, "hclock");
if (IS_ERR(priv->hclock)) {
dev_err(&pdev->dev, "failed to get hclock\n");
return PTR_ERR(priv->hclock);
}
priv->gck = devm_clk_get(&pdev->dev, "multclk");
if (IS_ERR(priv->gck)) {
dev_err(&pdev->dev, "failed to get multclk\n");
return PTR_ERR(priv->gck);
}
ret = sdhci_at91_set_clks_presets(&pdev->dev);
if (ret)
goto sdhci_pltfm_free;
priv->restore_needed = false;
ret = mmc_of_parse(host->mmc);
if (ret)
goto clocks_disable_unprepare;
sdhci_get_of_property(pdev);
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
pm_runtime_use_autosuspend(&pdev->dev);
ret = sdhci_add_host(host);
if (ret)
goto pm_runtime_disable;
/*
* When calling sdhci_runtime_suspend_host(), the sdhci layer makes
* the assumption that all the clocks of the controller are disabled.
* It means we can't get irq from it when it is runtime suspended.
* For that reason, it is not planned to wake-up on a card detect irq
* from the controller.
* If we want to use runtime PM and to be able to wake-up on card
* insertion, we have to use a GPIO for the card detection or we can
* use polling. Be aware that using polling will resume/suspend the
* controller between each attempt.
* Disable SDHCI_QUIRK_BROKEN_CARD_DETECTION to be sure nobody tries
* to enable polling via device tree with broken-cd property.
*/
if (mmc_card_is_removable(host->mmc) &&
mmc_gpio_get_cd(host->mmc) < 0) {
host->mmc->caps |= MMC_CAP_NEEDS_POLL;
host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
}
/*
* If the device attached to the MMC bus is not removable, it is safer
* to set the Force Card Detect bit. People often don't connect the
* card detect signal and use this pin for another purpose. If the card
* detect pin is not muxed to SDHCI controller, a default value is
* used. This value can be different from a SoC revision to another
* one. Problems come when this default value is not card present. To
* avoid this case, if the device is non removable then the card
* detection procedure using the SDMCC_CD signal is bypassed.
* This bit is reset when a software reset for all command is performed
* so we need to implement our own reset function to set back this bit.
*/
if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
sdhci_at91_set_force_card_detect(host);
pm_runtime_put_autosuspend(&pdev->dev);
return 0;
pm_runtime_disable:
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
clocks_disable_unprepare:
clk_disable_unprepare(priv->gck);
clk_disable_unprepare(priv->mainck);
clk_disable_unprepare(priv->hclock);
sdhci_pltfm_free:
sdhci_pltfm_free(pdev);
return ret;
}
static int sdhci_at91_remove(struct platform_device *pdev)
{
struct sdhci_host *host = platform_get_drvdata(pdev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
struct clk *gck = priv->gck;
struct clk *hclock = priv->hclock;
struct clk *mainck = priv->mainck;
pm_runtime_get_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
sdhci_pltfm_unregister(pdev);
clk_disable_unprepare(gck);
clk_disable_unprepare(hclock);
clk_disable_unprepare(mainck);
return 0;
}
static struct platform_driver sdhci_at91_driver = {
.driver = {
.name = "sdhci-at91",
.of_match_table = sdhci_at91_dt_match,
.pm = &sdhci_at91_dev_pm_ops,
},
.probe = sdhci_at91_probe,
.remove = sdhci_at91_remove,
};
module_platform_driver(sdhci_at91_driver);
MODULE_DESCRIPTION("SDHCI driver for at91");
MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
MODULE_LICENSE("GPL v2");
