linux/drivers/mmc/host/sdhci-of-at91.c
ludovic.desroches@atmel.com 64e5cd7231 mmc: sdhci-of-at91: fix wake-up issue when using runtime pm
It is impossible to wake-up on card detect event because when sdhci
controller is runtime suspended, it is assumed that all clocks are
disabled so we can't get irqs.
If the device is removable and there is no gpio to manage the card
detection then polling is used. It doesn't mean card detection is broken.
It is curently we only way to wake-up on card event if using runtime pm.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-03-18 09:12:32 +01:00

281 lines
8.0 KiB
C

/*
* Atmel SDMMC controller driver.
*
* Copyright (C) 2015 Atmel,
* 2015 Ludovic Desroches <ludovic.desroches@atmel.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.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_CACR 0x230
#define SDMMC_CACR_CAPWREN BIT(0)
#define SDMMC_CACR_KEY (0x46 << 8)
struct sdhci_at91_priv {
struct clk *hclock;
struct clk *gck;
struct clk *mainck;
};
static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
.set_clock = sdhci_set_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
};
static const struct sdhci_pltfm_data soc_data_sama5d2 = {
.ops = &sdhci_at91_sama5d2_ops,
.quirks2 = SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST,
};
static const struct of_device_id sdhci_at91_dt_match[] = {
{ .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
{}
};
#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);
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;
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;
}
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(pm_runtime_force_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;
unsigned int caps0, caps1;
unsigned int clk_base, clk_mul;
unsigned int gck_rate, real_gck_rate;
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);
}
/*
* 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(&pdev->dev, "failed to set gck");
goto hclock_disable_unprepare;
}
/*
* 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(&pdev->dev, "update clk mul to %u as gck rate is %u Hz\n",
clk_mul, real_gck_rate);
}
clk_prepare_enable(priv->mainck);
clk_prepare_enable(priv->gck);
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 (!(host->mmc->caps & MMC_CAP_NONREMOVABLE) &&
IS_ERR_VALUE(mmc_gpio_get_cd(host->mmc))) {
host->mmc->caps |= MMC_CAP_NEEDS_POLL;
host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
}
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);
hclock_disable_unprepare:
clk_disable_unprepare(priv->hclock);
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");