mmc: mvsdio: implement a Device Tree binding

This patch adds a simple Device Tree binding for the mvsdio driver, as
well as the necessary documentation for it. Compatibility with non-DT
platforms is preserved, by keeping the platform_data based
initialization.

We introduce a small difference between non-DT and DT platforms: DT
platforms are required to provide a clocks = <...> property, which the
driver uses to get the frequency of the clock that goes to the SDIO
IP. The behaviour on non-DT platforms is kept unchanged: a clock
reference is not mandatory, but the clock frequency must be passed in
the "clock" field of the mvsdio_platform_data structure.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Stefan Peter <s.peter@mpl.ch>
Tested-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Thomas Petazzoni 2013-01-16 14:13:59 +01:00 committed by Chris Ball
parent 07728b77c0
commit 111936ff3b
2 changed files with 66 additions and 15 deletions

View file

@ -0,0 +1,17 @@
* Marvell orion-sdio controller
This file documents differences between the core properties in mmc.txt
and the properties used by the orion-sdio driver.
- compatible: Should be "marvell,orion-sdio"
- clocks: reference to the clock of the SDIO interface
Example:
mvsdio@d00d4000 {
compatible = "marvell,orion-sdio";
reg = <0xd00d4000 0x200>;
interrupts = <54>;
clocks = <&gateclk 17>;
status = "disabled";
};

View file

@ -21,6 +21,8 @@
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/mmc/host.h>
#include <linux/mmc/slot-gpio.h>
@ -681,17 +683,17 @@ mv_conf_mbus_windows(struct mvsd_host *host,
static int __init mvsd_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct mmc_host *mmc = NULL;
struct mvsd_host *host = NULL;
const struct mvsdio_platform_data *mvsd_data;
const struct mbus_dram_target_info *dram;
struct resource *r;
int ret, irq;
int gpio_card_detect, gpio_write_protect;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
irq = platform_get_irq(pdev, 0);
mvsd_data = pdev->dev.platform_data;
if (!r || irq < 0 || !mvsd_data)
if (!r || irq < 0)
return -ENXIO;
mmc = mmc_alloc_host(sizeof(struct mvsd_host), &pdev->dev);
@ -703,8 +705,39 @@ static int __init mvsd_probe(struct platform_device *pdev)
host = mmc_priv(mmc);
host->mmc = mmc;
host->dev = &pdev->dev;
host->base_clock = mvsd_data->clock / 2;
host->clk = ERR_PTR(-EINVAL);
/*
* Some non-DT platforms do not pass a clock, and the clock
* frequency is passed through platform_data. On DT platforms,
* a clock must always be passed, even if there is no gatable
* clock associated to the SDIO interface (it can simply be a
* fixed rate clock).
*/
host->clk = devm_clk_get(&pdev->dev, NULL);
if (!IS_ERR(host->clk))
clk_prepare_enable(host->clk);
if (np) {
if (IS_ERR(host->clk)) {
dev_err(&pdev->dev, "DT platforms must have a clock associated\n");
ret = -EINVAL;
goto out;
}
host->base_clock = clk_get_rate(host->clk) / 2;
gpio_card_detect = of_get_named_gpio(np, "cd-gpios", 0);
gpio_write_protect = of_get_named_gpio(np, "wp-gpios", 0);
} else {
const struct mvsdio_platform_data *mvsd_data;
mvsd_data = pdev->dev.platform_data;
if (!mvsd_data) {
ret = -ENXIO;
goto out;
}
host->base_clock = mvsd_data->clock / 2;
gpio_card_detect = mvsd_data->gpio_card_detect;
gpio_write_protect = mvsd_data->gpio_write_protect;
}
mmc->ops = &mvsd_ops;
@ -743,20 +776,14 @@ static int __init mvsd_probe(struct platform_device *pdev)
goto out;
}
/* Not all platforms can gate the clock, so it is not
an error if the clock does not exists. */
host->clk = devm_clk_get(&pdev->dev, NULL);
if (!IS_ERR(host->clk))
clk_prepare_enable(host->clk);
if (gpio_is_valid(mvsd_data->gpio_card_detect)) {
ret = mmc_gpio_request_cd(mmc, mvsd_data->gpio_card_detect);
if (gpio_is_valid(gpio_card_detect)) {
ret = mmc_gpio_request_cd(mmc, gpio_card_detect);
if (ret)
goto out;
} else
mmc->caps |= MMC_CAP_NEEDS_POLL;
mmc_gpio_request_ro(mmc, mvsd_data->gpio_write_protect);
mmc_gpio_request_ro(mmc, gpio_write_protect);
setup_timer(&host->timer, mvsd_timeout_timer, (unsigned long)host);
platform_set_drvdata(pdev, mmc);
@ -768,7 +795,7 @@ static int __init mvsd_probe(struct platform_device *pdev)
mmc_hostname(mmc), DRIVER_NAME);
if (!(mmc->caps & MMC_CAP_NEEDS_POLL))
printk("using GPIO %d for card detection\n",
mvsd_data->gpio_card_detect);
gpio_card_detect);
else
printk("lacking card detect (fall back to polling)\n");
return 0;
@ -832,12 +859,19 @@ static int mvsd_resume(struct platform_device *dev)
#define mvsd_resume NULL
#endif
static const struct of_device_id mvsdio_dt_ids[] = {
{ .compatible = "marvell,orion-sdio" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mvsdio_dt_ids);
static struct platform_driver mvsd_driver = {
.remove = __exit_p(mvsd_remove),
.suspend = mvsd_suspend,
.resume = mvsd_resume,
.driver = {
.name = DRIVER_NAME,
.of_match_table = mvsdio_dt_ids,
},
};