d97a1e5d7c
simple-pwrseq and emmc-pwrseq drivers rely on platform_device structure from of_find_device_by_node(), this works mostly. But, as there is no driver associated with this devices, cases like default/init pinctrl setup would never be performed by pwrseq. This becomes problem when the gpios used in pwrseq require pinctrl setup. Currently most of the common pinctrl setup is done in drivers/base/pinctrl.c by pinctrl_bind_pins(). There are two ways to solve this issue on either convert pwrseq drivers to a proper platform drivers or copy the exact code from pcintrl_bind_pins(). I prefer converting pwrseq to proper drivers so that other cases like setting up clks/parents from dt would also be possible. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
120 lines
3 KiB
C
120 lines
3 KiB
C
/*
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* Copyright (C) 2015, Samsung Electronics Co., Ltd.
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*
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* Author: Marek Szyprowski <m.szyprowski@samsung.com>
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*
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* License terms: GNU General Public License (GPL) version 2
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*
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* Simple eMMC hardware reset provider
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*/
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#include <linux/delay.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/gpio/consumer.h>
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#include <linux/reboot.h>
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#include <linux/mmc/host.h>
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#include "pwrseq.h"
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struct mmc_pwrseq_emmc {
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struct mmc_pwrseq pwrseq;
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struct notifier_block reset_nb;
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struct gpio_desc *reset_gpio;
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};
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#define to_pwrseq_emmc(p) container_of(p, struct mmc_pwrseq_emmc, pwrseq)
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static void __mmc_pwrseq_emmc_reset(struct mmc_pwrseq_emmc *pwrseq)
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{
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gpiod_set_value(pwrseq->reset_gpio, 1);
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udelay(1);
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gpiod_set_value(pwrseq->reset_gpio, 0);
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udelay(200);
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}
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static void mmc_pwrseq_emmc_reset(struct mmc_host *host)
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{
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struct mmc_pwrseq_emmc *pwrseq = to_pwrseq_emmc(host->pwrseq);
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__mmc_pwrseq_emmc_reset(pwrseq);
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}
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static int mmc_pwrseq_emmc_reset_nb(struct notifier_block *this,
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unsigned long mode, void *cmd)
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{
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struct mmc_pwrseq_emmc *pwrseq = container_of(this,
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struct mmc_pwrseq_emmc, reset_nb);
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__mmc_pwrseq_emmc_reset(pwrseq);
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return NOTIFY_DONE;
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}
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static const struct mmc_pwrseq_ops mmc_pwrseq_emmc_ops = {
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.post_power_on = mmc_pwrseq_emmc_reset,
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};
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static int mmc_pwrseq_emmc_probe(struct platform_device *pdev)
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{
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struct mmc_pwrseq_emmc *pwrseq;
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struct device *dev = &pdev->dev;
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pwrseq = devm_kzalloc(dev, sizeof(*pwrseq), GFP_KERNEL);
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if (!pwrseq)
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return -ENOMEM;
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pwrseq->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
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if (IS_ERR(pwrseq->reset_gpio))
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return PTR_ERR(pwrseq->reset_gpio);
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/*
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* register reset handler to ensure emmc reset also from
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* emergency_reboot(), priority 255 is the highest priority
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* so it will be executed before any system reboot handler.
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*/
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pwrseq->reset_nb.notifier_call = mmc_pwrseq_emmc_reset_nb;
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pwrseq->reset_nb.priority = 255;
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register_restart_handler(&pwrseq->reset_nb);
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pwrseq->pwrseq.ops = &mmc_pwrseq_emmc_ops;
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pwrseq->pwrseq.dev = dev;
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pwrseq->pwrseq.owner = THIS_MODULE;
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platform_set_drvdata(pdev, pwrseq);
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return mmc_pwrseq_register(&pwrseq->pwrseq);
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}
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static int mmc_pwrseq_emmc_remove(struct platform_device *pdev)
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{
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struct mmc_pwrseq_emmc *pwrseq = platform_get_drvdata(pdev);
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unregister_restart_handler(&pwrseq->reset_nb);
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mmc_pwrseq_unregister(&pwrseq->pwrseq);
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return 0;
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}
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static const struct of_device_id mmc_pwrseq_emmc_of_match[] = {
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{ .compatible = "mmc-pwrseq-emmc",},
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{/* sentinel */},
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};
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MODULE_DEVICE_TABLE(of, mmc_pwrseq_emmc_of_match);
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static struct platform_driver mmc_pwrseq_emmc_driver = {
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.probe = mmc_pwrseq_emmc_probe,
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.remove = mmc_pwrseq_emmc_remove,
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.driver = {
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.name = "pwrseq_emmc",
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.of_match_table = mmc_pwrseq_emmc_of_match,
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},
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};
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module_platform_driver(mmc_pwrseq_emmc_driver);
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MODULE_LICENSE("GPL v2");
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