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>
142 lines
3.6 KiB
C
142 lines
3.6 KiB
C
/*
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* Copyright (C) 2014 Linaro Ltd
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*
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* Author: Ulf Hansson <ulf.hansson@linaro.org>
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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 MMC power sequence management
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*/
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#include <linux/clk.h>
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#include <linux/init.h>
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#include <linux/kernel.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/mmc/host.h>
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#include "pwrseq.h"
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struct mmc_pwrseq_simple {
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struct mmc_pwrseq pwrseq;
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bool clk_enabled;
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struct clk *ext_clk;
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struct gpio_descs *reset_gpios;
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};
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#define to_pwrseq_simple(p) container_of(p, struct mmc_pwrseq_simple, pwrseq)
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static void mmc_pwrseq_simple_set_gpios_value(struct mmc_pwrseq_simple *pwrseq,
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int value)
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{
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struct gpio_descs *reset_gpios = pwrseq->reset_gpios;
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if (!IS_ERR(reset_gpios)) {
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int i;
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int values[reset_gpios->ndescs];
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for (i = 0; i < reset_gpios->ndescs; i++)
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values[i] = value;
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gpiod_set_array_value_cansleep(
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reset_gpios->ndescs, reset_gpios->desc, values);
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}
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}
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static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
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{
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struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
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if (!IS_ERR(pwrseq->ext_clk) && !pwrseq->clk_enabled) {
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clk_prepare_enable(pwrseq->ext_clk);
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pwrseq->clk_enabled = true;
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}
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mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
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}
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static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
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{
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struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
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mmc_pwrseq_simple_set_gpios_value(pwrseq, 0);
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}
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static void mmc_pwrseq_simple_power_off(struct mmc_host *host)
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{
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struct mmc_pwrseq_simple *pwrseq = to_pwrseq_simple(host->pwrseq);
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mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
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if (!IS_ERR(pwrseq->ext_clk) && pwrseq->clk_enabled) {
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clk_disable_unprepare(pwrseq->ext_clk);
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pwrseq->clk_enabled = false;
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}
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}
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static const struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
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.pre_power_on = mmc_pwrseq_simple_pre_power_on,
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.post_power_on = mmc_pwrseq_simple_post_power_on,
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.power_off = mmc_pwrseq_simple_power_off,
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};
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static const struct of_device_id mmc_pwrseq_simple_of_match[] = {
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{ .compatible = "mmc-pwrseq-simple",},
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{/* sentinel */},
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};
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MODULE_DEVICE_TABLE(of, mmc_pwrseq_simple_of_match);
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static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
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{
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struct mmc_pwrseq_simple *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->ext_clk = devm_clk_get(dev, "ext_clock");
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if (IS_ERR(pwrseq->ext_clk) && PTR_ERR(pwrseq->ext_clk) != -ENOENT)
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return PTR_ERR(pwrseq->ext_clk);
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pwrseq->reset_gpios = devm_gpiod_get_array(dev, "reset",
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GPIOD_OUT_HIGH);
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if (IS_ERR(pwrseq->reset_gpios) &&
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PTR_ERR(pwrseq->reset_gpios) != -ENOENT &&
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PTR_ERR(pwrseq->reset_gpios) != -ENOSYS) {
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return PTR_ERR(pwrseq->reset_gpios);
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}
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pwrseq->pwrseq.dev = dev;
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pwrseq->pwrseq.ops = &mmc_pwrseq_simple_ops;
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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_simple_remove(struct platform_device *pdev)
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{
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struct mmc_pwrseq_simple *pwrseq = platform_get_drvdata(pdev);
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mmc_pwrseq_unregister(&pwrseq->pwrseq);
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return 0;
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}
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static struct platform_driver mmc_pwrseq_simple_driver = {
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.probe = mmc_pwrseq_simple_probe,
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.remove = mmc_pwrseq_simple_remove,
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.driver = {
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.name = "pwrseq_simple",
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.of_match_table = mmc_pwrseq_simple_of_match,
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},
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};
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module_platform_driver(mmc_pwrseq_simple_driver);
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MODULE_LICENSE("GPL v2");
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