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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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9a9b1c618d
clk_prepare/unprepare (and indirectly clk_prepare_enable/disable_unprepare)
may sleep and thus cannot be called in critical section.
This patch fix a bug introduced by commit
6f0d94790e
where clk_disable_unprepare was
called with user_lock hold.
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
225 lines
4.9 KiB
C
225 lines
4.9 KiB
C
/*
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* Atmel SSC driver
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*
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* Copyright (C) 2007 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/platform_device.h>
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#include <linux/list.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/spinlock.h>
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#include <linux/atmel-ssc.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/pinctrl/consumer.h>
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/* Serialize access to ssc_list and user count */
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static DEFINE_SPINLOCK(user_lock);
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static LIST_HEAD(ssc_list);
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struct ssc_device *ssc_request(unsigned int ssc_num)
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{
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int ssc_valid = 0;
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struct ssc_device *ssc;
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spin_lock(&user_lock);
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list_for_each_entry(ssc, &ssc_list, list) {
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if (ssc->pdev->dev.of_node) {
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if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
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== ssc_num) {
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ssc_valid = 1;
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break;
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}
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} else if (ssc->pdev->id == ssc_num) {
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ssc_valid = 1;
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break;
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}
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}
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if (!ssc_valid) {
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spin_unlock(&user_lock);
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pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
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return ERR_PTR(-ENODEV);
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}
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if (ssc->user) {
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spin_unlock(&user_lock);
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dev_dbg(&ssc->pdev->dev, "module busy\n");
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return ERR_PTR(-EBUSY);
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}
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ssc->user++;
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spin_unlock(&user_lock);
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clk_prepare_enable(ssc->clk);
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return ssc;
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}
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EXPORT_SYMBOL(ssc_request);
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void ssc_free(struct ssc_device *ssc)
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{
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bool disable_clk = true;
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spin_lock(&user_lock);
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if (ssc->user)
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ssc->user--;
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else {
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disable_clk = false;
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dev_dbg(&ssc->pdev->dev, "device already free\n");
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}
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spin_unlock(&user_lock);
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if (disable_clk)
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clk_disable_unprepare(ssc->clk);
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}
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EXPORT_SYMBOL(ssc_free);
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static struct atmel_ssc_platform_data at91rm9200_config = {
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.use_dma = 0,
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};
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static struct atmel_ssc_platform_data at91sam9g45_config = {
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.use_dma = 1,
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};
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static const struct platform_device_id atmel_ssc_devtypes[] = {
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{
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.name = "at91rm9200_ssc",
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.driver_data = (unsigned long) &at91rm9200_config,
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}, {
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.name = "at91sam9g45_ssc",
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.driver_data = (unsigned long) &at91sam9g45_config,
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}, {
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/* sentinel */
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}
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};
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#ifdef CONFIG_OF
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static const struct of_device_id atmel_ssc_dt_ids[] = {
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{
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.compatible = "atmel,at91rm9200-ssc",
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.data = &at91rm9200_config,
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}, {
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.compatible = "atmel,at91sam9g45-ssc",
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.data = &at91sam9g45_config,
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}, {
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/* sentinel */
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}
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};
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MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
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#endif
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static inline const struct atmel_ssc_platform_data * __init
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atmel_ssc_get_driver_data(struct platform_device *pdev)
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{
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if (pdev->dev.of_node) {
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const struct of_device_id *match;
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match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node);
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if (match == NULL)
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return NULL;
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return match->data;
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}
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return (struct atmel_ssc_platform_data *)
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platform_get_device_id(pdev)->driver_data;
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}
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static int ssc_probe(struct platform_device *pdev)
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{
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struct resource *regs;
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struct ssc_device *ssc;
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const struct atmel_ssc_platform_data *plat_dat;
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struct pinctrl *pinctrl;
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pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
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if (IS_ERR(pinctrl)) {
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dev_err(&pdev->dev, "Failed to request pinctrl\n");
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return PTR_ERR(pinctrl);
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}
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ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
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if (!ssc) {
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dev_dbg(&pdev->dev, "out of memory\n");
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return -ENOMEM;
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}
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ssc->pdev = pdev;
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plat_dat = atmel_ssc_get_driver_data(pdev);
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if (!plat_dat)
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return -ENODEV;
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ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat;
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regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
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if (IS_ERR(ssc->regs))
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return PTR_ERR(ssc->regs);
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ssc->phybase = regs->start;
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ssc->clk = devm_clk_get(&pdev->dev, "pclk");
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if (IS_ERR(ssc->clk)) {
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dev_dbg(&pdev->dev, "no pclk clock defined\n");
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return -ENXIO;
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}
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/* disable all interrupts */
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clk_prepare_enable(ssc->clk);
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ssc_writel(ssc->regs, IDR, -1);
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ssc_readl(ssc->regs, SR);
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clk_disable_unprepare(ssc->clk);
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ssc->irq = platform_get_irq(pdev, 0);
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if (!ssc->irq) {
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dev_dbg(&pdev->dev, "could not get irq\n");
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return -ENXIO;
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}
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spin_lock(&user_lock);
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list_add_tail(&ssc->list, &ssc_list);
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spin_unlock(&user_lock);
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platform_set_drvdata(pdev, ssc);
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dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
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ssc->regs, ssc->irq);
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return 0;
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}
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static int ssc_remove(struct platform_device *pdev)
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{
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struct ssc_device *ssc = platform_get_drvdata(pdev);
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spin_lock(&user_lock);
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list_del(&ssc->list);
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spin_unlock(&user_lock);
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return 0;
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}
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static struct platform_driver ssc_driver = {
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.driver = {
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.name = "ssc",
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(atmel_ssc_dt_ids),
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},
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.id_table = atmel_ssc_devtypes,
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.probe = ssc_probe,
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.remove = ssc_remove,
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};
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module_platform_driver(ssc_driver);
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MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
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MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:ssc");
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