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![Bo Shen](/assets/img/avatar_default.png)
When SSC works in slave mode, according to the hardware design, the clock can get from TK pin, also can get from RK pin. So, add one parameter to choose where the clock from. Signed-off-by: Bo Shen <voice.shen@atmel.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Mark Brown <broonie@linaro.org>
222 lines
4.8 KiB
C
222 lines
4.8 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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/* 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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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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if (pdev->dev.of_node) {
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struct device_node *np = pdev->dev.of_node;
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ssc->clk_from_rk_pin =
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of_property_read_bool(np, "atmel,clk-from-rk-pin");
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}
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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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