/* * Atmel SSC driver * * Copyright (C) 2007 Atmel Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/platform_device.h> #include <linux/list.h> #include <linux/clk.h> #include <linux/err.h> #include <linux/io.h> #include <linux/spinlock.h> #include <linux/atmel-ssc.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> /* Serialize access to ssc_list and user count */ static DEFINE_SPINLOCK(user_lock); static LIST_HEAD(ssc_list); struct ssc_device *ssc_request(unsigned int ssc_num) { int ssc_valid = 0; struct ssc_device *ssc; spin_lock(&user_lock); list_for_each_entry(ssc, &ssc_list, list) { if (ssc->pdev->dev.of_node) { if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc") == ssc_num) { ssc_valid = 1; break; } } else if (ssc->pdev->id == ssc_num) { ssc_valid = 1; break; } } if (!ssc_valid) { spin_unlock(&user_lock); pr_err("ssc: ssc%d platform device is missing\n", ssc_num); return ERR_PTR(-ENODEV); } if (ssc->user) { spin_unlock(&user_lock); dev_dbg(&ssc->pdev->dev, "module busy\n"); return ERR_PTR(-EBUSY); } ssc->user++; spin_unlock(&user_lock); clk_enable(ssc->clk); return ssc; } EXPORT_SYMBOL(ssc_request); void ssc_free(struct ssc_device *ssc) { spin_lock(&user_lock); if (ssc->user) { ssc->user--; clk_disable(ssc->clk); } else { dev_dbg(&ssc->pdev->dev, "device already free\n"); } spin_unlock(&user_lock); } EXPORT_SYMBOL(ssc_free); static struct atmel_ssc_platform_data at91rm9200_config = { .use_dma = 0, }; static struct atmel_ssc_platform_data at91sam9g45_config = { .use_dma = 1, }; static const struct platform_device_id atmel_ssc_devtypes[] = { { .name = "at91rm9200_ssc", .driver_data = (unsigned long) &at91rm9200_config, }, { .name = "at91sam9g45_ssc", .driver_data = (unsigned long) &at91sam9g45_config, }, { /* sentinel */ } }; #ifdef CONFIG_OF static const struct of_device_id atmel_ssc_dt_ids[] = { { .compatible = "atmel,at91rm9200-ssc", .data = &at91rm9200_config, }, { .compatible = "atmel,at91sam9g45-ssc", .data = &at91sam9g45_config, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids); #endif static inline const struct atmel_ssc_platform_data * __init atmel_ssc_get_driver_data(struct platform_device *pdev) { if (pdev->dev.of_node) { const struct of_device_id *match; match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node); if (match == NULL) return NULL; return match->data; } return (struct atmel_ssc_platform_data *) platform_get_device_id(pdev)->driver_data; } static int ssc_probe(struct platform_device *pdev) { struct resource *regs; struct ssc_device *ssc; const struct atmel_ssc_platform_data *plat_dat; struct pinctrl *pinctrl; pinctrl = devm_pinctrl_get_select_default(&pdev->dev); if (IS_ERR(pinctrl)) { dev_err(&pdev->dev, "Failed to request pinctrl\n"); return PTR_ERR(pinctrl); } ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL); if (!ssc) { dev_dbg(&pdev->dev, "out of memory\n"); return -ENOMEM; } ssc->pdev = pdev; plat_dat = atmel_ssc_get_driver_data(pdev); if (!plat_dat) return -ENODEV; ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat; regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!regs) { dev_dbg(&pdev->dev, "no mmio resource defined\n"); return -ENXIO; } ssc->regs = devm_request_and_ioremap(&pdev->dev, regs); if (!ssc->regs) { dev_dbg(&pdev->dev, "ioremap failed\n"); return -EINVAL; } ssc->phybase = regs->start; ssc->clk = devm_clk_get(&pdev->dev, "pclk"); if (IS_ERR(ssc->clk)) { dev_dbg(&pdev->dev, "no pclk clock defined\n"); return -ENXIO; } /* disable all interrupts */ clk_enable(ssc->clk); ssc_writel(ssc->regs, IDR, ~0UL); ssc_readl(ssc->regs, SR); clk_disable(ssc->clk); ssc->irq = platform_get_irq(pdev, 0); if (!ssc->irq) { dev_dbg(&pdev->dev, "could not get irq\n"); return -ENXIO; } spin_lock(&user_lock); list_add_tail(&ssc->list, &ssc_list); spin_unlock(&user_lock); platform_set_drvdata(pdev, ssc); dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n", ssc->regs, ssc->irq); return 0; } static int ssc_remove(struct platform_device *pdev) { struct ssc_device *ssc = platform_get_drvdata(pdev); spin_lock(&user_lock); list_del(&ssc->list); spin_unlock(&user_lock); return 0; } static struct platform_driver ssc_driver = { .driver = { .name = "ssc", .owner = THIS_MODULE, .of_match_table = of_match_ptr(atmel_ssc_dt_ids), }, .id_table = atmel_ssc_devtypes, .probe = ssc_probe, .remove = ssc_remove, }; module_platform_driver(ssc_driver); MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>"); MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:ssc");