diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/misc/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/misc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/misc/atmel-ssc.c | 174 |
3 files changed, 187 insertions, 0 deletions
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 73e248fb2ff1..346c44eff95e 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -203,4 +203,16 @@ config THINKPAD_ACPI_BAY If you are not sure, say Y here. +config ATMEL_SSC + tristate "Device driver for Atmel SSC peripheral" + depends on AVR32 || ARCH_AT91 + ---help--- + This option enables device driver support for Atmel Syncronized + Serial Communication peripheral (SSC). + + The SSC peripheral supports a wide variety of serial frame based + communications, i.e. I2S, SPI, etc. + + If unsure, say N. + endif # MISC_DEVICES diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index b5ce0e3dba86..a24c61475c2f 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_IBM_ASM) += ibmasm/ obj-$(CONFIG_HDPU_FEATURES) += hdpuftrs/ obj-$(CONFIG_MSI_LAPTOP) += msi-laptop.o obj-$(CONFIG_ASUS_LAPTOP) += asus-laptop.o +obj-$(CONFIG_ATMEL_SSC) += atmel-ssc.o obj-$(CONFIG_LKDTM) += lkdtm.o obj-$(CONFIG_TIFM_CORE) += tifm_core.o obj-$(CONFIG_TIFM_7XX1) += tifm_7xx1.o diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c new file mode 100644 index 000000000000..058ccac700d0 --- /dev/null +++ b/drivers/misc/atmel-ssc.c @@ -0,0 +1,174 @@ +/* + * 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/list.h> +#include <linux/spinlock.h> +#include <linux/atmel-ssc.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->id == ssc_num) { + ssc_valid = 1; + break; + } + } + + if (!ssc_valid) { + spin_unlock(&user_lock); + dev_dbg(&ssc->pdev->dev, "could not find requested device\n"); + 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 int __init ssc_probe(struct platform_device *pdev) +{ + int retval = 0; + struct resource *regs; + struct ssc_device *ssc; + + ssc = kzalloc(sizeof(struct ssc_device), GFP_KERNEL); + if (!ssc) { + dev_dbg(&pdev->dev, "out of memory\n"); + retval = -ENOMEM; + goto out; + } + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!regs) { + dev_dbg(&pdev->dev, "no mmio resource defined\n"); + retval = -ENXIO; + goto out_free; + } + + ssc->clk = clk_get(&pdev->dev, "pclk"); + if (IS_ERR(ssc->clk)) { + dev_dbg(&pdev->dev, "no pclk clock defined\n"); + retval = -ENXIO; + goto out_free; + } + + ssc->pdev = pdev; + ssc->regs = ioremap(regs->start, regs->end - regs->start + 1); + if (!ssc->regs) { + dev_dbg(&pdev->dev, "ioremap failed\n"); + retval = -EINVAL; + goto out_clk; + } + + /* 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"); + retval = -ENXIO; + goto out_unmap; + } + + 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); + + goto out; + +out_unmap: + iounmap(ssc->regs); +out_clk: + clk_put(ssc->clk); +out_free: + kfree(ssc); +out: + return retval; +} + +static int __devexit ssc_remove(struct platform_device *pdev) +{ + struct ssc_device *ssc = platform_get_drvdata(pdev); + + spin_lock(&user_lock); + iounmap(ssc->regs); + clk_put(ssc->clk); + list_del(&ssc->list); + kfree(ssc); + spin_unlock(&user_lock); + + return 0; +} + +static struct platform_driver ssc_driver = { + .remove = __devexit_p(ssc_remove), + .driver = { + .name = "ssc", + }, +}; + +static int __init ssc_init(void) +{ + return platform_driver_probe(&ssc_driver, ssc_probe); +} +module_init(ssc_init); + +static void __exit ssc_exit(void) +{ + platform_driver_unregister(&ssc_driver); +} +module_exit(ssc_exit); + +MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>"); +MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91"); +MODULE_LICENSE("GPL"); |