diff options
Diffstat (limited to 'target/linux/at91/files/drivers/misc/at91-adc.c')
| -rw-r--r-- | target/linux/at91/files/drivers/misc/at91-adc.c | 355 |
1 files changed, 0 insertions, 355 deletions
diff --git a/target/linux/at91/files/drivers/misc/at91-adc.c b/target/linux/at91/files/drivers/misc/at91-adc.c deleted file mode 100644 index 90ea818..0000000 --- a/target/linux/at91/files/drivers/misc/at91-adc.c +++ /dev/null @@ -1,355 +0,0 @@ -/* - * Driver for ADC on Atmel AT91 SoC Family - * - * Copyright (C) 2010 Claudio Mignanti - c.mignanti@gmail.com - * Based on http://www.at91.com/forum/viewtopic.php/p,9409/#p9409 - * - * Copyright (C) 2010 Stefano Barbato - stefano@codesink.org - * - * 2010/05/18 Antonio Galea - * Sysfs device model, different drivers integration - * - * WISHLIST: - * - concurrent access control - * - add support for dynamic reconfiguration - * - hardware triggers - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation. - * - * --------------------------------------------------------------------------- -*/ - -#include <linux/cdev.h> -#include <linux/clk.h> -#include <linux/fs.h> -#include <linux/gpio.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/platform_device.h> -#include <linux/kernel.h> -#include <linux/smp_lock.h> - -#include <asm/io.h> - -#include "at91_adc.h" - -#define DRV_CLASS "at91_adc" - -#define ADC_REQUEST 1 //un-used atm -#define ADC_READ 2 -#define ADC_FREE 3 - -/* Device functions */ -#define at91_adc_read(reg) ioread32(at91_adc_base + (reg)) -#define at91_adc_write(reg, val) iowrite32((val), at91_adc_base + (reg)) -#define AT91_DEFAULT_CONFIG AT91_ADC_SHTIM | \ - AT91_ADC_STARTUP | \ - AT91_ADC_PRESCAL | \ - AT91_ADC_SLEEP - -static void at91_adc_device_release(struct device *dev) {} - -struct platform_device at91_adc_device = { - .name = "at91_adc", - .id = -1, - .dev.release = at91_adc_device_release, -}; - -struct clk *at91_adc_clk; -void __iomem *at91_adc_base; -void __iomem *at91_pioc_base; -static struct cdev *at91_adc_cdev = NULL; -static dev_t at91_adc_devno = 0; -static struct class *at91_adc_class = NULL; - -static int at91_adc_read_chan(int chan){ - int val, sr; - - if(chan<0 || chan>3){ - return -EINVAL; - } - /* disable pull-up resistor */ - iowrite32(1 << chan, at91_pioc_base + 0x60); - - at91_adc_write(AT91_ADC_CHER,AT91_ADC_CH(chan)); // Enable Channel - at91_adc_write(AT91_ADC_CR,AT91_ADC_START); //Start the ADC - - for(sr=0; !(sr & AT91_ADC_EOC(chan)); sr=at91_adc_read(AT91_ADC_SR)) - cpu_relax(); - - val=at91_adc_read(AT91_ADC_CHR(chan)) & AT91_ADC_DATA; //Read up to 10 bits - - return val; -} - -/* PC0 -> AD0 - PC1 -> AD1 - PC2 -> AD2 - PC3 -> AD3 */ -static int mux_chan (int chan, int operation) { - - int pin_chan; - - if(chan<0 || chan>3){ - return -EINVAL; - } - - switch (chan) { - case 0: - pin_chan=AT91_PIN_PC0; - break; - case 1: - pin_chan=AT91_PIN_PC1; - break; - case 2: - pin_chan=AT91_PIN_PC2; - break; - case 3: - pin_chan=AT91_PIN_PC3; - break; - default: - return -EINVAL; - } - - if (operation == 1) //request_chan - at91_set_A_periph(pin_chan, 0); //Mux PIN to GPIO - else //free_chan - at91_set_B_periph(pin_chan, 0); //Mux PIN to GPIO - - return 0; -} - -static int at91_adc_config(int requested_config){ - int actual_config; - - at91_adc_write(AT91_ADC_CR,AT91_ADC_SWRST); //Reset the ADC - at91_adc_write(AT91_ADC_MR,requested_config); //Mode setup - actual_config = at91_adc_read(AT91_ADC_MR); //Read it back - - return (requested_config==actual_config? 0: -EINVAL); -} - -/* Sysfs interface */ -static ssize_t at91_adc_chanX_show( - struct device *dev, struct device_attribute *attr, char *buf ){ - - ssize_t status = 0; - int chan = -1; - int value; - - if(strlen(attr->attr.name)==5 && strncmp(attr->attr.name,"chan",4)==0){ - chan = attr->attr.name[4]-'0'; - } - - if(chan<0 || chan>3){ - return -EIO; - } - - value = at91_adc_read_chan(chan); - status = sprintf(buf, "%d\n", value); - - return status; -} - -static DEVICE_ATTR(chan0, 0444, at91_adc_chanX_show, NULL); -static DEVICE_ATTR(chan1, 0444, at91_adc_chanX_show, NULL); -static DEVICE_ATTR(chan2, 0444, at91_adc_chanX_show, NULL); -static DEVICE_ATTR(chan3, 0444, at91_adc_chanX_show, NULL); - -static const struct attribute *at91_adc_dev_attrs[] = { - &dev_attr_chan0.attr, - &dev_attr_chan1.attr, - &dev_attr_chan2.attr, - &dev_attr_chan3.attr, - NULL, -}; - -static const struct attribute_group at91_adc_dev_attr_group = { - .attrs = (struct attribute **) at91_adc_dev_attrs, -}; - -/* IOCTL interface */ -#ifdef HAVE_UNLOCKED_IOCTL -static long at91_adc_unlocked_ioctl( - struct file *file, unsigned int cmd, unsigned long arg){ -#else -static int at91_adc_ioctl( - struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg){ -#endif - - long retval = 0; - -#ifdef HAVE_UNLOCKED_IOCTL - lock_kernel(); -#endif - - switch (cmd) { - case ADC_REQUEST: - retval = mux_chan ((int)arg, 1); - break; - - case ADC_READ: - retval = at91_adc_read_chan((int)arg); - break; - - case ADC_FREE: - retval = mux_chan ((int)arg, 0); - break; - - default: - retval = -EINVAL; - } - -#ifdef HAVE_UNLOCKED_IOCTL - unlock_kernel(); -#endif - - return retval; -} - -struct file_operations at91_adc_fops = { - .owner = THIS_MODULE, -#ifdef HAVE_UNLOCKED_IOCTL - .unlocked_ioctl = at91_adc_unlocked_ioctl, -#else - .ioctl = at91_adc_ioctl, -#endif -}; - -static void at91_adc_cdev_teardown(void){ - if(at91_adc_class){ - device_destroy(at91_adc_class, at91_adc_devno); - class_destroy(at91_adc_class); - } - - if(at91_adc_devno){ - unregister_chrdev_region(at91_adc_devno,1); - if(at91_adc_cdev){ cdev_del(at91_adc_cdev); } - } - - at91_adc_devno = 0; - at91_adc_cdev = NULL; - at91_adc_class = NULL; - return; -} - -static int at91_adc_cdev_setup(void){ - - int status; - /* alloc a new device number (major: dynamic, minor: 0) */ - status = alloc_chrdev_region(&at91_adc_devno,0,1,at91_adc_device.name); - - if(status){ - goto err; - } - - /* create a new char device */ - at91_adc_cdev = cdev_alloc(); - if(at91_adc_cdev == NULL){ status=-ENOMEM; goto err; } - at91_adc_cdev->owner = THIS_MODULE; - at91_adc_cdev->ops = &at91_adc_fops; - status = cdev_add(at91_adc_cdev,at91_adc_devno,1); - if(status){ - goto err; - } - - /* register the class */ - at91_adc_class = class_create(THIS_MODULE, DRV_CLASS); - if(IS_ERR(at91_adc_class)){ status=-EFAULT; goto err; } - device_create(at91_adc_class, NULL, at91_adc_devno, NULL, at91_adc_device.name); - printk(KERN_INFO "Major: %u; minor: %u\n", \ - MAJOR(at91_adc_devno), MINOR(at91_adc_devno) \ - ); - - return 0; - -err: - at91_adc_cdev_teardown(); - return status; -} - -/* Module init/exit */ -static int __init at91_adc_init(void){ - - int status; - - at91_adc_clk = clk_get(NULL,"adc_clk"); - clk_enable(at91_adc_clk); - - at91_adc_base = ioremap(AT91SAM9260_BASE_ADC,SZ_256); - if(!at91_adc_base){ - status=-ENODEV; - goto fail_no_iomem_adc; - } - - at91_pioc_base = ioremap(AT91_BASE_SYS + AT91_PIOC,SZ_512); - if(!at91_pioc_base){ - status=-ENODEV; - goto fail_no_iomem_pioc; - } - - status = platform_device_register(&at91_adc_device); - if(status){ - goto fail_no_dev; - } - - status = at91_adc_config(AT91_DEFAULT_CONFIG); - if(status){ - goto fail_no_config; - } - - status = sysfs_create_group( - &(at91_adc_device.dev.kobj), &at91_adc_dev_attr_group - ); - - if(status){ - goto fail_no_sysfs; - } - - status = at91_adc_cdev_setup(); - if(status){ - goto fail_no_cdev; - } - - printk(KERN_INFO "Registered device at91_adc.\n"); - return 0; - -fail_no_cdev: -fail_no_sysfs: - // nothing to undo -fail_no_config: - platform_device_unregister(&at91_adc_device); -fail_no_dev: - iounmap(at91_adc_base); -fail_no_iomem_pioc: - iounmap(at91_pioc_base); -fail_no_iomem_adc: - clk_disable(at91_adc_clk); - clk_put(at91_adc_clk); - return status; -} - -static void __exit at91_adc_exit(void){ - - at91_adc_cdev_teardown(); - platform_device_unregister(&at91_adc_device); - iounmap(at91_adc_base); - iounmap(at91_pioc_base); - - clk_disable(at91_adc_clk); - clk_put(at91_adc_clk); - - printk(KERN_INFO "Unregistered device at91_adc.\n"); -} - -module_init(at91_adc_init); -module_exit(at91_adc_exit); - -MODULE_AUTHOR("Paul Kavan"); -MODULE_AUTHOR("Claudio Mignanti"); -MODULE_AUTHOR("Antonio Galea"); -MODULE_AUTHOR("Stefano Barbato"); -MODULE_DESCRIPTION("ADC Driver for the AT91SAM9G20"); -MODULE_LICENSE("GPL"); |