/drivers/misc/atmel_tclib.c
C | 162 lines | 109 code | 28 blank | 25 comment | 15 complexity | c94c1af8caab40b1afffc444dfd526e2 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
1#include <linux/atmel_tc.h> 2#include <linux/clk.h> 3#include <linux/err.h> 4#include <linux/init.h> 5#include <linux/io.h> 6#include <linux/ioport.h> 7#include <linux/kernel.h> 8#include <linux/platform_device.h> 9#include <linux/slab.h> 10 11/* Number of bytes to reserve for the iomem resource */ 12#define ATMEL_TC_IOMEM_SIZE 256 13 14 15/* 16 * This is a thin library to solve the problem of how to portably allocate 17 * one of the TC blocks. For simplicity, it doesn't currently expect to 18 * share individual timers between different drivers. 19 */ 20 21#if defined(CONFIG_AVR32) 22/* AVR32 has these divide PBB */ 23const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, }; 24EXPORT_SYMBOL(atmel_tc_divisors); 25 26#elif defined(CONFIG_ARCH_AT91) 27/* AT91 has these divide MCK */ 28const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, }; 29EXPORT_SYMBOL(atmel_tc_divisors); 30 31#endif 32 33static DEFINE_SPINLOCK(tc_list_lock); 34static LIST_HEAD(tc_list); 35 36/** 37 * atmel_tc_alloc - allocate a specified TC block 38 * @block: which block to allocate 39 * @name: name to be associated with the iomem resource 40 * 41 * Caller allocates a block. If it is available, a pointer to a 42 * pre-initialized struct atmel_tc is returned. The caller can access 43 * the registers directly through the "regs" field. 44 */ 45struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name) 46{ 47 struct atmel_tc *tc; 48 struct platform_device *pdev = NULL; 49 struct resource *r; 50 51 spin_lock(&tc_list_lock); 52 list_for_each_entry(tc, &tc_list, node) { 53 if (tc->pdev->id == block) { 54 pdev = tc->pdev; 55 break; 56 } 57 } 58 59 if (!pdev || tc->iomem) 60 goto fail; 61 62 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 63 r = request_mem_region(r->start, ATMEL_TC_IOMEM_SIZE, name); 64 if (!r) 65 goto fail; 66 67 tc->regs = ioremap(r->start, ATMEL_TC_IOMEM_SIZE); 68 if (!tc->regs) 69 goto fail_ioremap; 70 71 tc->iomem = r; 72 73out: 74 spin_unlock(&tc_list_lock); 75 return tc; 76 77fail_ioremap: 78 release_mem_region(r->start, ATMEL_TC_IOMEM_SIZE); 79fail: 80 tc = NULL; 81 goto out; 82} 83EXPORT_SYMBOL_GPL(atmel_tc_alloc); 84 85/** 86 * atmel_tc_free - release a specified TC block 87 * @tc: Timer/counter block that was returned by atmel_tc_alloc() 88 * 89 * This reverses the effect of atmel_tc_alloc(), unmapping the I/O 90 * registers, invalidating the resource returned by that routine and 91 * making the TC available to other drivers. 92 */ 93void atmel_tc_free(struct atmel_tc *tc) 94{ 95 spin_lock(&tc_list_lock); 96 if (tc->regs) { 97 iounmap(tc->regs); 98 release_mem_region(tc->iomem->start, ATMEL_TC_IOMEM_SIZE); 99 tc->regs = NULL; 100 tc->iomem = NULL; 101 } 102 spin_unlock(&tc_list_lock); 103} 104EXPORT_SYMBOL_GPL(atmel_tc_free); 105 106static int __init tc_probe(struct platform_device *pdev) 107{ 108 struct atmel_tc *tc; 109 struct clk *clk; 110 int irq; 111 112 if (!platform_get_resource(pdev, IORESOURCE_MEM, 0)) 113 return -EINVAL; 114 115 irq = platform_get_irq(pdev, 0); 116 if (irq < 0) 117 return -EINVAL; 118 119 tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL); 120 if (!tc) 121 return -ENOMEM; 122 123 tc->pdev = pdev; 124 125 clk = clk_get(&pdev->dev, "t0_clk"); 126 if (IS_ERR(clk)) { 127 kfree(tc); 128 return -EINVAL; 129 } 130 131 tc->clk[0] = clk; 132 tc->clk[1] = clk_get(&pdev->dev, "t1_clk"); 133 if (IS_ERR(tc->clk[1])) 134 tc->clk[1] = clk; 135 tc->clk[2] = clk_get(&pdev->dev, "t2_clk"); 136 if (IS_ERR(tc->clk[2])) 137 tc->clk[2] = clk; 138 139 tc->irq[0] = irq; 140 tc->irq[1] = platform_get_irq(pdev, 1); 141 if (tc->irq[1] < 0) 142 tc->irq[1] = irq; 143 tc->irq[2] = platform_get_irq(pdev, 2); 144 if (tc->irq[2] < 0) 145 tc->irq[2] = irq; 146 147 spin_lock(&tc_list_lock); 148 list_add_tail(&tc->node, &tc_list); 149 spin_unlock(&tc_list_lock); 150 151 return 0; 152} 153 154static struct platform_driver tc_driver = { 155 .driver.name = "atmel_tcb", 156}; 157 158static int __init tc_init(void) 159{ 160 return platform_driver_probe(&tc_driver, tc_probe); 161} 162arch_initcall(tc_init);