1 /* 2 * (C) Copyright 2007 3 * Sascha Hauer, Pengutronix 4 * 5 * (C) Copyright 2009 Freescale Semiconductor, Inc. 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 #include <common.h> 11 #include <asm/io.h> 12 #include <div64.h> 13 #include <asm/arch/imx-regs.h> 14 #include <asm/arch/clock.h> 15 #include <asm/arch/sys_proto.h> 16 17 /* General purpose timers registers */ 18 struct mxc_gpt { 19 unsigned int control; 20 unsigned int prescaler; 21 unsigned int status; 22 unsigned int nouse[6]; 23 unsigned int counter; 24 }; 25 26 static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR; 27 28 /* General purpose timers bitfields */ 29 #define GPTCR_SWR (1 << 15) /* Software reset */ 30 #define GPTCR_24MEN (1 << 10) /* Enable 24MHz clock input */ 31 #define GPTCR_FRR (1 << 9) /* Freerun / restart */ 32 #define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source 32khz */ 33 #define GPTCR_CLKSOURCE_OSC (5 << 6) /* Clock source OSC */ 34 #define GPTCR_CLKSOURCE_PRE (1 << 6) /* Clock source PRECLK */ 35 #define GPTCR_CLKSOURCE_MASK (0x7 << 6) 36 #define GPTCR_TEN 1 /* Timer enable */ 37 38 #define GPTPR_PRESCALER24M_SHIFT 12 39 #define GPTPR_PRESCALER24M_MASK (0xF << GPTPR_PRESCALER24M_SHIFT) 40 41 DECLARE_GLOBAL_DATA_PTR; 42 43 static inline int gpt_has_clk_source_osc(void) 44 { 45 #if defined(CONFIG_MX6) 46 if (((is_mx6dq()) && (soc_rev() > CHIP_REV_1_0)) || 47 is_mx6dqp() || is_mx6sdl() || is_mx6sx() || is_mx6ul() || 48 is_mx6ull() || is_mx6sll()) 49 return 1; 50 51 return 0; 52 #else 53 return 0; 54 #endif 55 } 56 57 static inline ulong gpt_get_clk(void) 58 { 59 #ifdef CONFIG_MXC_GPT_HCLK 60 if (gpt_has_clk_source_osc()) 61 return MXC_HCLK >> 3; 62 else 63 return mxc_get_clock(MXC_IPG_PERCLK); 64 #else 65 return MXC_CLK32; 66 #endif 67 } 68 69 int timer_init(void) 70 { 71 int i; 72 73 /* setup GP Timer 1 */ 74 __raw_writel(GPTCR_SWR, &cur_gpt->control); 75 76 /* We have no udelay by now */ 77 for (i = 0; i < 100; i++) 78 __raw_writel(0, &cur_gpt->control); 79 80 i = __raw_readl(&cur_gpt->control); 81 i &= ~GPTCR_CLKSOURCE_MASK; 82 83 #ifdef CONFIG_MXC_GPT_HCLK 84 if (gpt_has_clk_source_osc()) { 85 i |= GPTCR_CLKSOURCE_OSC | GPTCR_TEN; 86 87 /* 88 * For DL/S, SX, UL, ULL, SLL set 24Mhz OSC 89 * Enable bit and prescaler 90 */ 91 if (is_mx6sdl() || is_mx6sx() || is_mx6ul() || is_mx6ull() || 92 is_mx6sll()) { 93 i |= GPTCR_24MEN; 94 95 /* Produce 3Mhz clock */ 96 __raw_writel((7 << GPTPR_PRESCALER24M_SHIFT), 97 &cur_gpt->prescaler); 98 } 99 } else { 100 i |= GPTCR_CLKSOURCE_PRE | GPTCR_TEN; 101 } 102 #else 103 __raw_writel(0, &cur_gpt->prescaler); /* 32Khz */ 104 i |= GPTCR_CLKSOURCE_32 | GPTCR_TEN; 105 #endif 106 __raw_writel(i, &cur_gpt->control); 107 108 return 0; 109 } 110 111 unsigned long timer_read_counter(void) 112 { 113 return __raw_readl(&cur_gpt->counter); /* current tick value */ 114 } 115 116 /* 117 * This function is derived from PowerPC code (timebase clock frequency). 118 * On ARM it returns the number of timer ticks per second. 119 */ 120 ulong get_tbclk(void) 121 { 122 return gpt_get_clk(); 123 } 124 125 /* 126 * This function is intended for SHORT delays only. 127 * It will overflow at around 10 seconds @ 400MHz, 128 * or 20 seconds @ 200MHz. 129 */ 130 unsigned long usec2ticks(unsigned long _usec) 131 { 132 unsigned long long usec = _usec; 133 134 usec *= get_tbclk(); 135 usec += 999999; 136 do_div(usec, 1000000); 137 138 return usec; 139 } 140