1 /* 2 * Cirrus Logic EP93xx PLL support. 3 * 4 * Copyright (C) 2009 Matthias Kaehlcke <matthias@kaehlcke.net> 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #include <common.h> 10 #include <asm/arch/ep93xx.h> 11 #include <asm/io.h> 12 #include <div64.h> 13 14 /* 15 * CONFIG_SYS_CLK_FREQ should be defined as the input frequency of the PLL. 16 * 17 * get_FCLK(), get_HCLK(), get_PCLK() and get_UCLK() return the clock of 18 * the specified bus in HZ. 19 */ 20 21 /* 22 * return the PLL output frequency 23 * 24 * PLL rate = CONFIG_SYS_CLK_FREQ * (X1FBD + 1) * (X2FBD + 1) 25 * / (X2IPD + 1) / 2^PS 26 */ 27 static ulong get_PLLCLK(uint32_t *pllreg) 28 { 29 uint8_t i; 30 const uint32_t clkset = readl(pllreg); 31 uint64_t rate = CONFIG_SYS_CLK_FREQ; 32 rate *= ((clkset >> SYSCON_CLKSET_PLL_X1FBD1_SHIFT) & 0x1f) + 1; 33 rate *= ((clkset >> SYSCON_CLKSET_PLL_X2FBD2_SHIFT) & 0x3f) + 1; 34 do_div(rate, (clkset & 0x1f) + 1); /* X2IPD */ 35 for (i = 0; i < ((clkset >> SYSCON_CLKSET_PLL_PS_SHIFT) & 3); i++) 36 rate >>= 1; 37 38 return (ulong)rate; 39 } 40 41 /* return FCLK frequency */ 42 ulong get_FCLK() 43 { 44 const uint8_t fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 }; 45 struct syscon_regs *syscon = (struct syscon_regs *)SYSCON_BASE; 46 47 const uint32_t clkset1 = readl(&syscon->clkset1); 48 const uint8_t fclk_div = 49 fclk_divisors[(clkset1 >> SYSCON_CLKSET1_FCLK_DIV_SHIFT) & 7]; 50 const ulong fclk_rate = get_PLLCLK(&syscon->clkset1) / fclk_div; 51 52 return fclk_rate; 53 } 54 55 /* return HCLK frequency */ 56 ulong get_HCLK(void) 57 { 58 const uint8_t hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 }; 59 struct syscon_regs *syscon = (struct syscon_regs *)SYSCON_BASE; 60 61 const uint32_t clkset1 = readl(&syscon->clkset1); 62 const uint8_t hclk_div = 63 hclk_divisors[(clkset1 >> SYSCON_CLKSET1_HCLK_DIV_SHIFT) & 7]; 64 const ulong hclk_rate = get_PLLCLK(&syscon->clkset1) / hclk_div; 65 66 return hclk_rate; 67 } 68 69 /* return PCLK frequency */ 70 ulong get_PCLK(void) 71 { 72 const uint8_t pclk_divisors[] = { 1, 2, 4, 8 }; 73 struct syscon_regs *syscon = (struct syscon_regs *)SYSCON_BASE; 74 75 const uint32_t clkset1 = readl(&syscon->clkset1); 76 const uint8_t pclk_div = 77 pclk_divisors[(clkset1 >> SYSCON_CLKSET1_PCLK_DIV_SHIFT) & 3]; 78 const ulong pclk_rate = get_HCLK() / pclk_div; 79 80 return pclk_rate; 81 } 82 83 /* return UCLK frequency */ 84 ulong get_UCLK(void) 85 { 86 struct syscon_regs *syscon = (struct syscon_regs *)SYSCON_BASE; 87 ulong uclk_rate; 88 89 const uint32_t value = readl(&syscon->pwrcnt); 90 if (value & SYSCON_PWRCNT_UART_BAUD) 91 uclk_rate = CONFIG_SYS_CLK_FREQ; 92 else 93 uclk_rate = CONFIG_SYS_CLK_FREQ / 2; 94 95 return uclk_rate; 96 } 97