1 /* 2 * Cirrus Logic CLPS711X CLK driver 3 * 4 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 */ 11 12 #include <linux/clk.h> 13 #include <linux/clk-provider.h> 14 #include <linux/clkdev.h> 15 #include <linux/io.h> 16 #include <linux/ioport.h> 17 #include <linux/of_address.h> 18 #include <linux/slab.h> 19 #include <linux/mfd/syscon/clps711x.h> 20 21 #include <dt-bindings/clock/clps711x-clock.h> 22 23 #define CLPS711X_SYSCON1 (0x0100) 24 #define CLPS711X_SYSCON2 (0x1100) 25 #define CLPS711X_SYSFLG2 (CLPS711X_SYSCON2 + SYSFLG_OFFSET) 26 #define CLPS711X_PLLR (0xa5a8) 27 28 #define CLPS711X_EXT_FREQ (13000000) 29 #define CLPS711X_OSC_FREQ (3686400) 30 31 static const struct clk_div_table spi_div_table[] = { 32 { .val = 0, .div = 32, }, 33 { .val = 1, .div = 8, }, 34 { .val = 2, .div = 2, }, 35 { .val = 3, .div = 1, }, 36 }; 37 38 static const struct clk_div_table timer_div_table[] = { 39 { .val = 0, .div = 256, }, 40 { .val = 1, .div = 1, }, 41 }; 42 43 struct clps711x_clk { 44 struct clk_onecell_data clk_data; 45 spinlock_t lock; 46 struct clk *clks[CLPS711X_CLK_MAX]; 47 }; 48 49 static struct clps711x_clk * __init _clps711x_clk_init(void __iomem *base, 50 u32 fref) 51 { 52 u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi; 53 struct clps711x_clk *clps711x_clk; 54 unsigned i; 55 56 if (!base) 57 return ERR_PTR(-ENOMEM); 58 59 clps711x_clk = kzalloc(sizeof(*clps711x_clk), GFP_KERNEL); 60 if (!clps711x_clk) 61 return ERR_PTR(-ENOMEM); 62 63 spin_lock_init(&clps711x_clk->lock); 64 65 /* Read PLL multiplier value and sanity check */ 66 tmp = readl(base + CLPS711X_PLLR) >> 24; 67 if (((tmp >= 10) && (tmp <= 50)) || !fref) 68 f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2); 69 else 70 f_pll = fref; 71 72 tmp = readl(base + CLPS711X_SYSFLG2); 73 if (tmp & SYSFLG2_CKMODE) { 74 f_cpu = CLPS711X_EXT_FREQ; 75 f_bus = CLPS711X_EXT_FREQ; 76 f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96); 77 f_pll = 0; 78 f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128); 79 } else { 80 f_cpu = f_pll; 81 if (f_cpu > 36864000) 82 f_bus = DIV_ROUND_UP(f_cpu, 2); 83 else 84 f_bus = 36864000 / 2; 85 f_spi = DIV_ROUND_CLOSEST(f_cpu, 576); 86 f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768); 87 } 88 89 if (tmp & SYSFLG2_CKMODE) { 90 if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB) 91 f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26); 92 else 93 f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24); 94 } else 95 f_tim = DIV_ROUND_CLOSEST(f_cpu, 144); 96 97 tmp = readl(base + CLPS711X_SYSCON1); 98 /* Timer1 in free running mode. 99 * Counter will wrap around to 0xffff when it underflows 100 * and will continue to count down. 101 */ 102 tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S); 103 /* Timer2 in prescale mode. 104 * Value writen is automatically re-loaded when 105 * the counter underflows. 106 */ 107 tmp |= SYSCON1_TC2M | SYSCON1_TC2S; 108 writel(tmp, base + CLPS711X_SYSCON1); 109 110 clps711x_clk->clks[CLPS711X_CLK_DUMMY] = 111 clk_register_fixed_rate(NULL, "dummy", NULL, CLK_IS_ROOT, 0); 112 clps711x_clk->clks[CLPS711X_CLK_CPU] = 113 clk_register_fixed_rate(NULL, "cpu", NULL, CLK_IS_ROOT, f_cpu); 114 clps711x_clk->clks[CLPS711X_CLK_BUS] = 115 clk_register_fixed_rate(NULL, "bus", NULL, CLK_IS_ROOT, f_bus); 116 clps711x_clk->clks[CLPS711X_CLK_PLL] = 117 clk_register_fixed_rate(NULL, "pll", NULL, CLK_IS_ROOT, f_pll); 118 clps711x_clk->clks[CLPS711X_CLK_TIMERREF] = 119 clk_register_fixed_rate(NULL, "timer_ref", NULL, CLK_IS_ROOT, 120 f_tim); 121 clps711x_clk->clks[CLPS711X_CLK_TIMER1] = 122 clk_register_divider_table(NULL, "timer1", "timer_ref", 0, 123 base + CLPS711X_SYSCON1, 5, 1, 0, 124 timer_div_table, &clps711x_clk->lock); 125 clps711x_clk->clks[CLPS711X_CLK_TIMER2] = 126 clk_register_divider_table(NULL, "timer2", "timer_ref", 0, 127 base + CLPS711X_SYSCON1, 7, 1, 0, 128 timer_div_table, &clps711x_clk->lock); 129 clps711x_clk->clks[CLPS711X_CLK_PWM] = 130 clk_register_fixed_rate(NULL, "pwm", NULL, CLK_IS_ROOT, f_pwm); 131 clps711x_clk->clks[CLPS711X_CLK_SPIREF] = 132 clk_register_fixed_rate(NULL, "spi_ref", NULL, CLK_IS_ROOT, 133 f_spi); 134 clps711x_clk->clks[CLPS711X_CLK_SPI] = 135 clk_register_divider_table(NULL, "spi", "spi_ref", 0, 136 base + CLPS711X_SYSCON1, 16, 2, 0, 137 spi_div_table, &clps711x_clk->lock); 138 clps711x_clk->clks[CLPS711X_CLK_UART] = 139 clk_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10); 140 clps711x_clk->clks[CLPS711X_CLK_TICK] = 141 clk_register_fixed_rate(NULL, "tick", NULL, CLK_IS_ROOT, 64); 142 143 for (i = 0; i < CLPS711X_CLK_MAX; i++) 144 if (IS_ERR(clps711x_clk->clks[i])) 145 pr_err("clk %i: register failed with %ld\n", 146 i, PTR_ERR(clps711x_clk->clks[i])); 147 148 return clps711x_clk; 149 } 150 151 void __init clps711x_clk_init(void __iomem *base) 152 { 153 struct clps711x_clk *clps711x_clk; 154 155 clps711x_clk = _clps711x_clk_init(base, 73728000); 156 157 BUG_ON(IS_ERR(clps711x_clk)); 158 159 /* Clocksource */ 160 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER1], 161 NULL, "clps711x-timer.0"); 162 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER2], 163 NULL, "clps711x-timer.1"); 164 165 /* Drivers */ 166 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_PWM], 167 NULL, "clps711x-pwm"); 168 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART], 169 NULL, "clps711x-uart.0"); 170 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART], 171 NULL, "clps711x-uart.1"); 172 } 173 174 #ifdef CONFIG_OF 175 static void __init clps711x_clk_init_dt(struct device_node *np) 176 { 177 void __iomem *base = of_iomap(np, 0); 178 struct clps711x_clk *clps711x_clk; 179 u32 fref = 0; 180 181 WARN_ON(of_property_read_u32(np, "startup-frequency", &fref)); 182 183 clps711x_clk = _clps711x_clk_init(base, fref); 184 BUG_ON(IS_ERR(clps711x_clk)); 185 186 clps711x_clk->clk_data.clks = clps711x_clk->clks; 187 clps711x_clk->clk_data.clk_num = CLPS711X_CLK_MAX; 188 of_clk_add_provider(np, of_clk_src_onecell_get, 189 &clps711x_clk->clk_data); 190 } 191 CLK_OF_DECLARE(clps711x, "cirrus,clps711x-clk", clps711x_clk_init_dt); 192 #endif 193