linux/drivers/clk/clk-clps711x.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Cirrus Logic CLPS711X CLK driver
   4 *
   5 *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
   6 */
   7
   8#include <linux/clk-provider.h>
   9#include <linux/clkdev.h>
  10#include <linux/io.h>
  11#include <linux/ioport.h>
  12#include <linux/of_address.h>
  13#include <linux/slab.h>
  14#include <linux/mfd/syscon/clps711x.h>
  15
  16#include <dt-bindings/clock/clps711x-clock.h>
  17
  18#define CLPS711X_SYSCON1        (0x0100)
  19#define CLPS711X_SYSCON2        (0x1100)
  20#define CLPS711X_SYSFLG2        (CLPS711X_SYSCON2 + SYSFLG_OFFSET)
  21#define CLPS711X_PLLR           (0xa5a8)
  22
  23#define CLPS711X_EXT_FREQ       (13000000)
  24#define CLPS711X_OSC_FREQ       (3686400)
  25
  26static const struct clk_div_table spi_div_table[] = {
  27        { .val = 0, .div = 32, },
  28        { .val = 1, .div = 8, },
  29        { .val = 2, .div = 2, },
  30        { .val = 3, .div = 1, },
  31};
  32
  33static const struct clk_div_table timer_div_table[] = {
  34        { .val = 0, .div = 256, },
  35        { .val = 1, .div = 1, },
  36};
  37
  38struct clps711x_clk {
  39        spinlock_t                      lock;
  40        struct clk_hw_onecell_data      clk_data;
  41};
  42
  43static void __init clps711x_clk_init_dt(struct device_node *np)
  44{
  45        u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi, fref = 0;
  46        struct clps711x_clk *clps711x_clk;
  47        void __iomem *base;
  48
  49        WARN_ON(of_property_read_u32(np, "startup-frequency", &fref));
  50
  51        base = of_iomap(np, 0);
  52        BUG_ON(!base);
  53
  54        clps711x_clk = kzalloc(struct_size(clps711x_clk, clk_data.hws,
  55                                           CLPS711X_CLK_MAX),
  56                               GFP_KERNEL);
  57        BUG_ON(!clps711x_clk);
  58
  59        spin_lock_init(&clps711x_clk->lock);
  60
  61        /* Read PLL multiplier value and sanity check */
  62        tmp = readl(base + CLPS711X_PLLR) >> 24;
  63        if (((tmp >= 10) && (tmp <= 50)) || !fref)
  64                f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2);
  65        else
  66                f_pll = fref;
  67
  68        tmp = readl(base + CLPS711X_SYSFLG2);
  69        if (tmp & SYSFLG2_CKMODE) {
  70                f_cpu = CLPS711X_EXT_FREQ;
  71                f_bus = CLPS711X_EXT_FREQ;
  72                f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96);
  73                f_pll = 0;
  74                f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128);
  75        } else {
  76                f_cpu = f_pll;
  77                if (f_cpu > 36864000)
  78                        f_bus = DIV_ROUND_UP(f_cpu, 2);
  79                else
  80                        f_bus = 36864000 / 2;
  81                f_spi = DIV_ROUND_CLOSEST(f_cpu, 576);
  82                f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768);
  83        }
  84
  85        if (tmp & SYSFLG2_CKMODE) {
  86                if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB)
  87                        f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26);
  88                else
  89                        f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24);
  90        } else
  91                f_tim = DIV_ROUND_CLOSEST(f_cpu, 144);
  92
  93        tmp = readl(base + CLPS711X_SYSCON1);
  94        /* Timer1 in free running mode.
  95         * Counter will wrap around to 0xffff when it underflows
  96         * and will continue to count down.
  97         */
  98        tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S);
  99        /* Timer2 in prescale mode.
 100         * Value writen is automatically re-loaded when
 101         * the counter underflows.
 102         */
 103        tmp |= SYSCON1_TC2M | SYSCON1_TC2S;
 104        writel(tmp, base + CLPS711X_SYSCON1);
 105
 106        clps711x_clk->clk_data.hws[CLPS711X_CLK_DUMMY] =
 107                clk_hw_register_fixed_rate(NULL, "dummy", NULL, 0, 0);
 108        clps711x_clk->clk_data.hws[CLPS711X_CLK_CPU] =
 109                clk_hw_register_fixed_rate(NULL, "cpu", NULL, 0, f_cpu);
 110        clps711x_clk->clk_data.hws[CLPS711X_CLK_BUS] =
 111                clk_hw_register_fixed_rate(NULL, "bus", NULL, 0, f_bus);
 112        clps711x_clk->clk_data.hws[CLPS711X_CLK_PLL] =
 113                clk_hw_register_fixed_rate(NULL, "pll", NULL, 0, f_pll);
 114        clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMERREF] =
 115                clk_hw_register_fixed_rate(NULL, "timer_ref", NULL, 0, f_tim);
 116        clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER1] =
 117                clk_hw_register_divider_table(NULL, "timer1", "timer_ref", 0,
 118                                           base + CLPS711X_SYSCON1, 5, 1, 0,
 119                                           timer_div_table, &clps711x_clk->lock);
 120        clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER2] =
 121                clk_hw_register_divider_table(NULL, "timer2", "timer_ref", 0,
 122                                           base + CLPS711X_SYSCON1, 7, 1, 0,
 123                                           timer_div_table, &clps711x_clk->lock);
 124        clps711x_clk->clk_data.hws[CLPS711X_CLK_PWM] =
 125                clk_hw_register_fixed_rate(NULL, "pwm", NULL, 0, f_pwm);
 126        clps711x_clk->clk_data.hws[CLPS711X_CLK_SPIREF] =
 127                clk_hw_register_fixed_rate(NULL, "spi_ref", NULL, 0, f_spi);
 128        clps711x_clk->clk_data.hws[CLPS711X_CLK_SPI] =
 129                clk_hw_register_divider_table(NULL, "spi", "spi_ref", 0,
 130                                           base + CLPS711X_SYSCON1, 16, 2, 0,
 131                                           spi_div_table, &clps711x_clk->lock);
 132        clps711x_clk->clk_data.hws[CLPS711X_CLK_UART] =
 133                clk_hw_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10);
 134        clps711x_clk->clk_data.hws[CLPS711X_CLK_TICK] =
 135                clk_hw_register_fixed_rate(NULL, "tick", NULL, 0, 64);
 136        for (tmp = 0; tmp < CLPS711X_CLK_MAX; tmp++)
 137                if (IS_ERR(clps711x_clk->clk_data.hws[tmp]))
 138                        pr_err("clk %i: register failed with %ld\n",
 139                               tmp, PTR_ERR(clps711x_clk->clk_data.hws[tmp]));
 140
 141        clps711x_clk->clk_data.num = CLPS711X_CLK_MAX;
 142        of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
 143                               &clps711x_clk->clk_data);
 144}
 145CLK_OF_DECLARE(clps711x, "cirrus,ep7209-clk", clps711x_clk_init_dt);
 146