192 lines
5.8 KiB
C
192 lines
5.8 KiB
C
/*
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* Cirrus Logic CLPS711X CLK driver
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*
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* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/clk-provider.h>
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#include <linux/clkdev.h>
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#include <linux/io.h>
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#include <linux/ioport.h>
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#include <linux/of_address.h>
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#include <linux/slab.h>
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#include <linux/mfd/syscon/clps711x.h>
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#include <dt-bindings/clock/clps711x-clock.h>
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#define CLPS711X_SYSCON1 (0x0100)
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#define CLPS711X_SYSCON2 (0x1100)
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#define CLPS711X_SYSFLG2 (CLPS711X_SYSCON2 + SYSFLG_OFFSET)
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#define CLPS711X_PLLR (0xa5a8)
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#define CLPS711X_EXT_FREQ (13000000)
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#define CLPS711X_OSC_FREQ (3686400)
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static const struct clk_div_table spi_div_table[] = {
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{ .val = 0, .div = 32, },
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{ .val = 1, .div = 8, },
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{ .val = 2, .div = 2, },
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{ .val = 3, .div = 1, },
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};
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static const struct clk_div_table timer_div_table[] = {
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{ .val = 0, .div = 256, },
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{ .val = 1, .div = 1, },
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};
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struct clps711x_clk {
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struct clk_onecell_data clk_data;
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spinlock_t lock;
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struct clk *clks[CLPS711X_CLK_MAX];
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};
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static struct clps711x_clk * __init _clps711x_clk_init(void __iomem *base,
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u32 fref)
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{
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u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi;
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struct clps711x_clk *clps711x_clk;
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unsigned i;
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if (!base)
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return ERR_PTR(-ENOMEM);
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clps711x_clk = kzalloc(sizeof(*clps711x_clk), GFP_KERNEL);
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if (!clps711x_clk)
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return ERR_PTR(-ENOMEM);
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spin_lock_init(&clps711x_clk->lock);
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/* Read PLL multiplier value and sanity check */
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tmp = readl(base + CLPS711X_PLLR) >> 24;
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if (((tmp >= 10) && (tmp <= 50)) || !fref)
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f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2);
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else
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f_pll = fref;
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tmp = readl(base + CLPS711X_SYSFLG2);
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if (tmp & SYSFLG2_CKMODE) {
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f_cpu = CLPS711X_EXT_FREQ;
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f_bus = CLPS711X_EXT_FREQ;
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f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96);
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f_pll = 0;
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f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128);
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} else {
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f_cpu = f_pll;
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if (f_cpu > 36864000)
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f_bus = DIV_ROUND_UP(f_cpu, 2);
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else
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f_bus = 36864000 / 2;
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f_spi = DIV_ROUND_CLOSEST(f_cpu, 576);
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f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768);
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}
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if (tmp & SYSFLG2_CKMODE) {
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if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB)
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f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26);
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else
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f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24);
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} else
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f_tim = DIV_ROUND_CLOSEST(f_cpu, 144);
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tmp = readl(base + CLPS711X_SYSCON1);
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/* Timer1 in free running mode.
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* Counter will wrap around to 0xffff when it underflows
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* and will continue to count down.
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*/
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tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S);
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/* Timer2 in prescale mode.
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* Value writen is automatically re-loaded when
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* the counter underflows.
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*/
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tmp |= SYSCON1_TC2M | SYSCON1_TC2S;
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writel(tmp, base + CLPS711X_SYSCON1);
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clps711x_clk->clks[CLPS711X_CLK_DUMMY] =
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clk_register_fixed_rate(NULL, "dummy", NULL, CLK_IS_ROOT, 0);
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clps711x_clk->clks[CLPS711X_CLK_CPU] =
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clk_register_fixed_rate(NULL, "cpu", NULL, CLK_IS_ROOT, f_cpu);
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clps711x_clk->clks[CLPS711X_CLK_BUS] =
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clk_register_fixed_rate(NULL, "bus", NULL, CLK_IS_ROOT, f_bus);
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clps711x_clk->clks[CLPS711X_CLK_PLL] =
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clk_register_fixed_rate(NULL, "pll", NULL, CLK_IS_ROOT, f_pll);
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clps711x_clk->clks[CLPS711X_CLK_TIMERREF] =
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clk_register_fixed_rate(NULL, "timer_ref", NULL, CLK_IS_ROOT,
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f_tim);
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clps711x_clk->clks[CLPS711X_CLK_TIMER1] =
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clk_register_divider_table(NULL, "timer1", "timer_ref", 0,
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base + CLPS711X_SYSCON1, 5, 1, 0,
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timer_div_table, &clps711x_clk->lock);
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clps711x_clk->clks[CLPS711X_CLK_TIMER2] =
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clk_register_divider_table(NULL, "timer2", "timer_ref", 0,
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base + CLPS711X_SYSCON1, 7, 1, 0,
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timer_div_table, &clps711x_clk->lock);
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clps711x_clk->clks[CLPS711X_CLK_PWM] =
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clk_register_fixed_rate(NULL, "pwm", NULL, CLK_IS_ROOT, f_pwm);
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clps711x_clk->clks[CLPS711X_CLK_SPIREF] =
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clk_register_fixed_rate(NULL, "spi_ref", NULL, CLK_IS_ROOT,
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f_spi);
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clps711x_clk->clks[CLPS711X_CLK_SPI] =
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clk_register_divider_table(NULL, "spi", "spi_ref", 0,
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base + CLPS711X_SYSCON1, 16, 2, 0,
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spi_div_table, &clps711x_clk->lock);
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clps711x_clk->clks[CLPS711X_CLK_UART] =
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clk_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10);
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clps711x_clk->clks[CLPS711X_CLK_TICK] =
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clk_register_fixed_rate(NULL, "tick", NULL, CLK_IS_ROOT, 64);
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for (i = 0; i < CLPS711X_CLK_MAX; i++)
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if (IS_ERR(clps711x_clk->clks[i]))
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pr_err("clk %i: register failed with %ld\n",
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i, PTR_ERR(clps711x_clk->clks[i]));
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return clps711x_clk;
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}
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void __init clps711x_clk_init(void __iomem *base)
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{
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struct clps711x_clk *clps711x_clk;
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clps711x_clk = _clps711x_clk_init(base, 73728000);
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BUG_ON(IS_ERR(clps711x_clk));
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/* Clocksource */
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clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER1],
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NULL, "clps711x-timer.0");
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clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER2],
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NULL, "clps711x-timer.1");
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/* Drivers */
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clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_PWM],
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NULL, "clps711x-pwm");
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clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART],
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NULL, "clps711x-uart.0");
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clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART],
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NULL, "clps711x-uart.1");
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}
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#ifdef CONFIG_OF
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static void __init clps711x_clk_init_dt(struct device_node *np)
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{
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void __iomem *base = of_iomap(np, 0);
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struct clps711x_clk *clps711x_clk;
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u32 fref = 0;
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WARN_ON(of_property_read_u32(np, "startup-frequency", &fref));
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clps711x_clk = _clps711x_clk_init(base, fref);
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BUG_ON(IS_ERR(clps711x_clk));
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clps711x_clk->clk_data.clks = clps711x_clk->clks;
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clps711x_clk->clk_data.clk_num = CLPS711X_CLK_MAX;
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of_clk_add_provider(np, of_clk_src_onecell_get,
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&clps711x_clk->clk_data);
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}
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CLK_OF_DECLARE(clps711x, "cirrus,clps711x-clk", clps711x_clk_init_dt);
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#endif
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