diff options
Diffstat (limited to 'drivers/clk/clk-clps711x.c')
| -rw-r--r-- | drivers/clk/clk-clps711x.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/clk/clk-clps711x.c b/drivers/clk/clk-clps711x.c new file mode 100644 index 000000000000..715eec1a9902 --- /dev/null +++ b/drivers/clk/clk-clps711x.c @@ -0,0 +1,192 @@ +/* + * Cirrus Logic CLPS711X CLK driver + * + * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/of_address.h> +#include <linux/slab.h> +#include <linux/mfd/syscon/clps711x.h> + +#include <dt-bindings/clock/clps711x-clock.h> + +#define CLPS711X_SYSCON1 (0x0100) +#define CLPS711X_SYSCON2 (0x1100) +#define CLPS711X_SYSFLG2 (CLPS711X_SYSCON2 + SYSFLG_OFFSET) +#define CLPS711X_PLLR (0xa5a8) + +#define CLPS711X_EXT_FREQ (13000000) +#define CLPS711X_OSC_FREQ (3686400) + +static const struct clk_div_table spi_div_table[] = { + { .val = 0, .div = 32, }, + { .val = 1, .div = 8, }, + { .val = 2, .div = 2, }, + { .val = 3, .div = 1, }, +}; + +static const struct clk_div_table timer_div_table[] = { + { .val = 0, .div = 256, }, + { .val = 1, .div = 1, }, +}; + +struct clps711x_clk { + struct clk_onecell_data clk_data; + spinlock_t lock; + struct clk *clks[CLPS711X_CLK_MAX]; +}; + +static struct clps711x_clk * __init _clps711x_clk_init(void __iomem *base, + u32 fref) +{ + u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi; + struct clps711x_clk *clps711x_clk; + unsigned i; + + if (!base) + return ERR_PTR(-ENOMEM); + + clps711x_clk = kzalloc(sizeof(*clps711x_clk), GFP_KERNEL); + if (!clps711x_clk) + return ERR_PTR(-ENOMEM); + + spin_lock_init(&clps711x_clk->lock); + + /* Read PLL multiplier value and sanity check */ + tmp = readl(base + CLPS711X_PLLR) >> 24; + if (((tmp >= 10) && (tmp <= 50)) || !fref) + f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2); + else + f_pll = fref; + + tmp = readl(base + CLPS711X_SYSFLG2); + if (tmp & SYSFLG2_CKMODE) { + f_cpu = CLPS711X_EXT_FREQ; + f_bus = CLPS711X_EXT_FREQ; + f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96); + f_pll = 0; + f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128); + } else { + f_cpu = f_pll; + if (f_cpu > 36864000) + f_bus = DIV_ROUND_UP(f_cpu, 2); + else + f_bus = 36864000 / 2; + f_spi = DIV_ROUND_CLOSEST(f_cpu, 576); + f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768); + } + + if (tmp & SYSFLG2_CKMODE) { + if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB) + f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26); + else + f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24); + } else + f_tim = DIV_ROUND_CLOSEST(f_cpu, 144); + + tmp = readl(base + CLPS711X_SYSCON1); + /* Timer1 in free running mode. + * Counter will wrap around to 0xffff when it underflows + * and will continue to count down. + */ + tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S); + /* Timer2 in prescale mode. + * Value writen is automatically re-loaded when + * the counter underflows. + */ + tmp |= SYSCON1_TC2M | SYSCON1_TC2S; + writel(tmp, base + CLPS711X_SYSCON1); + + clps711x_clk->clks[CLPS711X_CLK_DUMMY] = + clk_register_fixed_rate(NULL, "dummy", NULL, CLK_IS_ROOT, 0); + clps711x_clk->clks[CLPS711X_CLK_CPU] = + clk_register_fixed_rate(NULL, "cpu", NULL, CLK_IS_ROOT, f_cpu); + clps711x_clk->clks[CLPS711X_CLK_BUS] = + clk_register_fixed_rate(NULL, "bus", NULL, CLK_IS_ROOT, f_bus); + clps711x_clk->clks[CLPS711X_CLK_PLL] = + clk_register_fixed_rate(NULL, "pll", NULL, CLK_IS_ROOT, f_pll); + clps711x_clk->clks[CLPS711X_CLK_TIMERREF] = + clk_register_fixed_rate(NULL, "timer_ref", NULL, CLK_IS_ROOT, + f_tim); + clps711x_clk->clks[CLPS711X_CLK_TIMER1] = + clk_register_divider_table(NULL, "timer1", "timer_ref", 0, + base + CLPS711X_SYSCON1, 5, 1, 0, + timer_div_table, &clps711x_clk->lock); + clps711x_clk->clks[CLPS711X_CLK_TIMER2] = + clk_register_divider_table(NULL, "timer2", "timer_ref", 0, + base + CLPS711X_SYSCON1, 7, 1, 0, + timer_div_table, &clps711x_clk->lock); + clps711x_clk->clks[CLPS711X_CLK_PWM] = + clk_register_fixed_rate(NULL, "pwm", NULL, CLK_IS_ROOT, f_pwm); + clps711x_clk->clks[CLPS711X_CLK_SPIREF] = + clk_register_fixed_rate(NULL, "spi_ref", NULL, CLK_IS_ROOT, + f_spi); + clps711x_clk->clks[CLPS711X_CLK_SPI] = + clk_register_divider_table(NULL, "spi", "spi_ref", 0, + base + CLPS711X_SYSCON1, 16, 2, 0, + spi_div_table, &clps711x_clk->lock); + clps711x_clk->clks[CLPS711X_CLK_UART] = + clk_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10); + clps711x_clk->clks[CLPS711X_CLK_TICK] = + clk_register_fixed_rate(NULL, "tick", NULL, CLK_IS_ROOT, 64); + + for (i = 0; i < CLPS711X_CLK_MAX; i++) + if (IS_ERR(clps711x_clk->clks[i])) + pr_err("clk %i: register failed with %ld\n", + i, PTR_ERR(clps711x_clk->clks[i])); + + return clps711x_clk; +} + +void __init clps711x_clk_init(void __iomem *base) +{ + struct clps711x_clk *clps711x_clk; + + clps711x_clk = _clps711x_clk_init(base, 73728000); + + BUG_ON(IS_ERR(clps711x_clk)); + + /* Clocksource */ + clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER1], + NULL, "clps711x-timer.0"); + clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER2], + NULL, "clps711x-timer.1"); + + /* Drivers */ + clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_PWM], + NULL, "clps711x-pwm"); + clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART], + NULL, "clps711x-uart.0"); + clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART], + NULL, "clps711x-uart.1"); +} + +#ifdef CONFIG_OF +static void __init clps711x_clk_init_dt(struct device_node *np) +{ + void __iomem *base = of_iomap(np, 0); + struct clps711x_clk *clps711x_clk; + u32 fref = 0; + + WARN_ON(of_property_read_u32(np, "startup-frequency", &fref)); + + clps711x_clk = _clps711x_clk_init(base, fref); + BUG_ON(IS_ERR(clps711x_clk)); + + clps711x_clk->clk_data.clks = clps711x_clk->clks; + clps711x_clk->clk_data.clk_num = CLPS711X_CLK_MAX; + of_clk_add_provider(np, of_clk_src_onecell_get, + &clps711x_clk->clk_data); +} +CLK_OF_DECLARE(clps711x, "cirrus,clps711x-clk", clps711x_clk_init_dt); +#endif |