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path: root/drivers/clk/clk-clps711x.c
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-rw-r--r--drivers/clk/clk-clps711x.c192
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