ARM: SAMSUNG: Move pwm-clock code into plat-samsung

Move the code for the pwm-clock into plat-samsung, as it is common to
all Samsung SoCs.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 455 insertions, 0 deletions

diff --git a/arch/arm/plat-samsung/pwm-clock.c b/arch/arm/plat-samsung/pwm-clock.c
new file mode 100644
index 000000000000..46c9381e083b
--- /dev/null
+++ b/arch/arm/plat-samsung/pwm-clock.c
@@ -0,0 +1,455 @@
+/* linux/arch/arm/plat-s3c24xx/pwm-clock.c
+ *
+ * Copyright (c) 2007 Simtec Electronics
+ * Copyright (c) 2007, 2008 Ben Dooks
+ *      Ben Dooks <ben-linux@fluff.org>
+ *
+ * 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.
+*/
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/log2.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <mach/hardware.h>
+#include <mach/map.h>
+#include <asm/irq.h>
+
+#include <plat/clock.h>
+#include <plat/cpu.h>
+
+#include <plat/regs-timer.h>
+#include <mach/pwm-clock.h>
+
+/* Each of the timers 0 through 5 go through the following
+ * clock tree, with the inputs depending on the timers.
+ *
+ * pclk ---- [ prescaler 0 ] -+---> timer 0
+ *                            +---> timer 1
+ *
+ * pclk ---- [ prescaler 1 ] -+---> timer 2
+ *                            +---> timer 3
+ *                            \---> timer 4
+ *
+ * Which are fed into the timers as so:
+ *
+ * prescaled 0 ---- [ div 2,4,8,16 ] ---\
+ *                                     [mux] -> timer 0
+ * tclk 0 ------------------------------/
+ *
+ * prescaled 0 ---- [ div 2,4,8,16 ] ---\
+ *                                     [mux] -> timer 1
+ * tclk 0 ------------------------------/
+ *
+ *
+ * prescaled 1 ---- [ div 2,4,8,16 ] ---\
+ *                                     [mux] -> timer 2
+ * tclk 1 ------------------------------/
+ *
+ * prescaled 1 ---- [ div 2,4,8,16 ] ---\
+ *                                     [mux] -> timer 3
+ * tclk 1 ------------------------------/
+ *
+ * prescaled 1 ---- [ div 2,4,8, 16 ] --\
+ *                                     [mux] -> timer 4
+ * tclk 1 ------------------------------/
+ *
+ * Since the mux and the divider are tied together in the
+ * same register space, it is impossible to set the parent
+ * and the rate at the same time. To avoid this, we add an
+ * intermediate 'prescaled-and-divided' clock to select
+ * as the parent for the timer input clock called tdiv.
+ *
+ * prescaled clk --> pwm-tdiv ---\
+ *                             [ mux ] --> timer X
+ * tclk -------------------------/
+*/
+
+static struct clk clk_timer_scaler[];
+
+static unsigned long clk_pwm_scaler_get_rate(struct clk *clk)
+{
+        unsigned long tcfg0 = __raw_readl(S3C2410_TCFG0);
+
+        if (clk == &clk_timer_scaler[1]) {
+                tcfg0 &= S3C2410_TCFG_PRESCALER1_MASK;
+                tcfg0 >>= S3C2410_TCFG_PRESCALER1_SHIFT;
+        } else {
+                tcfg0 &= S3C2410_TCFG_PRESCALER0_MASK;
+        }
+
+        return clk_get_rate(clk->parent) / (tcfg0 + 1);
+}
+
+static unsigned long clk_pwm_scaler_round_rate(struct clk *clk,
+                                               unsigned long rate)
+{
+        unsigned long parent_rate = clk_get_rate(clk->parent);
+        unsigned long divisor = parent_rate / rate;
+
+        if (divisor > 256)
+                divisor = 256;
+        else if (divisor < 2)
+                divisor = 2;
+
+        return parent_rate / divisor;
+}
+
+static int clk_pwm_scaler_set_rate(struct clk *clk, unsigned long rate)
+{
+        unsigned long round = clk_pwm_scaler_round_rate(clk, rate);
+        unsigned long tcfg0;
+        unsigned long divisor;
+        unsigned long flags;
+
+        divisor = clk_get_rate(clk->parent) / round;
+        divisor--;
+
+        local_irq_save(flags);
+        tcfg0 = __raw_readl(S3C2410_TCFG0);
+
+        if (clk == &clk_timer_scaler[1]) {
+                tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK;
+                tcfg0 |= divisor << S3C2410_TCFG_PRESCALER1_SHIFT;
+        } else {
+                tcfg0 &= ~S3C2410_TCFG_PRESCALER0_MASK;
+                tcfg0 |= divisor;
+        }
+
+        __raw_writel(tcfg0, S3C2410_TCFG0);
+        local_irq_restore(flags);
+
+        return 0;
+}
+
+static struct clk_ops clk_pwm_scaler_ops = {
+        .get_rate       = clk_pwm_scaler_get_rate,
+        .set_rate       = clk_pwm_scaler_set_rate,
+        .round_rate     = clk_pwm_scaler_round_rate,
+};
+
+static struct clk clk_timer_scaler[] = {
+        [0]     = {
+                .name           = "pwm-scaler0",
+                .id             = -1,
+                .ops            = &clk_pwm_scaler_ops,
+        },
+        [1]     = {
+                .name           = "pwm-scaler1",
+                .id             = -1,
+                .ops            = &clk_pwm_scaler_ops,
+        },
+};
+
+static struct clk clk_timer_tclk[] = {
+        [0]     = {
+                .name           = "pwm-tclk0",
+                .id             = -1,
+        },
+        [1]     = {
+                .name           = "pwm-tclk1",
+                .id             = -1,
+        },
+};
+
+struct pwm_tdiv_clk {
+        struct clk      clk;
+        unsigned int    divisor;
+};
+
+static inline struct pwm_tdiv_clk *to_tdiv(struct clk *clk)
+{
+        return container_of(clk, struct pwm_tdiv_clk, clk);
+}
+
+static unsigned long clk_pwm_tdiv_get_rate(struct clk *clk)
+{
+        unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+        unsigned int divisor;
+
+        tcfg1 >>= S3C2410_TCFG1_SHIFT(clk->id);
+        tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+        if (pwm_cfg_src_is_tclk(tcfg1))
+                divisor = to_tdiv(clk)->divisor;
+        else
+                divisor = tcfg_to_divisor(tcfg1);
+
+        return clk_get_rate(clk->parent) / divisor;
+}
+
+static unsigned long clk_pwm_tdiv_round_rate(struct clk *clk,
+                                             unsigned long rate)
+{
+        unsigned long parent_rate;
+        unsigned long divisor;
+
+        parent_rate = clk_get_rate(clk->parent);
+        divisor = parent_rate / rate;
+
+        if (divisor <= 1 && pwm_tdiv_has_div1())
+                divisor = 1;
+        else if (divisor <= 2)
+                divisor = 2;
+        else if (divisor <= 4)
+                divisor = 4;
+        else if (divisor <= 8)
+                divisor = 8;
+        else
+                divisor = 16;
+
+        return parent_rate / divisor;
+}
+
+static unsigned long clk_pwm_tdiv_bits(struct pwm_tdiv_clk *divclk)
+{
+        return pwm_tdiv_div_bits(divclk->divisor);
+}
+
+static void clk_pwm_tdiv_update(struct pwm_tdiv_clk *divclk)
+{
+        unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+        unsigned long bits = clk_pwm_tdiv_bits(divclk);
+        unsigned long flags;
+        unsigned long shift =  S3C2410_TCFG1_SHIFT(divclk->clk.id);
+
+        local_irq_save(flags);
+
+        tcfg1 = __raw_readl(S3C2410_TCFG1);
+        tcfg1 &= ~(S3C2410_TCFG1_MUX_MASK << shift);
+        tcfg1 |= bits << shift;
+        __raw_writel(tcfg1, S3C2410_TCFG1);
+
+        local_irq_restore(flags);
+}
+
+static int clk_pwm_tdiv_set_rate(struct clk *clk, unsigned long rate)
+{
+        struct pwm_tdiv_clk *divclk = to_tdiv(clk);
+        unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+        unsigned long parent_rate = clk_get_rate(clk->parent);
+        unsigned long divisor;
+
+        tcfg1 >>= S3C2410_TCFG1_SHIFT(clk->id);
+        tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+        rate = clk_round_rate(clk, rate);
+        divisor = parent_rate / rate;
+
+        if (divisor > 16)
+                return -EINVAL;
+
+        divclk->divisor = divisor;
+
+        /* Update the current MUX settings if we are currently
+         * selected as the clock source for this clock. */
+
+        if (!pwm_cfg_src_is_tclk(tcfg1))
+                clk_pwm_tdiv_update(divclk);
+
+        return 0;
+}
+
+static struct clk_ops clk_tdiv_ops = {
+        .get_rate       = clk_pwm_tdiv_get_rate,
+        .set_rate       = clk_pwm_tdiv_set_rate,
+        .round_rate     = clk_pwm_tdiv_round_rate,
+};
+
+static struct pwm_tdiv_clk clk_timer_tdiv[] = {
+        [0]     = {
+                .clk    = {
+                        .name   = "pwm-tdiv",
+                        .ops    = &clk_tdiv_ops,
+                        .parent = &clk_timer_scaler[0],
+                },
+        },
+        [1]     = {
+                .clk    = {
+                        .name   = "pwm-tdiv",
+                        .ops    = &clk_tdiv_ops,
+                        .parent = &clk_timer_scaler[0],
+                }
+        },
+        [2]     = {
+                .clk    = {
+                        .name   = "pwm-tdiv",
+                        .ops    = &clk_tdiv_ops,
+                        .parent = &clk_timer_scaler[1],
+                },
+        },
+        [3]     = {
+                .clk    = {
+                        .name   = "pwm-tdiv",
+                        .ops    = &clk_tdiv_ops,
+                        .parent = &clk_timer_scaler[1],
+                },
+        },
+        [4]     = {
+                .clk    = {
+                        .name   = "pwm-tdiv",
+                        .ops    = &clk_tdiv_ops,
+                        .parent = &clk_timer_scaler[1],
+                },
+        },
+};
+
+static int __init clk_pwm_tdiv_register(unsigned int id)
+{
+        struct pwm_tdiv_clk *divclk = &clk_timer_tdiv[id];
+        unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+
+        tcfg1 >>= S3C2410_TCFG1_SHIFT(id);
+        tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+        divclk->clk.id = id;
+        divclk->divisor = tcfg_to_divisor(tcfg1);
+
+        return s3c24xx_register_clock(&divclk->clk);
+}
+
+static inline struct clk *s3c24xx_pwmclk_tclk(unsigned int id)
+{
+        return (id >= 2) ? &clk_timer_tclk[1] : &clk_timer_tclk[0];
+}
+
+static inline struct clk *s3c24xx_pwmclk_tdiv(unsigned int id)
+{
+        return &clk_timer_tdiv[id].clk;
+}
+
+static int clk_pwm_tin_set_parent(struct clk *clk, struct clk *parent)
+{
+        unsigned int id = clk->id;
+        unsigned long tcfg1;
+        unsigned long flags;
+        unsigned long bits;
+        unsigned long shift = S3C2410_TCFG1_SHIFT(id);
+
+        if (parent == s3c24xx_pwmclk_tclk(id))
+                bits = S3C_TCFG1_MUX_TCLK << shift;
+        else if (parent == s3c24xx_pwmclk_tdiv(id))
+                bits = clk_pwm_tdiv_bits(to_tdiv(parent)) << shift;
+        else
+                return -EINVAL;
+
+        clk->parent = parent;
+
+        local_irq_save(flags);
+
+        tcfg1 = __raw_readl(S3C2410_TCFG1);
+        tcfg1 &= ~(S3C2410_TCFG1_MUX_MASK << shift);
+        __raw_writel(tcfg1 | bits, S3C2410_TCFG1);
+
+        local_irq_restore(flags);
+
+        return 0;
+}
+
+static struct clk_ops clk_tin_ops = {
+        .set_parent     = clk_pwm_tin_set_parent,
+};
+
+static struct clk clk_tin[] = {
+        [0]     = {
+                .name   = "pwm-tin",
+                .id     = 0,
+                .ops    = &clk_tin_ops,
+        },
+        [1]     = {
+                .name   = "pwm-tin",
+                .id     = 1,
+                .ops    = &clk_tin_ops,
+        },
+        [2]     = {
+                .name   = "pwm-tin",
+                .id     = 2,
+                .ops    = &clk_tin_ops,
+        },
+        [3]     = {
+                .name   = "pwm-tin",
+                .id     = 3,
+                .ops    = &clk_tin_ops,
+        },
+        [4]     = {
+                .name   = "pwm-tin",
+                .id     = 4,
+                .ops    = &clk_tin_ops,
+        },
+};
+
+static __init int clk_pwm_tin_register(struct clk *pwm)
+{
+        unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+        unsigned int id = pwm->id;
+
+        struct clk *parent;
+        int ret;
+
+        ret = s3c24xx_register_clock(pwm);
+        if (ret < 0)
+                return ret;
+
+        tcfg1 >>= S3C2410_TCFG1_SHIFT(id);
+        tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+        if (pwm_cfg_src_is_tclk(tcfg1))
+                parent = s3c24xx_pwmclk_tclk(id);
+        else
+                parent = s3c24xx_pwmclk_tdiv(id);
+
+        return clk_set_parent(pwm, parent);
+}
+
+/**
+ * s3c_pwmclk_init() - initialise pwm clocks
+ *
+ * Initialise and register the clocks which provide the inputs for the
+ * pwm timer blocks.
+ *
+ * Note, this call is required by the time core, so must be called after
+ * the base clocks are added and before any of the initcalls are run.
+ */
+__init void s3c_pwmclk_init(void)
+{
+        struct clk *clk_timers;
+        unsigned int clk;
+        int ret;
+
+        clk_timers = clk_get(NULL, "timers");
+        if (IS_ERR(clk_timers)) {
+                printk(KERN_ERR "%s: no parent clock\n", __func__);
+                return;
+        }
+
+        for (clk = 0; clk < ARRAY_SIZE(clk_timer_scaler); clk++)
+                clk_timer_scaler[clk].parent = clk_timers;
+
+        s3c_register_clocks(clk_timer_scaler, ARRAY_SIZE(clk_timer_scaler));
+        s3c_register_clocks(clk_timer_tclk, ARRAY_SIZE(clk_timer_tclk));
+
+        for (clk = 0; clk < ARRAY_SIZE(clk_timer_tdiv); clk++) {
+                ret = clk_pwm_tdiv_register(clk);
+
+                if (ret < 0) {
+                        printk(KERN_ERR "error adding pwm%d tdiv clock\n", clk);
+                        return;
+                }
+        }
+
+        for (clk = 0; clk < ARRAY_SIZE(clk_tin); clk++) {
+                ret = clk_pwm_tin_register(&clk_tin[clk]);
+                if (ret < 0) {
+                        printk(KERN_ERR "error adding pwm%d tin clock\n", clk);
+                        return;
+                }
+        }
+}