sh: SH7722 clock framework support.

This adds support for the SH7722 (MobileR) to the clock framework.

Signed-off-by: dmitry pervushin <dimka@nomadgs.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 600 insertions, 0 deletions

diff --git a/arch/sh/kernel/cpu/sh4a/clock-sh7722.c b/arch/sh/kernel/cpu/sh4a/clock-sh7722.c
new file mode 100644
index 000000000000..29090035bc5b
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4a/clock-sh7722.c
@@ -0,0 +1,600 @@
+/*
+ * arch/sh/kernel/cpu/sh4a/clock-sh7722.c
+ *
+ * SH7722 support for the clock framework
+ *
+ * Copyright (c) 2006-2007 Nomad Global Solutions Inc
+ * Based on code for sh7343 by Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <asm/clock.h>
+#include <asm/freq.h>
+
+#define SH7722_PLL_FREQ (32000000/8)
+#define N  (-1)
+#define NM (-2)
+#define ROUND_NEAREST 0
+#define ROUND_DOWN -1
+#define ROUND_UP   +1
+
+static int adjust_algos[][3] = {
+        {},     /* NO_CHANGE */
+        { NM, N, 1 },   /* N:1, N:1 */
+        { 3, 2, 2 },    /* 3:2:2 */
+        { 5, 2, 2 },    /* 5:2:2 */
+        { N, 1, 1 },    /* N:1:1 */
+
+        { N, 1 },       /* N:1 */
+
+        { N, 1 },       /* N:1 */
+        { 3, 2 },
+        { 4, 3 },
+        { 5, 4 },
+
+        { N, 1 }
+};
+
+static unsigned long adjust_pair_of_clocks(unsigned long r1, unsigned long r2,
+                        int m1, int m2, int round_flag)
+{
+        unsigned long rem, div;
+        int the_one = 0;
+
+        pr_debug( "Actual values: r1 = %ld\n", r1);
+        pr_debug( "...............r2 = %ld\n", r2);
+
+        if (m1 == m2) {
+                r2 = r1;
+                pr_debug( "setting equal rates: r2 now %ld\n", r2);
+        } else if ((m2 == N  && m1 == 1) ||
+                   (m2 == NM && m1 == N)) { /* N:1 or NM:N */
+                pr_debug( "Setting rates as 1:N (N:N*M)\n");
+                rem = r2 % r1;
+                pr_debug( "...remainder = %ld\n", rem);
+                if (rem) {
+                        div = r2 / r1;
+                        pr_debug( "...div = %ld\n", div);
+                        switch (round_flag) {
+                        case ROUND_NEAREST:
+                                the_one = rem >= r1/2 ? 1 : 0; break;
+                        case ROUND_UP:
+                                the_one = 1; break;
+                        case ROUND_DOWN:
+                                the_one = 0; break;
+                        }
+
+                        r2 = r1 * (div + the_one);
+                        pr_debug( "...setting r2 to %ld\n", r2);
+                }
+        } else if ((m2 == 1  && m1 == N) ||
+                   (m2 == N && m1 == NM)) { /* 1:N or N:NM */
+                pr_debug( "Setting rates as N:1 (N*M:N)\n");
+                rem = r1 % r2;
+                pr_debug( "...remainder = %ld\n", rem);
+                if (rem) {
+                        div = r1 / r2;
+                        pr_debug( "...div = %ld\n", div);
+                        switch (round_flag) {
+                        case ROUND_NEAREST:
+                                the_one = rem > r2/2 ? 1 : 0; break;
+                        case ROUND_UP:
+                                the_one = 0; break;
+                        case ROUND_DOWN:
+                                the_one = 1; break;
+                        }
+
+                        r2 = r1 / (div + the_one);
+                        pr_debug( "...setting r2 to %ld\n", r2);
+                }
+        } else { /* value:value */
+                pr_debug( "Setting rates as %d:%d\n", m1, m2);
+                div = r1 / m1;
+                r2 = div * m2;
+                pr_debug( "...div = %ld\n", div);
+                pr_debug( "...setting r2 to %ld\n", r2);
+        }
+
+        return r2;
+}
+
+static void adjust_clocks(int originate, int *l, unsigned long v[],
+                          int n_in_line)
+{
+        int x;
+
+        pr_debug( "Go down from %d...\n", originate);
+        /* go up recalculation clocks */
+        for (x = originate; x>0; x -- )
+                v[x-1] = adjust_pair_of_clocks(v[x], v[x-1],
+                                        l[x], l[x-1],
+                                        ROUND_UP);
+
+        pr_debug( "Go up from %d...\n", originate);
+        /* go down recalculation clocks */
+        for (x = originate; x<n_in_line - 1; x ++ )
+                v[x+1] = adjust_pair_of_clocks(v[x], v[x+1],
+                                        l[x], l[x+1],
+                                        ROUND_UP);
+}
+
+
+/*
+ * SH7722 uses a common set of multipliers and divisors, so this
+ * is quite simple..
+ */
+
+/*
+ * Instead of having two separate multipliers/divisors set, like this:
+ *
+ * static int multipliers[] = { 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
+ * static int divisors[] = { 1, 3, 2, 5, 3, 4, 5, 6, 8, 10, 12, 16, 20 };
+ *
+ * I created the divisors2 array, which is used to calculate rate like
+ *   rate = parent * 2 / divisors2[ divisor ];
+*/
+static int divisors2[] = { 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 32, 40 };
+
+static void master_clk_init(struct clk *clk)
+{
+        clk_set_rate(clk, clk_get_rate(clk));
+}
+
+static void master_clk_recalc(struct clk *clk)
+{
+        unsigned long frqcr = ctrl_inl(FRQCR);
+
+        clk->rate = CONFIG_SH_PCLK_FREQ * (1 + (frqcr >> 24 & 0xF));
+}
+
+static int master_clk_setrate(struct clk *clk, unsigned long rate, int id)
+{
+        int div = rate / SH7722_PLL_FREQ;
+        int master_divs[] = { 2, 3, 4, 6, 8, 16 };
+        int index;
+        unsigned long frqcr;
+
+        if (rate < SH7722_PLL_FREQ * 2)
+                return -EINVAL;
+
+        for (index = 1; index < ARRAY_SIZE(master_divs); index++)
+                if (div >= master_divs[index - 1] && div < master_divs[index])
+                        break;
+
+        if (index >= ARRAY_SIZE(master_divs))
+                index = ARRAY_SIZE(master_divs);
+        div = master_divs[index - 1];
+
+        frqcr = ctrl_inl(FRQCR);
+        frqcr &= ~(0xF << 24);
+        frqcr |= ( (div-1) << 24);
+        ctrl_outl(frqcr, FRQCR);
+
+        return 0;
+}
+
+static struct clk_ops sh7722_master_clk_ops = {
+        .init = master_clk_init,
+        .recalc = master_clk_recalc,
+        .set_rate = master_clk_setrate,
+};
+
+struct frqcr_context {
+        unsigned mask;
+        unsigned shift;
+};
+
+struct frqcr_context sh7722_get_clk_context(const char *name)
+{
+        struct frqcr_context ctx = { 0, };
+
+        if (!strcmp(name, "peripheral_clk")) {
+                ctx.shift = 0;
+                ctx.mask = 0xF;
+        } else if (!strcmp(name, "sdram_clk")) {
+                ctx.shift = 4;
+                ctx.mask = 0xF;
+        } else if (!strcmp(name, "bus_clk")) {
+                ctx.shift = 8;
+                ctx.mask = 0xF;
+        } else if (!strcmp(name, "sh_clk")) {
+                ctx.shift = 12;
+                ctx.mask = 0xF;
+        } else if (!strcmp(name, "umem_clk")) {
+                ctx.shift = 16;
+                ctx.mask = 0xF;
+        } else if (!strcmp(name, "cpu_clk")) {
+                ctx.shift = 20;
+                ctx.mask = 7;
+        }
+        return ctx;
+}
+
+/**
+ * sh7722_find_divisors - find divisor for setting rate
+ *
+ * All sh7722 clocks use the same set of multipliers/divisors. This function
+ * chooses correct divisor to set the rate of clock with parent clock that
+ * generates frequency of 'parent_rate'
+ *
+ * @parent_rate: rate of parent clock
+ * @rate: requested rate to be set
+ */
+static int sh7722_find_divisors(unsigned long parent_rate, unsigned rate)
+{
+        unsigned div2 = parent_rate * 2 / rate;
+        int index;
+
+        if (rate > parent_rate)
+                return -EINVAL;
+
+        for (index = 1; index < ARRAY_SIZE(divisors2); index++) {
+                if (div2 > divisors2[index] && div2 <= divisors2[index])
+                        break;
+        }
+        if (index >= ARRAY_SIZE(divisors2))
+                index = ARRAY_SIZE(divisors2) - 1;
+        return divisors2[index];
+}
+
+static void sh7722_frqcr_recalc(struct clk *clk)
+{
+        struct frqcr_context ctx = sh7722_get_clk_context(clk->name);
+        unsigned long frqcr = ctrl_inl(FRQCR);
+        int index;
+
+        index = (frqcr >> ctx.shift) & ctx.mask;
+        clk->rate = clk->parent->rate * 2 / divisors2[index];
+}
+
+static int sh7722_frqcr_set_rate(struct clk *clk, unsigned long rate,
+                                 int algo_id)
+{
+        struct frqcr_context ctx = sh7722_get_clk_context(clk->name);
+        unsigned long parent_rate = clk->parent->rate;
+        int div;
+        unsigned long frqcr;
+        int err = 0;
+
+        /* pretty invalid */
+        if (parent_rate < rate)
+                return -EINVAL;
+
+        /* look for multiplier/divisor pair */
+        div = sh7722_find_divisors(parent_rate, rate);
+        if (div<0)
+                return div;
+
+        /* calculate new value of clock rate */
+        clk->rate = parent_rate * 2 / div;
+        frqcr = ctrl_inl(FRQCR);
+
+        /* FIXME: adjust as algo_id specifies */
+        if (algo_id != NO_CHANGE) {
+                int originator;
+                char *algo_group_1[] = { "cpu_clk", "umem_clk", "sh_clk" };
+                char *algo_group_2[] = { "sh_clk", "bus_clk" };
+                char *algo_group_3[] = { "sh_clk", "sdram_clk" };
+                char *algo_group_4[] = { "bus_clk", "peripheral_clk" };
+                char *algo_group_5[] = { "cpu_clk", "peripheral_clk" };
+                char **algo_current = NULL;
+                /* 3 is the maximum number of clocks in relation */
+                struct clk *ck[3];
+                unsigned long values[3]; /* the same comment as above */
+                int part_length = -1;
+                int i;
+
+                /*
+                 * all the steps below only required if adjustion was
+                 * requested
+                 */
+                if (algo_id == IUS_N1_N1 ||
+                    algo_id == IUS_322 ||
+                    algo_id == IUS_522 ||
+                    algo_id == IUS_N11) {
+                        algo_current = algo_group_1;
+                        part_length = 3;
+                }
+                if (algo_id == SB_N1) {
+                        algo_current = algo_group_2;
+                        part_length = 2;
+                }
+                if (algo_id == SB3_N1 ||
+                    algo_id == SB3_32 ||
+                    algo_id == SB3_43 ||
+                    algo_id == SB3_54) {
+                        algo_current = algo_group_3;
+                        part_length = 2;
+                }
+                if (algo_id == BP_N1) {
+                        algo_current = algo_group_4;
+                        part_length = 2;
+                }
+                if (algo_id == IP_N1) {
+                        algo_current = algo_group_5;
+                        part_length = 2;
+                }
+                if (!algo_current)
+                        goto incorrect_algo_id;
+
+                originator = -1;
+                for (i = 0; i < part_length; i ++ ) {
+                        if (originator >= 0 && !strcmp(clk->name,
+                                                       algo_current[i]))
+                                originator = i;
+                        ck[i] = clk_get(NULL, algo_current[i]);
+                        values[i] = clk_get_rate(ck[i]);
+                }
+
+                if (originator >= 0)
+                        adjust_clocks(originator, adjust_algos[algo_id],
+                                      values, part_length);
+
+                for (i = 0; i < part_length; i ++ ) {
+                        struct frqcr_context part_ctx;
+                        int part_div;
+
+                        if (likely(!err)) {
+                                part_div = sh7722_find_divisors(parent_rate,
+                                                                rate);
+                                if (part_div > 0) {
+                                        part_ctx = sh7722_get_clk_context(
+                                                                ck[i]->name);
+                                        frqcr &= ~(part_ctx.mask <<
+                                                   part_ctx.shift);
+                                        frqcr |= part_div << part_ctx.shift;
+                                } else
+                                        err = part_div;
+                        }
+
+                        ck[i]->ops->recalc(ck[i]);
+                        clk_put(ck[i]);
+                }
+        }
+
+        /* was there any error during recalculation ? If so, bail out.. */
+        if (unlikely(err!=0))
+                goto out_err;
+
+        /* clear FRQCR bits */
+        frqcr &= ~(ctx.mask << ctx.shift);
+        frqcr |= div << ctx.shift;
+
+        /* ...and perform actual change */
+        ctrl_outl(frqcr, FRQCR);
+        return 0;
+
+incorrect_algo_id:
+        return -EINVAL;
+out_err:
+        return err;
+}
+
+static struct clk_ops sh7722_frqcr_clk_ops = {
+        .recalc = sh7722_frqcr_recalc,
+        .set_rate = sh7722_frqcr_set_rate,
+};
+
+/*
+ * clock ops methods for SIU A/B and IrDA clock
+ *
+ */
+static int sh7722_siu_which(struct clk *clk)
+{
+        if (!strcmp(clk->name, "siu_a_clk"))
+                return 0;
+        if (!strcmp(clk->name, "siu_b_clk"))
+                return 1;
+        if (!strcmp(clk->name, "irda_clk"))
+                return 2;
+        return -EINVAL;
+}
+
+static unsigned long sh7722_siu_regs[] = {
+        [0] = SCLKACR,
+        [1] = SCLKBCR,
+        [2] = IrDACLKCR,
+};
+
+static int sh7722_siu_start_stop(struct clk *clk, int enable)
+{
+        int siu = sh7722_siu_which(clk);
+        unsigned long r;
+
+        if (siu < 0)
+                return siu;
+        BUG_ON(siu > 2);
+        r = ctrl_inl(sh7722_siu_regs[siu]);
+        if (enable)
+                ctrl_outl(r & ~(1 << 8), sh7722_siu_regs[siu]);
+        else
+                ctrl_outl(r | (1 << 8), sh7722_siu_regs[siu]);
+        return 0;
+}
+
+static void sh7722_siu_enable(struct clk *clk)
+{
+        sh7722_siu_start_stop(clk, 1);
+}
+
+static void sh7722_siu_disable(struct clk *clk)
+{
+        sh7722_siu_start_stop(clk, 0);
+}
+
+static void sh7722_video_enable(struct clk *clk)
+{
+        unsigned long r;
+
+        r = ctrl_inl(VCLKCR);
+        ctrl_outl( r & ~(1<<8), VCLKCR);
+}
+
+static void sh7722_video_disable(struct clk *clk)
+{
+        unsigned long r;
+
+        r = ctrl_inl(VCLKCR);
+        ctrl_outl( r | (1<<8), VCLKCR);
+}
+
+static int sh7722_video_set_rate(struct clk *clk, unsigned long rate,
+                                 int algo_id)
+{
+        unsigned long r;
+
+        r = ctrl_inl(VCLKCR);
+        r &= ~0x3F;
+        r |= ((clk->parent->rate / rate - 1) & 0x3F);
+        ctrl_outl(r, VCLKCR);
+        return 0;
+}
+
+static void sh7722_video_recalc(struct clk *clk)
+{
+        unsigned long r;
+
+        r = ctrl_inl(VCLKCR);
+        clk->rate = clk->parent->rate / ((r & 0x3F) + 1);
+}
+
+static int sh7722_siu_set_rate(struct clk *clk, unsigned long rate, int algo_id)
+{
+        int siu = sh7722_siu_which(clk);
+        unsigned long r;
+        int div;
+
+        if (siu < 0)
+                return siu;
+        BUG_ON(siu > 2);
+        r = ctrl_inl(sh7722_siu_regs[siu]);
+        div = sh7722_find_divisors(clk->parent->rate, rate);
+        if (div < 0)
+                return div;
+        r = (r & ~0xF) | div;
+        ctrl_outl(r, sh7722_siu_regs[siu]);
+        return 0;
+}
+
+static void sh7722_siu_recalc(struct clk *clk)
+{
+        int siu = sh7722_siu_which(clk);
+        unsigned long r;
+
+        if (siu < 0)
+                return /* siu */ ;
+        BUG_ON(siu > 1);
+        r = ctrl_inl(sh7722_siu_regs[siu]);
+        clk->rate = clk->parent->rate * 2 / divisors2[r & 0xF];
+}
+
+static struct clk_ops sh7722_siu_clk_ops = {
+        .recalc = sh7722_siu_recalc,
+        .set_rate = sh7722_siu_set_rate,
+        .enable = sh7722_siu_enable,
+        .disable = sh7722_siu_disable,
+};
+
+static struct clk_ops sh7722_video_clk_ops = {
+        .recalc = sh7722_video_recalc,
+        .set_rate = sh7722_video_set_rate,
+        .enable = sh7722_video_enable,
+        .disable = sh7722_video_disable,
+};
+/*
+ * and at last, clock definitions themselves
+ */
+static struct clk sh7722_umem_clock = {
+        .name = "umem_clk",
+        .ops = &sh7722_frqcr_clk_ops,
+};
+
+static struct clk sh7722_sh_clock = {
+        .name = "sh_clk",
+        .ops = &sh7722_frqcr_clk_ops,
+};
+
+static struct clk sh7722_peripheral_clock = {
+        .name = "peripheral_clk",
+        .ops = &sh7722_frqcr_clk_ops,
+};
+
+static struct clk sh7722_sdram_clock = {
+        .name = "sdram_clk",
+        .ops = &sh7722_frqcr_clk_ops,
+};
+
+/*
+ * these three clocks - SIU A, SIU B, IrDA - share the same clk_ops
+ * methods of clk_ops determine which register they should access by
+ * examining clk->name field
+ */
+static struct clk sh7722_siu_a_clock = {
+        .name = "siu_a_clk",
+        .ops = &sh7722_siu_clk_ops,
+};
+
+static struct clk sh7722_siu_b_clock = {
+        .name = "siu_b_clk",
+        .ops = &sh7722_siu_clk_ops,
+};
+
+static struct clk sh7722_irda_clock = {
+        .name = "irda_clk",
+        .ops = &sh7722_siu_clk_ops,
+};
+
+static struct clk sh7722_video_clock = {
+        .name = "video_clk",
+        .ops = &sh7722_video_clk_ops,
+};
+
+static struct clk *sh7722_clocks[] = {
+        &sh7722_umem_clock,
+        &sh7722_sh_clock,
+        &sh7722_peripheral_clock,
+        &sh7722_sdram_clock,
+        &sh7722_siu_a_clock,
+        &sh7722_siu_b_clock,
+        &sh7722_irda_clock,
+        &sh7722_video_clock,
+};
+
+/*
+ * init in order: master, module, bus, cpu
+ */
+struct clk_ops *onchip_ops[] = {
+        &sh7722_master_clk_ops,
+        &sh7722_frqcr_clk_ops,
+        &sh7722_frqcr_clk_ops,
+        &sh7722_frqcr_clk_ops,
+};
+
+void __init
+arch_init_clk_ops(struct clk_ops **ops, int type)
+{
+        BUG_ON(type < 0 || type > ARRAY_SIZE(onchip_ops));
+        *ops = onchip_ops[type];
+}
+
+int __init sh7722_clock_init(void)
+{
+        struct clk *master;
+        int i;
+
+        master = clk_get(NULL, "master_clk");
+        for (i = 0; i < ARRAY_SIZE(sh7722_clocks); i++) {
+                pr_debug( "Registering clock '%s'\n", sh7722_clocks[i]->name);
+                sh7722_clocks[i]->parent = master;
+                clk_register(sh7722_clocks[i]);
+        }
+        clk_put(master);
+        return 0;
+}
+arch_initcall(sh7722_clock_init);