1 files changed, 431 insertions, 0 deletions

diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c
new file mode 100644
index 000000000000..f2a1c7abf4d9
--- /dev/null
+++ b/drivers/clk/rockchip/clk-pll.c
@@ -0,0 +1,431 @@
+/*
+ * Copyright (c) 2014 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko@sntech.de>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <asm/div64.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+#include "clk.h"
+
+#define PLL_MODE_MASK           0x3
+#define PLL_MODE_SLOW           0x0
+#define PLL_MODE_NORM           0x1
+#define PLL_MODE_DEEP           0x2
+
+struct rockchip_clk_pll {
+        struct clk_hw           hw;
+
+        struct clk_mux          pll_mux;
+        const struct clk_ops    *pll_mux_ops;
+
+        struct notifier_block   clk_nb;
+        bool                    rate_change_remuxed;
+
+        void __iomem            *reg_base;
+        int                     lock_offset;
+        unsigned int            lock_shift;
+        enum rockchip_pll_type  type;
+        const struct rockchip_pll_rate_table *rate_table;
+        unsigned int            rate_count;
+        spinlock_t              *lock;
+};
+
+#define to_rockchip_clk_pll(_hw) container_of(_hw, struct rockchip_clk_pll, hw)
+#define to_rockchip_clk_pll_nb(nb) \
+                        container_of(nb, struct rockchip_clk_pll, clk_nb)
+
+static const struct rockchip_pll_rate_table *rockchip_get_pll_settings(
+                            struct rockchip_clk_pll *pll, unsigned long rate)
+{
+        const struct rockchip_pll_rate_table  *rate_table = pll->rate_table;
+        int i;
+
+        for (i = 0; i < pll->rate_count; i++) {
+                if (rate == rate_table[i].rate)
+                        return &rate_table[i];
+        }
+
+        return NULL;
+}
+
+static long rockchip_pll_round_rate(struct clk_hw *hw,
+                            unsigned long drate, unsigned long *prate)
+{
+        struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
+        const struct rockchip_pll_rate_table *rate_table = pll->rate_table;
+        int i;
+
+        /* Assumming rate_table is in descending order */
+        for (i = 0; i < pll->rate_count; i++) {
+                if (drate >= rate_table[i].rate)
+                        return rate_table[i].rate;
+        }
+
+        /* return minimum supported value */
+        return rate_table[i - 1].rate;
+}
+
+/*
+ * Wait for the pll to reach the locked state.
+ * The calling set_rate function is responsible for making sure the
+ * grf regmap is available.
+ */
+static int rockchip_pll_wait_lock(struct rockchip_clk_pll *pll)
+{
+        struct regmap *grf = rockchip_clk_get_grf();
+        unsigned int val;
+        int delay = 24000000, ret;
+
+        while (delay > 0) {
+                ret = regmap_read(grf, pll->lock_offset, &val);
+                if (ret) {
+                        pr_err("%s: failed to read pll lock status: %d\n",
+                               __func__, ret);
+                        return ret;
+                }
+
+                if (val & BIT(pll->lock_shift))
+                        return 0;
+                delay--;
+        }
+
+        pr_err("%s: timeout waiting for pll to lock\n", __func__);
+        return -ETIMEDOUT;
+}
+
+/**
+ * Set pll mux when changing the pll rate.
+ * This makes sure to move the pll mux away from the actual pll before
+ * changing its rate and back to the original parent after the change.
+ */
+static int rockchip_pll_notifier_cb(struct notifier_block *nb,
+                                        unsigned long event, void *data)
+{
+        struct rockchip_clk_pll *pll = to_rockchip_clk_pll_nb(nb);
+        struct clk_mux *pll_mux = &pll->pll_mux;
+        const struct clk_ops *pll_mux_ops = pll->pll_mux_ops;
+        int cur_parent;
+
+        switch (event) {
+        case PRE_RATE_CHANGE:
+                cur_parent = pll_mux_ops->get_parent(&pll_mux->hw);
+                if (cur_parent == PLL_MODE_NORM) {
+                        pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_SLOW);
+                        pll->rate_change_remuxed = 1;
+                }
+                break;
+        case POST_RATE_CHANGE:
+                if (pll->rate_change_remuxed) {
+                        pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_NORM);
+                        pll->rate_change_remuxed = 0;
+                }
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
+/**
+ * PLL used in RK3066, RK3188 and RK3288
+ */
+
+#define RK3066_PLL_RESET_DELAY(nr)      ((nr * 500) / 24 + 1)
+
+#define RK3066_PLLCON(i)                (i * 0x4)
+#define RK3066_PLLCON0_OD_MASK          0xf
+#define RK3066_PLLCON0_OD_SHIFT         0
+#define RK3066_PLLCON0_NR_MASK          0x3f
+#define RK3066_PLLCON0_NR_SHIFT         8
+#define RK3066_PLLCON1_NF_MASK          0x1fff
+#define RK3066_PLLCON1_NF_SHIFT         0
+#define RK3066_PLLCON2_BWADJ_MASK       0xfff
+#define RK3066_PLLCON2_BWADJ_SHIFT      0
+#define RK3066_PLLCON3_RESET            (1 << 5)
+#define RK3066_PLLCON3_PWRDOWN          (1 << 1)
+#define RK3066_PLLCON3_BYPASS           (1 << 0)
+
+static unsigned long rockchip_rk3066_pll_recalc_rate(struct clk_hw *hw,
+                                                     unsigned long prate)
+{
+        struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
+        u64 nf, nr, no, rate64 = prate;
+        u32 pllcon;
+
+        pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(3));
+        if (pllcon & RK3066_PLLCON3_BYPASS) {
+                pr_debug("%s: pll %s is bypassed\n", __func__,
+                        __clk_get_name(hw->clk));
+                return prate;
+        }
+
+        pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1));
+        nf = (pllcon >> RK3066_PLLCON1_NF_SHIFT) & RK3066_PLLCON1_NF_MASK;
+
+        pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0));
+        nr = (pllcon >> RK3066_PLLCON0_NR_SHIFT) & RK3066_PLLCON0_NR_MASK;
+        no = (pllcon >> RK3066_PLLCON0_OD_SHIFT) & RK3066_PLLCON0_OD_MASK;
+
+        rate64 *= (nf + 1);
+        do_div(rate64, nr + 1);
+        do_div(rate64, no + 1);
+
+        return (unsigned long)rate64;
+}
+
+static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate,
+                                        unsigned long prate)
+{
+        struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
+        const struct rockchip_pll_rate_table *rate;
+        unsigned long old_rate = rockchip_rk3066_pll_recalc_rate(hw, prate);
+        struct regmap *grf = rockchip_clk_get_grf();
+        int ret;
+
+        if (IS_ERR(grf)) {
+                pr_debug("%s: grf regmap not available, aborting rate change\n",
+                         __func__);
+                return PTR_ERR(grf);
+        }
+
+        pr_debug("%s: changing %s from %lu to %lu with a parent rate of %lu\n",
+                 __func__, __clk_get_name(hw->clk), old_rate, drate, prate);
+
+        /* Get required rate settings from table */
+        rate = rockchip_get_pll_settings(pll, drate);
+        if (!rate) {
+                pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
+                        drate, __clk_get_name(hw->clk));
+                return -EINVAL;
+        }
+
+        pr_debug("%s: rate settings for %lu (nr, no, nf): (%d, %d, %d)\n",
+                 __func__, rate->rate, rate->nr, rate->no, rate->nf);
+
+        /* enter reset mode */
+        writel(HIWORD_UPDATE(RK3066_PLLCON3_RESET, RK3066_PLLCON3_RESET, 0),
+               pll->reg_base + RK3066_PLLCON(3));
+
+        /* update pll values */
+        writel(HIWORD_UPDATE(rate->nr - 1, RK3066_PLLCON0_NR_MASK,
+                                           RK3066_PLLCON0_NR_SHIFT) |
+               HIWORD_UPDATE(rate->no - 1, RK3066_PLLCON0_OD_MASK,
+                                           RK3066_PLLCON0_OD_SHIFT),
+               pll->reg_base + RK3066_PLLCON(0));
+
+        writel_relaxed(HIWORD_UPDATE(rate->nf - 1, RK3066_PLLCON1_NF_MASK,
+                                                   RK3066_PLLCON1_NF_SHIFT),
+                       pll->reg_base + RK3066_PLLCON(1));
+        writel_relaxed(HIWORD_UPDATE(rate->bwadj, RK3066_PLLCON2_BWADJ_MASK,
+                                                  RK3066_PLLCON2_BWADJ_SHIFT),
+                       pll->reg_base + RK3066_PLLCON(2));
+
+        /* leave reset and wait the reset_delay */
+        writel(HIWORD_UPDATE(0, RK3066_PLLCON3_RESET, 0),
+               pll->reg_base + RK3066_PLLCON(3));
+        udelay(RK3066_PLL_RESET_DELAY(rate->nr));
+
+        /* wait for the pll to lock */
+        ret = rockchip_pll_wait_lock(pll);
+        if (ret) {
+                pr_warn("%s: pll did not lock, trying to restore old rate %lu\n",
+                        __func__, old_rate);
+                rockchip_rk3066_pll_set_rate(hw, old_rate, prate);
+        }
+
+        return ret;
+}
+
+static int rockchip_rk3066_pll_enable(struct clk_hw *hw)
+{
+        struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
+
+        writel(HIWORD_UPDATE(0, RK3066_PLLCON3_PWRDOWN, 0),
+               pll->reg_base + RK3066_PLLCON(3));
+
+        return 0;
+}
+
+static void rockchip_rk3066_pll_disable(struct clk_hw *hw)
+{
+        struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
+
+        writel(HIWORD_UPDATE(RK3066_PLLCON3_PWRDOWN,
+                             RK3066_PLLCON3_PWRDOWN, 0),
+               pll->reg_base + RK3066_PLLCON(3));
+}
+
+static int rockchip_rk3066_pll_is_enabled(struct clk_hw *hw)
+{
+        struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
+        u32 pllcon = readl(pll->reg_base + RK3066_PLLCON(3));
+
+        return !(pllcon & RK3066_PLLCON3_PWRDOWN);
+}
+
+static const struct clk_ops rockchip_rk3066_pll_clk_norate_ops = {
+        .recalc_rate = rockchip_rk3066_pll_recalc_rate,
+        .enable = rockchip_rk3066_pll_enable,
+        .disable = rockchip_rk3066_pll_disable,
+        .is_enabled = rockchip_rk3066_pll_is_enabled,
+};
+
+static const struct clk_ops rockchip_rk3066_pll_clk_ops = {
+        .recalc_rate = rockchip_rk3066_pll_recalc_rate,
+        .round_rate = rockchip_pll_round_rate,
+        .set_rate = rockchip_rk3066_pll_set_rate,
+        .enable = rockchip_rk3066_pll_enable,
+        .disable = rockchip_rk3066_pll_disable,
+        .is_enabled = rockchip_rk3066_pll_is_enabled,
+};
+
+/*
+ * Common registering of pll clocks
+ */
+
+struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
+                const char *name, const char **parent_names, u8 num_parents,
+                void __iomem *base, int con_offset, int grf_lock_offset,
+                int lock_shift, int mode_offset, int mode_shift,
+                struct rockchip_pll_rate_table *rate_table,
+                spinlock_t *lock)
+{
+        const char *pll_parents[3];
+        struct clk_init_data init;
+        struct rockchip_clk_pll *pll;
+        struct clk_mux *pll_mux;
+        struct clk *pll_clk, *mux_clk;
+        char pll_name[20];
+        int ret;
+
+        if (num_parents != 2) {
+                pr_err("%s: needs two parent clocks\n", __func__);
+                return ERR_PTR(-EINVAL);
+        }
+
+        /* name the actual pll */
+        snprintf(pll_name, sizeof(pll_name), "pll_%s", name);
+
+        pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+        if (!pll)
+                return ERR_PTR(-ENOMEM);
+
+        init.name = pll_name;
+
+        /* keep all plls untouched for now */
+        init.flags = CLK_IGNORE_UNUSED;
+
+        init.parent_names = &parent_names[0];
+        init.num_parents = 1;
+
+        if (rate_table) {
+                int len;
+
+                /* find count of rates in rate_table */
+                for (len = 0; rate_table[len].rate != 0; )
+                        len++;
+
+                pll->rate_count = len;
+                pll->rate_table = kmemdup(rate_table,
+                                        pll->rate_count *
+                                        sizeof(struct rockchip_pll_rate_table),
+                                        GFP_KERNEL);
+                WARN(!pll->rate_table,
+                        "%s: could not allocate rate table for %s\n",
+                        __func__, name);
+        }
+
+        switch (pll_type) {
+        case pll_rk3066:
+                if (!pll->rate_table)
+                        init.ops = &rockchip_rk3066_pll_clk_norate_ops;
+                else
+                        init.ops = &rockchip_rk3066_pll_clk_ops;
+                break;
+        default:
+                pr_warn("%s: Unknown pll type for pll clk %s\n",
+                        __func__, name);
+        }
+
+        pll->hw.init = &init;
+        pll->type = pll_type;
+        pll->reg_base = base + con_offset;
+        pll->lock_offset = grf_lock_offset;
+        pll->lock_shift = lock_shift;
+        pll->lock = lock;
+        pll->clk_nb.notifier_call = rockchip_pll_notifier_cb;
+
+        pll_clk = clk_register(NULL, &pll->hw);
+        if (IS_ERR(pll_clk)) {
+                pr_err("%s: failed to register pll clock %s : %ld\n",
+                        __func__, name, PTR_ERR(pll_clk));
+                mux_clk = pll_clk;
+                goto err_pll;
+        }
+
+        ret = clk_notifier_register(pll_clk, &pll->clk_nb);
+        if (ret) {
+                pr_err("%s: failed to register clock notifier for %s : %d\n",
+                                __func__, name, ret);
+                mux_clk = ERR_PTR(ret);
+                goto err_pll_notifier;
+        }
+
+        /* create the mux on top of the real pll */
+        pll->pll_mux_ops = &clk_mux_ops;
+        pll_mux = &pll->pll_mux;
+
+        /* the actual muxing is xin24m, pll-output, xin32k */
+        pll_parents[0] = parent_names[0];
+        pll_parents[1] = pll_name;
+        pll_parents[2] = parent_names[1];
+
+        init.name = name;
+        init.flags = CLK_SET_RATE_PARENT;
+        init.ops = pll->pll_mux_ops;
+        init.parent_names = pll_parents;
+        init.num_parents = ARRAY_SIZE(pll_parents);
+
+        pll_mux->reg = base + mode_offset;
+        pll_mux->shift = mode_shift;
+        pll_mux->mask = PLL_MODE_MASK;
+        pll_mux->flags = 0;
+        pll_mux->lock = lock;
+        pll_mux->hw.init = &init;
+
+        if (pll_type == pll_rk3066)
+                pll_mux->flags |= CLK_MUX_HIWORD_MASK;
+
+        mux_clk = clk_register(NULL, &pll_mux->hw);
+        if (IS_ERR(mux_clk))
+                goto err_mux;
+
+        return mux_clk;
+
+err_mux:
+        ret = clk_notifier_unregister(pll_clk, &pll->clk_nb);
+        if (ret) {
+                pr_err("%s: could not unregister clock notifier in error path : %d\n",
+                       __func__, ret);
+                return mux_clk;
+        }
+err_pll_notifier:
+        clk_unregister(pll_clk);
+err_pll:
+        kfree(pll);
+        return mux_clk;
+}