[PATCH v4 04/13] clk: rockchip: add clock type for pll clocks and pll used on rk3066
Heiko Stübner
heiko at sntech.de
Sun Jun 22 13:44:41 PDT 2014
All known Rockchip SoCs down to the RK28xx (ARM9) use a similar pattern to
handle their plls:
|--\
xin32k ----------------|mux\
xin24m -----| pll |----|pll|--- pll output
\---------------|src/
|--/
The pll output is sourced from 1 of 3 sources, the actual pll being one of
them. To change the pll frequency it is imperative to remux it to another
source beforehand. This is done by adding a clock-listener to the pll that
handles the remuxing before and after the rate change.
The output mux is implemented as a separate clock to make use of already
existing common-clock features for disabling the pll if one of the other
two sources is used.
Signed-off-by: Heiko Stuebner <heiko at sntech.de>
---
drivers/clk/rockchip/Makefile | 1 +
drivers/clk/rockchip/clk-pll.c | 431 +++++++++++++++++++++++++++++++++++++++++
drivers/clk/rockchip/clk.c | 35 ++++
drivers/clk/rockchip/clk.h | 74 +++++++
4 files changed, 541 insertions(+)
create mode 100644 drivers/clk/rockchip/clk-pll.c
diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
index 0068a8b..2cb9164 100644
--- a/drivers/clk/rockchip/Makefile
+++ b/drivers/clk/rockchip/Makefile
@@ -4,3 +4,4 @@
obj-y += clk-rockchip.o
obj-y += clk.o
+obj-y += clk-pll.o
diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c
new file mode 100644
index 0000000..f2a1c7a
--- /dev/null
+++ b/drivers/clk/rockchip/clk-pll.c
@@ -0,0 +1,431 @@
+/*
+ * Copyright (c) 2014 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko at 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;
+}
diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index 0bffa1b..44abcce 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -23,6 +23,8 @@
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
#include "clk.h"
/**
@@ -105,11 +107,15 @@ static DEFINE_SPINLOCK(clk_lock);
static struct clk **clk_table;
static void __iomem *reg_base;
static struct clk_onecell_data clk_data;
+static struct device_node *cru_node;
+static struct regmap *grf;
void __init rockchip_clk_init(struct device_node *np, void __iomem *base,
unsigned long nr_clks)
{
reg_base = base;
+ cru_node = np;
+ grf = ERR_PTR(-EPROBE_DEFER);
clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
if (!clk_table)
@@ -120,12 +126,41 @@ void __init rockchip_clk_init(struct device_node *np, void __iomem *base,
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
}
+struct regmap *rockchip_clk_get_grf(void)
+{
+ if (IS_ERR(grf))
+ grf = syscon_regmap_lookup_by_phandle(cru_node, "rockchip,grf");
+ return grf;
+}
+
void rockchip_clk_add_lookup(struct clk *clk, unsigned int id)
{
if (clk_table && id)
clk_table[id] = clk;
}
+void __init rockchip_clk_register_plls(struct rockchip_pll_clock *list,
+ unsigned int nr_pll, int grf_lock_offset)
+{
+ struct clk *clk;
+ int idx;
+
+ for (idx = 0; idx < nr_pll; idx++, list++) {
+ clk = rockchip_clk_register_pll(list->type, list->name,
+ list->parent_names, list->num_parents,
+ reg_base, list->con_offset, grf_lock_offset,
+ list->lock_shift, list->mode_offset,
+ list->mode_shift, list->rate_table, &clk_lock);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s\n", __func__,
+ list->name);
+ continue;
+ }
+
+ rockchip_clk_add_lookup(clk, list->id);
+ }
+}
+
void __init rockchip_clk_register_branches(
struct rockchip_clk_branch *list,
unsigned int nr_clk)
diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
index 5b051b0..fb7ce85 100644
--- a/drivers/clk/rockchip/clk.h
+++ b/drivers/clk/rockchip/clk.h
@@ -40,6 +40,77 @@
#define RK2928_SOFTRST_CON(x) (x * 0x4 + 0x110)
#define RK2928_MISC_CON 0x134
+enum rockchip_pll_type {
+ pll_rk3066,
+};
+
+#define RK3066_PLL_RATE(_rate, _nr, _nf, _no) \
+{ \
+ .rate = _rate##U, \
+ .nr = _nr, \
+ .nf = _nf, \
+ .no = _no, \
+ .bwadj = (_nf >> 1), \
+}
+
+struct rockchip_pll_rate_table {
+ unsigned long rate;
+ unsigned int nr;
+ unsigned int nf;
+ unsigned int no;
+ unsigned int bwadj;
+};
+
+/**
+ * struct rockchip_pll_clock: information about pll clock
+ * @id: platform specific id of the clock.
+ * @name: name of this pll clock.
+ * @parent_name: name of the parent clock.
+ * @flags: optional flags for basic clock.
+ * @con_offset: offset of the register for configuring the PLL.
+ * @mode_offset: offset of the register for configuring the PLL-mode.
+ * @mode_shift: offset inside the mode-register for the mode of this pll.
+ * @lock_shift: offset inside the lock register for the lock status.
+ * @type: Type of PLL to be registered.
+ * @rate_table: Table of usable pll rates
+ */
+struct rockchip_pll_clock {
+ unsigned int id;
+ const char *name;
+ const char **parent_names;
+ u8 num_parents;
+ unsigned long flags;
+ int con_offset;
+ int mode_offset;
+ int mode_shift;
+ int lock_shift;
+ enum rockchip_pll_type type;
+ struct rockchip_pll_rate_table *rate_table;
+};
+
+#define PLL(_type, _id, _name, _pnames, _flags, _con, _mode, _mshift, \
+ _lshift, _rtable) \
+ { \
+ .id = _id, \
+ .type = _type, \
+ .name = _name, \
+ .parent_names = _pnames, \
+ .num_parents = ARRAY_SIZE(_pnames), \
+ .flags = CLK_GET_RATE_NOCACHE | _flags, \
+ .con_offset = _con, \
+ .mode_offset = _mode, \
+ .mode_shift = _mshift, \
+ .lock_shift = _lshift, \
+ .rate_table = _rtable, \
+ }
+
+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 reg_mode, int mode_shift,
+ struct rockchip_pll_rate_table *rate_table,
+ spinlock_t *lock);
+
#define PNAME(x) static const char *x[] __initconst
enum rockchip_clk_branch_type {
@@ -243,8 +314,11 @@ struct rockchip_clk_branch {
void rockchip_clk_init(struct device_node *np, void __iomem *base,
unsigned long nr_clks);
+struct regmap *rockchip_clk_get_grf(void);
void rockchip_clk_add_lookup(struct clk *clk, unsigned int id);
void rockchip_clk_register_branches(struct rockchip_clk_branch *clk_list,
unsigned int nr_clk);
+void rockchip_clk_register_plls(struct rockchip_pll_clock *pll_list,
+ unsigned int nr_pll, int grf_lock_offset);
#endif
--
1.9.0
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