CPUs, DDR, etc.) or passed over the clock dividers to be only
then used as an individual reference clock of a target device.
+config CLK_BT1_CCU_DIV
+ bool "Baikal-T1 CCU Dividers support"
+ select RESET_CONTROLLER
+ select MFD_SYSCON
+ default MIPS_BAIKAL_T1
+ help
+ Enable this to support the CCU dividers used to distribute clocks
+ between AXI-bus and system devices coming from CCU PLLs of Baikal-T1
+ SoC. CCU dividers can be either configurable or with fixed divider,
+ either gateable or ungateable. Some of the CCU dividers can be as well
+ used to reset the domains they're supplying clock to.
+
endif
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_CLK_BT1_CCU_PLL) += ccu-pll.o clk-ccu-pll.o
+obj-$(CONFIG_CLK_BT1_CCU_DIV) += ccu-div.o clk-ccu-div.o
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
+ *
+ * Authors:
+ * Serge Semin <Sergey.Semin@baikalelectronics.ru>
+ * Dmitry Dunaev <dmitry.dunaev@baikalelectronics.ru>
+ *
+ * Baikal-T1 CCU Dividers interface driver
+ */
+
+#define pr_fmt(fmt) "bt1-ccu-div: " fmt
+
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/bits.h>
+#include <linux/bitfield.h>
+#include <linux/slab.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/time64.h>
+#include <linux/debugfs.h>
+
+#include "ccu-div.h"
+
+#define CCU_DIV_CTL 0x00
+#define CCU_DIV_CTL_EN BIT(0)
+#define CCU_DIV_CTL_RST BIT(1)
+#define CCU_DIV_CTL_SET_CLKDIV BIT(2)
+#define CCU_DIV_CTL_CLKDIV_FLD 4
+#define CCU_DIV_CTL_CLKDIV_MASK(_width) \
+ GENMASK((_width) + CCU_DIV_CTL_CLKDIV_FLD - 1, CCU_DIV_CTL_CLKDIV_FLD)
+#define CCU_DIV_CTL_LOCK_SHIFTED BIT(27)
+#define CCU_DIV_CTL_LOCK_NORMAL BIT(31)
+
+#define CCU_DIV_RST_DELAY_US 1
+#define CCU_DIV_LOCK_CHECK_RETRIES 50
+
+#define CCU_DIV_CLKDIV_MIN 0
+#define CCU_DIV_CLKDIV_MAX(_mask) \
+ ((_mask) >> CCU_DIV_CTL_CLKDIV_FLD)
+
+/*
+ * Use the next two methods until there are generic field setter and
+ * getter available with non-constant mask support.
+ */
+static inline u32 ccu_div_get(u32 mask, u32 val)
+{
+ return (val & mask) >> CCU_DIV_CTL_CLKDIV_FLD;
+}
+
+static inline u32 ccu_div_prep(u32 mask, u32 val)
+{
+ return (val << CCU_DIV_CTL_CLKDIV_FLD) & mask;
+}
+
+static inline unsigned long ccu_div_lock_delay_ns(unsigned long ref_clk,
+ unsigned long div)
+{
+ u64 ns = 4ULL * (div ?: 1) * NSEC_PER_SEC;
+
+ do_div(ns, ref_clk);
+
+ return ns;
+}
+
+static inline unsigned long ccu_div_calc_freq(unsigned long ref_clk,
+ unsigned long div)
+{
+ return ref_clk / (div ?: 1);
+}
+
+static int ccu_div_var_update_clkdiv(struct ccu_div *div,
+ unsigned long parent_rate,
+ unsigned long divider)
+{
+ unsigned long nd;
+ u32 val = 0;
+ u32 lock;
+ int count;
+
+ nd = ccu_div_lock_delay_ns(parent_rate, divider);
+
+ if (div->features & CCU_DIV_LOCK_SHIFTED)
+ lock = CCU_DIV_CTL_LOCK_SHIFTED;
+ else
+ lock = CCU_DIV_CTL_LOCK_NORMAL;
+
+ regmap_update_bits(div->sys_regs, div->reg_ctl,
+ CCU_DIV_CTL_SET_CLKDIV, CCU_DIV_CTL_SET_CLKDIV);
+
+ /*
+ * Until there is nsec-version of readl_poll_timeout() is available
+ * we have to implement the next polling loop.
+ */
+ count = CCU_DIV_LOCK_CHECK_RETRIES;
+ do {
+ ndelay(nd);
+ regmap_read(div->sys_regs, div->reg_ctl, &val);
+ if (val & lock)
+ return 0;
+ } while (--count);
+
+ return -ETIMEDOUT;
+}
+
+static int ccu_div_var_enable(struct clk_hw *hw)
+{
+ struct clk_hw *parent_hw = clk_hw_get_parent(hw);
+ struct ccu_div *div = to_ccu_div(hw);
+ unsigned long flags;
+ u32 val = 0;
+ int ret;
+
+ if (!parent_hw) {
+ pr_err("Can't enable '%s' with no parent", clk_hw_get_name(hw));
+ return -EINVAL;
+ }
+
+ regmap_read(div->sys_regs, div->reg_ctl, &val);
+ if (val & CCU_DIV_CTL_EN)
+ return 0;
+
+ spin_lock_irqsave(&div->lock, flags);
+ ret = ccu_div_var_update_clkdiv(div, clk_hw_get_rate(parent_hw),
+ ccu_div_get(div->mask, val));
+ if (!ret)
+ regmap_update_bits(div->sys_regs, div->reg_ctl,
+ CCU_DIV_CTL_EN, CCU_DIV_CTL_EN);
+ spin_unlock_irqrestore(&div->lock, flags);
+ if (ret)
+ pr_err("Divider '%s' lock timed out\n", clk_hw_get_name(hw));
+
+ return ret;
+}
+
+static int ccu_div_gate_enable(struct clk_hw *hw)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ unsigned long flags;
+
+ spin_lock_irqsave(&div->lock, flags);
+ regmap_update_bits(div->sys_regs, div->reg_ctl,
+ CCU_DIV_CTL_EN, CCU_DIV_CTL_EN);
+ spin_unlock_irqrestore(&div->lock, flags);
+
+ return 0;
+}
+
+static void ccu_div_gate_disable(struct clk_hw *hw)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ unsigned long flags;
+
+ spin_lock_irqsave(&div->lock, flags);
+ regmap_update_bits(div->sys_regs, div->reg_ctl, CCU_DIV_CTL_EN, 0);
+ spin_unlock_irqrestore(&div->lock, flags);
+}
+
+static int ccu_div_gate_is_enabled(struct clk_hw *hw)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ u32 val = 0;
+
+ regmap_read(div->sys_regs, div->reg_ctl, &val);
+
+ return !!(val & CCU_DIV_CTL_EN);
+}
+
+static unsigned long ccu_div_var_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ unsigned long divider;
+ u32 val = 0;
+
+ regmap_read(div->sys_regs, div->reg_ctl, &val);
+ divider = ccu_div_get(div->mask, val);
+
+ return ccu_div_calc_freq(parent_rate, divider);
+}
+
+static inline unsigned long ccu_div_var_calc_divider(unsigned long rate,
+ unsigned long parent_rate,
+ unsigned int mask)
+{
+ unsigned long divider;
+
+ divider = parent_rate / rate;
+ return clamp_t(unsigned long, divider, CCU_DIV_CLKDIV_MIN,
+ CCU_DIV_CLKDIV_MAX(mask));
+}
+
+static long ccu_div_var_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ unsigned long divider;
+
+ divider = ccu_div_var_calc_divider(rate, *parent_rate, div->mask);
+
+ return ccu_div_calc_freq(*parent_rate, divider);
+}
+
+/*
+ * This method is used for the clock divider blocks, which support the
+ * on-the-fly rate change. So due to lacking the EN bit functionality
+ * they can't be gated before the rate adjustment.
+ */
+static int ccu_div_var_set_rate_slow(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ unsigned long flags, divider;
+ u32 val;
+ int ret;
+
+ divider = ccu_div_var_calc_divider(rate, parent_rate, div->mask);
+ if (divider == 1 && div->features & CCU_DIV_SKIP_ONE) {
+ divider = 0;
+ } else if (div->features & CCU_DIV_SKIP_ONE_TO_THREE) {
+ if (divider == 1 || divider == 2)
+ divider = 0;
+ else if (divider == 3)
+ divider = 4;
+ }
+
+ val = ccu_div_prep(div->mask, divider);
+
+ spin_lock_irqsave(&div->lock, flags);
+ regmap_update_bits(div->sys_regs, div->reg_ctl, div->mask, val);
+ ret = ccu_div_var_update_clkdiv(div, parent_rate, divider);
+ spin_unlock_irqrestore(&div->lock, flags);
+ if (ret)
+ pr_err("Divider '%s' lock timed out\n", clk_hw_get_name(hw));
+
+ return ret;
+}
+
+/*
+ * This method is used for the clock divider blocks, which don't support
+ * the on-the-fly rate change.
+ */
+static int ccu_div_var_set_rate_fast(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ unsigned long flags, divider = 1;
+ u32 val;
+
+ divider = ccu_div_var_calc_divider(rate, parent_rate, div->mask);
+ val = ccu_div_prep(div->mask, divider);
+
+ /*
+ * Also disable the clock divider block if it was enabled by default
+ * or by the bootloader.
+ */
+ spin_lock_irqsave(&div->lock, flags);
+ regmap_update_bits(div->sys_regs, div->reg_ctl,
+ div->mask | CCU_DIV_CTL_EN, val);
+ spin_unlock_irqrestore(&div->lock, flags);
+
+ return 0;
+}
+
+static unsigned long ccu_div_fixed_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+
+ return ccu_div_calc_freq(parent_rate, div->divider);
+}
+
+static long ccu_div_fixed_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+
+ return ccu_div_calc_freq(*parent_rate, div->divider);
+}
+
+static int ccu_div_fixed_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ return 0;
+}
+
+int ccu_div_reset_domain(struct ccu_div *div)
+{
+ unsigned long flags;
+
+ if (!div || !(div->features & CCU_DIV_RESET_DOMAIN))
+ return -EINVAL;
+
+ spin_lock_irqsave(&div->lock, flags);
+ regmap_update_bits(div->sys_regs, div->reg_ctl,
+ CCU_DIV_CTL_RST, CCU_DIV_CTL_RST);
+ spin_unlock_irqrestore(&div->lock, flags);
+
+ /* The next delay must be enough to cover all the resets. */
+ udelay(CCU_DIV_RST_DELAY_US);
+
+ return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+struct ccu_div_dbgfs_bit {
+ struct ccu_div *div;
+ const char *name;
+ u32 mask;
+};
+
+#define CCU_DIV_DBGFS_BIT_ATTR(_name, _mask) { \
+ .name = _name, \
+ .mask = _mask \
+ }
+
+static const struct ccu_div_dbgfs_bit ccu_div_bits[] = {
+ CCU_DIV_DBGFS_BIT_ATTR("div_en", CCU_DIV_CTL_EN),
+ CCU_DIV_DBGFS_BIT_ATTR("div_rst", CCU_DIV_CTL_RST),
+ CCU_DIV_DBGFS_BIT_ATTR("div_bypass", CCU_DIV_CTL_SET_CLKDIV),
+ CCU_DIV_DBGFS_BIT_ATTR("div_lock", CCU_DIV_CTL_LOCK_NORMAL)
+};
+
+#define CCU_DIV_DBGFS_BIT_NUM ARRAY_SIZE(ccu_div_bits)
+
+/*
+ * It can be dangerous to change the Divider settings behind clock framework
+ * back, therefore we don't provide any kernel config based compile time option
+ * for this feature to enable.
+ */
+#undef CCU_DIV_ALLOW_WRITE_DEBUGFS
+#ifdef CCU_DIV_ALLOW_WRITE_DEBUGFS
+
+static int ccu_div_dbgfs_bit_set(void *priv, u64 val)
+{
+ const struct ccu_div_dbgfs_bit *bit = priv;
+ struct ccu_div *div = bit->div;
+ unsigned long flags;
+
+ spin_lock_irqsave(&div->lock, flags);
+ regmap_update_bits(div->sys_regs, div->reg_ctl,
+ bit->mask, val ? bit->mask : 0);
+ spin_unlock_irqrestore(&div->lock, flags);
+
+ return 0;
+}
+
+static int ccu_div_dbgfs_var_clkdiv_set(void *priv, u64 val)
+{
+ struct ccu_div *div = priv;
+ unsigned long flags;
+ u32 data;
+
+ val = clamp_t(u64, val, CCU_DIV_CLKDIV_MIN,
+ CCU_DIV_CLKDIV_MAX(div->mask));
+ data = ccu_div_prep(div->mask, val);
+
+ spin_lock_irqsave(&div->lock, flags);
+ regmap_update_bits(div->sys_regs, div->reg_ctl, div->mask, data);
+ spin_unlock_irqrestore(&div->lock, flags);
+
+ return 0;
+}
+
+#define ccu_div_dbgfs_mode 0644
+
+#else /* !CCU_DIV_ALLOW_WRITE_DEBUGFS */
+
+#define ccu_div_dbgfs_bit_set NULL
+#define ccu_div_dbgfs_var_clkdiv_set NULL
+#define ccu_div_dbgfs_mode 0444
+
+#endif /* !CCU_DIV_ALLOW_WRITE_DEBUGFS */
+
+static int ccu_div_dbgfs_bit_get(void *priv, u64 *val)
+{
+ const struct ccu_div_dbgfs_bit *bit = priv;
+ struct ccu_div *div = bit->div;
+ u32 data = 0;
+
+ regmap_read(div->sys_regs, div->reg_ctl, &data);
+ *val = !!(data & bit->mask);
+
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ccu_div_dbgfs_bit_fops,
+ ccu_div_dbgfs_bit_get, ccu_div_dbgfs_bit_set, "%llu\n");
+
+static int ccu_div_dbgfs_var_clkdiv_get(void *priv, u64 *val)
+{
+ struct ccu_div *div = priv;
+ u32 data = 0;
+
+ regmap_read(div->sys_regs, div->reg_ctl, &data);
+ *val = ccu_div_get(div->mask, data);
+
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ccu_div_dbgfs_var_clkdiv_fops,
+ ccu_div_dbgfs_var_clkdiv_get, ccu_div_dbgfs_var_clkdiv_set, "%llu\n");
+
+static int ccu_div_dbgfs_fixed_clkdiv_get(void *priv, u64 *val)
+{
+ struct ccu_div *div = priv;
+
+ *val = div->divider;
+
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ccu_div_dbgfs_fixed_clkdiv_fops,
+ ccu_div_dbgfs_fixed_clkdiv_get, NULL, "%llu\n");
+
+static void ccu_div_var_debug_init(struct clk_hw *hw, struct dentry *dentry)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ struct ccu_div_dbgfs_bit *bits;
+ int didx, bidx, num = 2;
+ const char *name;
+
+ num += !!(div->flags & CLK_SET_RATE_GATE) +
+ !!(div->features & CCU_DIV_RESET_DOMAIN);
+
+ bits = kcalloc(num, sizeof(*bits), GFP_KERNEL);
+ if (!bits)
+ return;
+
+ for (didx = 0, bidx = 0; bidx < CCU_DIV_DBGFS_BIT_NUM; ++bidx) {
+ name = ccu_div_bits[bidx].name;
+ if (!(div->flags & CLK_SET_RATE_GATE) &&
+ !strcmp("div_en", name)) {
+ continue;
+ }
+
+ if (!(div->features & CCU_DIV_RESET_DOMAIN) &&
+ !strcmp("div_rst", name)) {
+ continue;
+ }
+
+ bits[didx] = ccu_div_bits[bidx];
+ bits[didx].div = div;
+
+ if (div->features & CCU_DIV_LOCK_SHIFTED &&
+ !strcmp("div_lock", name)) {
+ bits[didx].mask = CCU_DIV_CTL_LOCK_SHIFTED;
+ }
+
+ debugfs_create_file_unsafe(bits[didx].name, ccu_div_dbgfs_mode,
+ dentry, &bits[didx],
+ &ccu_div_dbgfs_bit_fops);
+ ++didx;
+ }
+
+ debugfs_create_file_unsafe("div_clkdiv", ccu_div_dbgfs_mode, dentry,
+ div, &ccu_div_dbgfs_var_clkdiv_fops);
+}
+
+static void ccu_div_gate_debug_init(struct clk_hw *hw, struct dentry *dentry)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+ struct ccu_div_dbgfs_bit *bit;
+
+ bit = kmalloc(sizeof(*bit), GFP_KERNEL);
+ if (!bit)
+ return;
+
+ *bit = ccu_div_bits[0];
+ bit->div = div;
+ debugfs_create_file_unsafe(bit->name, ccu_div_dbgfs_mode, dentry, bit,
+ &ccu_div_dbgfs_bit_fops);
+
+ debugfs_create_file_unsafe("div_clkdiv", 0400, dentry, div,
+ &ccu_div_dbgfs_fixed_clkdiv_fops);
+}
+
+static void ccu_div_fixed_debug_init(struct clk_hw *hw, struct dentry *dentry)
+{
+ struct ccu_div *div = to_ccu_div(hw);
+
+ debugfs_create_file_unsafe("div_clkdiv", 0400, dentry, div,
+ &ccu_div_dbgfs_fixed_clkdiv_fops);
+}
+
+#else /* !CONFIG_DEBUG_FS */
+
+#define ccu_div_var_debug_init NULL
+#define ccu_div_gate_debug_init NULL
+#define ccu_div_fixed_debug_init NULL
+
+#endif /* !CONFIG_DEBUG_FS */
+
+static const struct clk_ops ccu_div_var_gate_to_set_ops = {
+ .enable = ccu_div_var_enable,
+ .disable = ccu_div_gate_disable,
+ .is_enabled = ccu_div_gate_is_enabled,
+ .recalc_rate = ccu_div_var_recalc_rate,
+ .round_rate = ccu_div_var_round_rate,
+ .set_rate = ccu_div_var_set_rate_fast,
+ .debug_init = ccu_div_var_debug_init
+};
+
+static const struct clk_ops ccu_div_var_nogate_ops = {
+ .recalc_rate = ccu_div_var_recalc_rate,
+ .round_rate = ccu_div_var_round_rate,
+ .set_rate = ccu_div_var_set_rate_slow,
+ .debug_init = ccu_div_var_debug_init
+};
+
+static const struct clk_ops ccu_div_gate_ops = {
+ .enable = ccu_div_gate_enable,
+ .disable = ccu_div_gate_disable,
+ .is_enabled = ccu_div_gate_is_enabled,
+ .recalc_rate = ccu_div_fixed_recalc_rate,
+ .round_rate = ccu_div_fixed_round_rate,
+ .set_rate = ccu_div_fixed_set_rate,
+ .debug_init = ccu_div_gate_debug_init
+};
+
+static const struct clk_ops ccu_div_fixed_ops = {
+ .recalc_rate = ccu_div_fixed_recalc_rate,
+ .round_rate = ccu_div_fixed_round_rate,
+ .set_rate = ccu_div_fixed_set_rate,
+ .debug_init = ccu_div_fixed_debug_init
+};
+
+struct ccu_div *ccu_div_hw_register(const struct ccu_div_init_data *div_init)
+{
+ struct clk_parent_data parent_data = { };
+ struct clk_init_data hw_init = { };
+ struct ccu_div *div;
+ int ret;
+
+ if (!div_init)
+ return ERR_PTR(-EINVAL);
+
+ div = kzalloc(sizeof(*div), GFP_KERNEL);
+ if (!div)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Note since Baikal-T1 System Controller registers are MMIO-backed
+ * we won't check the regmap IO operations return status, because it
+ * must be zero anyway.
+ */
+ div->hw.init = &hw_init;
+ div->id = div_init->id;
+ div->reg_ctl = div_init->base + CCU_DIV_CTL;
+ div->sys_regs = div_init->sys_regs;
+ div->flags = div_init->flags;
+ div->features = div_init->features;
+ spin_lock_init(&div->lock);
+
+ hw_init.name = div_init->name;
+ hw_init.flags = div_init->flags;
+
+ if (div_init->type == CCU_DIV_VAR) {
+ if (hw_init.flags & CLK_SET_RATE_GATE)
+ hw_init.ops = &ccu_div_var_gate_to_set_ops;
+ else
+ hw_init.ops = &ccu_div_var_nogate_ops;
+ div->mask = CCU_DIV_CTL_CLKDIV_MASK(div_init->width);
+ } else if (div_init->type == CCU_DIV_GATE) {
+ hw_init.ops = &ccu_div_gate_ops;
+ div->divider = div_init->divider;
+ } else if (div_init->type == CCU_DIV_FIXED) {
+ hw_init.ops = &ccu_div_fixed_ops;
+ div->divider = div_init->divider;
+ } else {
+ ret = -EINVAL;
+ goto err_free_div;
+ }
+
+ if (!div_init->parent_name) {
+ ret = -EINVAL;
+ goto err_free_div;
+ }
+ parent_data.fw_name = div_init->parent_name;
+ hw_init.parent_data = &parent_data;
+ hw_init.num_parents = 1;
+
+ ret = of_clk_hw_register(div_init->np, &div->hw);
+ if (ret)
+ goto err_free_div;
+
+ return div;
+
+err_free_div:
+ kfree(div);
+
+ return ERR_PTR(ret);
+}
+
+void ccu_div_hw_unregister(struct ccu_div *div)
+{
+ clk_hw_unregister(&div->hw);
+
+ kfree(div);
+}
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
+ *
+ * Baikal-T1 CCU Dividers interface driver
+ */
+#ifndef __CLK_BT1_CCU_DIV_H__
+#define __CLK_BT1_CCU_DIV_H__
+
+#include <linux/clk-provider.h>
+#include <linux/spinlock.h>
+#include <linux/regmap.h>
+#include <linux/bits.h>
+#include <linux/of.h>
+
+/*
+ * CCU Divider private flags
+ * @CCU_DIV_SKIP_ONE: Due to some reason divider can't be set to 1.
+ * It can be 0 though, which is functionally the same.
+ * @CCU_DIV_SKIP_ONE_TO_THREE: For some reason divider can't be within [1,3].
+ * It can be either 0 or greater than 3.
+ * @CCU_DIV_LOCK_SHIFTED: Find lock-bit at non-standard position.
+ * @CCU_DIV_RESET_DOMAIN: Provide reset clock domain method.
+ */
+#define CCU_DIV_SKIP_ONE BIT(1)
+#define CCU_DIV_SKIP_ONE_TO_THREE BIT(2)
+#define CCU_DIV_LOCK_SHIFTED BIT(3)
+#define CCU_DIV_RESET_DOMAIN BIT(4)
+
+/*
+ * enum ccu_div_type - CCU Divider types
+ * @CCU_DIV_VAR: Clocks gate with variable divider.
+ * @CCU_DIV_GATE: Clocks gate with fixed divider.
+ * @CCU_DIV_FIXED: Ungateable clock with fixed divider.
+ */
+enum ccu_div_type {
+ CCU_DIV_VAR,
+ CCU_DIV_GATE,
+ CCU_DIV_FIXED
+};
+
+/*
+ * struct ccu_div_init_data - CCU Divider initialization data
+ * @id: Clocks private identifier.
+ * @name: Clocks name.
+ * @parent_name: Parent clocks name in a fw node.
+ * @base: Divider register base address with respect to the sys_regs base.
+ * @sys_regs: Baikal-T1 System Controller registers map.
+ * @np: Pointer to the node describing the CCU Dividers.
+ * @type: CCU divider type (variable, fixed with and without gate).
+ * @width: Divider width if it's variable.
+ * @divider: Divider fixed value.
+ * @flags: CCU Divider clock flags.
+ * @features: CCU Divider private features.
+ */
+struct ccu_div_init_data {
+ unsigned int id;
+ const char *name;
+ const char *parent_name;
+ unsigned int base;
+ struct regmap *sys_regs;
+ struct device_node *np;
+ enum ccu_div_type type;
+ union {
+ unsigned int width;
+ unsigned int divider;
+ };
+ unsigned long flags;
+ unsigned long features;
+};
+
+/*
+ * struct ccu_div - CCU Divider descriptor
+ * @hw: clk_hw of the divider.
+ * @id: Clock private identifier.
+ * @reg_ctl: Divider control register base address.
+ * @sys_regs: Baikal-T1 System Controller registers map.
+ * @lock: Divider state change spin-lock.
+ * @mask: Divider field mask.
+ * @divider: Divider fixed value.
+ * @flags: Divider clock flags.
+ * @features: CCU Divider private features.
+ */
+struct ccu_div {
+ struct clk_hw hw;
+ unsigned int id;
+ unsigned int reg_ctl;
+ struct regmap *sys_regs;
+ spinlock_t lock;
+ union {
+ u32 mask;
+ unsigned int divider;
+ };
+ unsigned long flags;
+ unsigned long features;
+};
+#define to_ccu_div(_hw) container_of(_hw, struct ccu_div, hw)
+
+static inline struct clk_hw *ccu_div_get_clk_hw(struct ccu_div *div)
+{
+ return div ? &div->hw : NULL;
+}
+
+struct ccu_div *ccu_div_hw_register(const struct ccu_div_init_data *init);
+
+void ccu_div_hw_unregister(struct ccu_div *div);
+
+int ccu_div_reset_domain(struct ccu_div *div);
+
+#endif /* __CLK_BT1_CCU_DIV_H__ */
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
+ *
+ * Authors:
+ * Serge Semin <Sergey.Semin@baikalelectronics.ru>
+ * Dmitry Dunaev <dmitry.dunaev@baikalelectronics.ru>
+ *
+ * Baikal-T1 CCU Dividers clock driver
+ */
+
+#define pr_fmt(fmt) "bt1-ccu-div: " fmt
+
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/clk-provider.h>
+#include <linux/reset-controller.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/ioport.h>
+#include <linux/regmap.h>
+
+#include <dt-bindings/clock/bt1-ccu.h>
+#include <dt-bindings/reset/bt1-ccu.h>
+
+#include "ccu-div.h"
+
+#define CCU_AXI_MAIN_BASE 0x030
+#define CCU_AXI_DDR_BASE 0x034
+#define CCU_AXI_SATA_BASE 0x038
+#define CCU_AXI_GMAC0_BASE 0x03C
+#define CCU_AXI_GMAC1_BASE 0x040
+#define CCU_AXI_XGMAC_BASE 0x044
+#define CCU_AXI_PCIE_M_BASE 0x048
+#define CCU_AXI_PCIE_S_BASE 0x04C
+#define CCU_AXI_USB_BASE 0x050
+#define CCU_AXI_HWA_BASE 0x054
+#define CCU_AXI_SRAM_BASE 0x058
+
+#define CCU_SYS_SATA_REF_BASE 0x060
+#define CCU_SYS_APB_BASE 0x064
+#define CCU_SYS_GMAC0_BASE 0x068
+#define CCU_SYS_GMAC1_BASE 0x06C
+#define CCU_SYS_XGMAC_BASE 0x070
+#define CCU_SYS_USB_BASE 0x074
+#define CCU_SYS_PVT_BASE 0x078
+#define CCU_SYS_HWA_BASE 0x07C
+#define CCU_SYS_UART_BASE 0x084
+#define CCU_SYS_TIMER0_BASE 0x088
+#define CCU_SYS_TIMER1_BASE 0x08C
+#define CCU_SYS_TIMER2_BASE 0x090
+#define CCU_SYS_WDT_BASE 0x150
+
+#define CCU_DIV_VAR_INFO(_id, _name, _pname, _base, _width, _flags, _features) \
+ { \
+ .id = _id, \
+ .name = _name, \
+ .parent_name = _pname, \
+ .base = _base, \
+ .type = CCU_DIV_VAR, \
+ .width = _width, \
+ .flags = _flags, \
+ .features = _features \
+ }
+
+#define CCU_DIV_GATE_INFO(_id, _name, _pname, _base, _divider) \
+ { \
+ .id = _id, \
+ .name = _name, \
+ .parent_name = _pname, \
+ .base = _base, \
+ .type = CCU_DIV_GATE, \
+ .divider = _divider \
+ }
+
+#define CCU_DIV_FIXED_INFO(_id, _name, _pname, _divider) \
+ { \
+ .id = _id, \
+ .name = _name, \
+ .parent_name = _pname, \
+ .type = CCU_DIV_FIXED, \
+ .divider = _divider \
+ }
+
+#define CCU_DIV_RST_MAP(_rst_id, _clk_id) \
+ { \
+ .rst_id = _rst_id, \
+ .clk_id = _clk_id \
+ }
+
+struct ccu_div_info {
+ unsigned int id;
+ const char *name;
+ const char *parent_name;
+ unsigned int base;
+ enum ccu_div_type type;
+ union {
+ unsigned int width;
+ unsigned int divider;
+ };
+ unsigned long flags;
+ unsigned long features;
+};
+
+struct ccu_div_rst_map {
+ unsigned int rst_id;
+ unsigned int clk_id;
+};
+
+struct ccu_div_data {
+ struct device_node *np;
+ struct regmap *sys_regs;
+
+ unsigned int divs_num;
+ const struct ccu_div_info *divs_info;
+ struct ccu_div **divs;
+
+ unsigned int rst_num;
+ const struct ccu_div_rst_map *rst_map;
+ struct reset_controller_dev rcdev;
+};
+#define to_ccu_div_data(_rcdev) container_of(_rcdev, struct ccu_div_data, rcdev)
+
+/*
+ * AXI Main Interconnect (axi_main_clk) and DDR AXI-bus (axi_ddr_clk) clocks
+ * must be left enabled in any case, since former one is responsible for
+ * clocking a bus between CPU cores and the rest of the SoC components, while
+ * the later is clocking the AXI-bus between DDR controller and the Main
+ * Interconnect. So should any of these clocks get to be disabled, the system
+ * will literally stop working. That's why we marked them as critical.
+ */
+static const struct ccu_div_info axi_info[] = {
+ CCU_DIV_VAR_INFO(CCU_AXI_MAIN_CLK, "axi_main_clk", "pcie_clk",
+ CCU_AXI_MAIN_BASE, 4,
+ CLK_IS_CRITICAL, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_DDR_CLK, "axi_ddr_clk", "sata_clk",
+ CCU_AXI_DDR_BASE, 4,
+ CLK_IS_CRITICAL | CLK_SET_RATE_GATE,
+ CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_SATA_CLK, "axi_sata_clk", "sata_clk",
+ CCU_AXI_SATA_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_GMAC0_CLK, "axi_gmac0_clk", "eth_clk",
+ CCU_AXI_GMAC0_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_GMAC1_CLK, "axi_gmac1_clk", "eth_clk",
+ CCU_AXI_GMAC1_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_XGMAC_CLK, "axi_xgmac_clk", "eth_clk",
+ CCU_AXI_XGMAC_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_PCIE_M_CLK, "axi_pcie_m_clk", "pcie_clk",
+ CCU_AXI_PCIE_M_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_PCIE_S_CLK, "axi_pcie_s_clk", "pcie_clk",
+ CCU_AXI_PCIE_S_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_USB_CLK, "axi_usb_clk", "sata_clk",
+ CCU_AXI_USB_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_HWA_CLK, "axi_hwa_clk", "sata_clk",
+ CCU_AXI_HWA_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_AXI_SRAM_CLK, "axi_sram_clk", "eth_clk",
+ CCU_AXI_SRAM_BASE, 4,
+ CLK_SET_RATE_GATE, CCU_DIV_RESET_DOMAIN)
+};
+
+static const struct ccu_div_rst_map axi_rst_map[] = {
+ CCU_DIV_RST_MAP(CCU_AXI_MAIN_RST, CCU_AXI_MAIN_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_DDR_RST, CCU_AXI_DDR_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_SATA_RST, CCU_AXI_SATA_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_GMAC0_RST, CCU_AXI_GMAC0_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_GMAC1_RST, CCU_AXI_GMAC1_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_XGMAC_RST, CCU_AXI_XGMAC_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_PCIE_M_RST, CCU_AXI_PCIE_M_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_PCIE_S_RST, CCU_AXI_PCIE_S_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_USB_RST, CCU_AXI_USB_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_HWA_RST, CCU_AXI_HWA_CLK),
+ CCU_DIV_RST_MAP(CCU_AXI_SRAM_RST, CCU_AXI_SRAM_CLK)
+};
+
+/*
+ * APB-bus clock is marked as critical since it's a main communication bus
+ * for the SoC devices registers IO-operations.
+ */
+static const struct ccu_div_info sys_info[] = {
+ CCU_DIV_VAR_INFO(CCU_SYS_SATA_REF_CLK, "sys_sata_ref_clk",
+ "sata_clk", CCU_SYS_SATA_REF_BASE, 4,
+ CLK_SET_RATE_GATE,
+ CCU_DIV_SKIP_ONE | CCU_DIV_LOCK_SHIFTED |
+ CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_VAR_INFO(CCU_SYS_APB_CLK, "sys_apb_clk",
+ "pcie_clk", CCU_SYS_APB_BASE, 5,
+ CLK_IS_CRITICAL, CCU_DIV_RESET_DOMAIN),
+ CCU_DIV_GATE_INFO(CCU_SYS_GMAC0_TX_CLK, "sys_gmac0_tx_clk",
+ "eth_clk", CCU_SYS_GMAC0_BASE, 5),
+ CCU_DIV_FIXED_INFO(CCU_SYS_GMAC0_PTP_CLK, "sys_gmac0_ptp_clk",
+ "eth_clk", 10),
+ CCU_DIV_GATE_INFO(CCU_SYS_GMAC1_TX_CLK, "sys_gmac1_tx_clk",
+ "eth_clk", CCU_SYS_GMAC1_BASE, 5),
+ CCU_DIV_FIXED_INFO(CCU_SYS_GMAC1_PTP_CLK, "sys_gmac1_ptp_clk",
+ "eth_clk", 10),
+ CCU_DIV_GATE_INFO(CCU_SYS_XGMAC_REF_CLK, "sys_xgmac_ref_clk",
+ "eth_clk", CCU_SYS_XGMAC_BASE, 8),
+ CCU_DIV_FIXED_INFO(CCU_SYS_XGMAC_PTP_CLK, "sys_xgmac_ptp_clk",
+ "eth_clk", 10),
+ CCU_DIV_GATE_INFO(CCU_SYS_USB_CLK, "sys_usb_clk",
+ "eth_clk", CCU_SYS_USB_BASE, 10),
+ CCU_DIV_VAR_INFO(CCU_SYS_PVT_CLK, "sys_pvt_clk",
+ "ref_clk", CCU_SYS_PVT_BASE, 5,
+ CLK_SET_RATE_GATE, 0),
+ CCU_DIV_VAR_INFO(CCU_SYS_HWA_CLK, "sys_hwa_clk",
+ "sata_clk", CCU_SYS_HWA_BASE, 4,
+ CLK_SET_RATE_GATE, 0),
+ CCU_DIV_VAR_INFO(CCU_SYS_UART_CLK, "sys_uart_clk",
+ "eth_clk", CCU_SYS_UART_BASE, 17,
+ CLK_SET_RATE_GATE, 0),
+ CCU_DIV_FIXED_INFO(CCU_SYS_I2C1_CLK, "sys_i2c1_clk",
+ "eth_clk", 10),
+ CCU_DIV_FIXED_INFO(CCU_SYS_I2C2_CLK, "sys_i2c2_clk",
+ "eth_clk", 10),
+ CCU_DIV_FIXED_INFO(CCU_SYS_GPIO_CLK, "sys_gpio_clk",
+ "ref_clk", 25),
+ CCU_DIV_VAR_INFO(CCU_SYS_TIMER0_CLK, "sys_timer0_clk",
+ "ref_clk", CCU_SYS_TIMER0_BASE, 17,
+ CLK_SET_RATE_GATE, 0),
+ CCU_DIV_VAR_INFO(CCU_SYS_TIMER1_CLK, "sys_timer1_clk",
+ "ref_clk", CCU_SYS_TIMER1_BASE, 17,
+ CLK_SET_RATE_GATE, 0),
+ CCU_DIV_VAR_INFO(CCU_SYS_TIMER2_CLK, "sys_timer2_clk",
+ "ref_clk", CCU_SYS_TIMER2_BASE, 17,
+ CLK_SET_RATE_GATE, 0),
+ CCU_DIV_VAR_INFO(CCU_SYS_WDT_CLK, "sys_wdt_clk",
+ "eth_clk", CCU_SYS_WDT_BASE, 17,
+ CLK_SET_RATE_GATE, CCU_DIV_SKIP_ONE_TO_THREE)
+};
+
+static const struct ccu_div_rst_map sys_rst_map[] = {
+ CCU_DIV_RST_MAP(CCU_SYS_SATA_REF_RST, CCU_SYS_SATA_REF_CLK),
+ CCU_DIV_RST_MAP(CCU_SYS_APB_RST, CCU_SYS_APB_CLK),
+};
+
+static struct ccu_div *ccu_div_find_desc(struct ccu_div_data *data,
+ unsigned int clk_id)
+{
+ struct ccu_div *div;
+ int idx;
+
+ for (idx = 0; idx < data->divs_num; ++idx) {
+ div = data->divs[idx];
+ if (div && div->id == clk_id)
+ return div;
+ }
+
+ return ERR_PTR(-EINVAL);
+}
+
+static int ccu_div_reset(struct reset_controller_dev *rcdev,
+ unsigned long rst_id)
+{
+ struct ccu_div_data *data = to_ccu_div_data(rcdev);
+ const struct ccu_div_rst_map *map;
+ struct ccu_div *div;
+ int idx, ret;
+
+ for (idx = 0, map = data->rst_map; idx < data->rst_num; ++idx, ++map) {
+ if (map->rst_id == rst_id)
+ break;
+ }
+ if (idx == data->rst_num) {
+ pr_err("Invalid reset ID %lu specified\n", rst_id);
+ return -EINVAL;
+ }
+
+ div = ccu_div_find_desc(data, map->clk_id);
+ if (IS_ERR(div)) {
+ pr_err("Invalid clock ID %d in mapping\n", map->clk_id);
+ return PTR_ERR(div);
+ }
+
+ ret = ccu_div_reset_domain(div);
+ if (ret) {
+ pr_err("Reset isn't supported by divider %s\n",
+ clk_hw_get_name(ccu_div_get_clk_hw(div)));
+ }
+
+ return ret;
+}
+
+static const struct reset_control_ops ccu_div_rst_ops = {
+ .reset = ccu_div_reset,
+};
+
+static struct ccu_div_data *ccu_div_create_data(struct device_node *np)
+{
+ struct ccu_div_data *data;
+ int ret;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return ERR_PTR(-ENOMEM);
+
+ data->np = np;
+ if (of_device_is_compatible(np, "baikal,bt1-ccu-axi")) {
+ data->divs_num = ARRAY_SIZE(axi_info);
+ data->divs_info = axi_info;
+ data->rst_num = ARRAY_SIZE(axi_rst_map);
+ data->rst_map = axi_rst_map;
+ } else if (of_device_is_compatible(np, "baikal,bt1-ccu-sys")) {
+ data->divs_num = ARRAY_SIZE(sys_info);
+ data->divs_info = sys_info;
+ data->rst_num = ARRAY_SIZE(sys_rst_map);
+ data->rst_map = sys_rst_map;
+ } else {
+ pr_err("Uncompatible DT node '%s' specified\n",
+ of_node_full_name(np));
+ ret = -EINVAL;
+ goto err_kfree_data;
+ }
+
+ data->divs = kcalloc(data->divs_num, sizeof(*data->divs), GFP_KERNEL);
+ if (!data->divs) {
+ ret = -ENOMEM;
+ goto err_kfree_data;
+ }
+
+ return data;
+
+err_kfree_data:
+ kfree(data);
+
+ return ERR_PTR(ret);
+}
+
+static void ccu_div_free_data(struct ccu_div_data *data)
+{
+ kfree(data->divs);
+
+ kfree(data);
+}
+
+static int ccu_div_find_sys_regs(struct ccu_div_data *data)
+{
+ data->sys_regs = syscon_node_to_regmap(data->np->parent);
+ if (IS_ERR(data->sys_regs)) {
+ pr_err("Failed to find syscon regs for '%s'\n",
+ of_node_full_name(data->np));
+ return PTR_ERR(data->sys_regs);
+ }
+
+ return 0;
+}
+
+static struct clk_hw *ccu_div_of_clk_hw_get(struct of_phandle_args *clkspec,
+ void *priv)
+{
+ struct ccu_div_data *data = priv;
+ struct ccu_div *div;
+ unsigned int clk_id;
+
+ clk_id = clkspec->args[0];
+ div = ccu_div_find_desc(data, clk_id);
+ if (IS_ERR(div)) {
+ pr_info("Invalid clock ID %d specified\n", clk_id);
+ return ERR_CAST(div);
+ }
+
+ return ccu_div_get_clk_hw(div);
+}
+
+static int ccu_div_clk_register(struct ccu_div_data *data)
+{
+ int idx, ret;
+
+ for (idx = 0; idx < data->divs_num; ++idx) {
+ const struct ccu_div_info *info = &data->divs_info[idx];
+ struct ccu_div_init_data init = {0};
+
+ init.id = info->id;
+ init.name = info->name;
+ init.parent_name = info->parent_name;
+ init.np = data->np;
+ init.type = info->type;
+ init.flags = info->flags;
+ init.features = info->features;
+
+ if (init.type == CCU_DIV_VAR) {
+ init.base = info->base;
+ init.sys_regs = data->sys_regs;
+ init.width = info->width;
+ } else if (init.type == CCU_DIV_GATE) {
+ init.base = info->base;
+ init.sys_regs = data->sys_regs;
+ init.divider = info->divider;
+ } else {
+ init.divider = info->divider;
+ }
+
+ data->divs[idx] = ccu_div_hw_register(&init);
+ if (IS_ERR(data->divs[idx])) {
+ ret = PTR_ERR(data->divs[idx]);
+ pr_err("Couldn't register divider '%s' hw\n",
+ init.name);
+ goto err_hw_unregister;
+ }
+ }
+
+ ret = of_clk_add_hw_provider(data->np, ccu_div_of_clk_hw_get, data);
+ if (ret) {
+ pr_err("Couldn't register dividers '%s' clock provider\n",
+ of_node_full_name(data->np));
+ goto err_hw_unregister;
+ }
+
+ return 0;
+
+err_hw_unregister:
+ for (--idx; idx >= 0; --idx)
+ ccu_div_hw_unregister(data->divs[idx]);
+
+ return ret;
+}
+
+static void ccu_div_clk_unregister(struct ccu_div_data *data)
+{
+ int idx;
+
+ of_clk_del_provider(data->np);
+
+ for (idx = 0; idx < data->divs_num; ++idx)
+ ccu_div_hw_unregister(data->divs[idx]);
+}
+
+static int ccu_div_rst_register(struct ccu_div_data *data)
+{
+ int ret;
+
+ data->rcdev.ops = &ccu_div_rst_ops;
+ data->rcdev.of_node = data->np;
+ data->rcdev.nr_resets = data->rst_num;
+
+ ret = reset_controller_register(&data->rcdev);
+ if (ret)
+ pr_err("Couldn't register divider '%s' reset controller\n",
+ of_node_full_name(data->np));
+
+ return ret;
+}
+
+static void ccu_div_init(struct device_node *np)
+{
+ struct ccu_div_data *data;
+ int ret;
+
+ data = ccu_div_create_data(np);
+ if (IS_ERR(data))
+ return;
+
+ ret = ccu_div_find_sys_regs(data);
+ if (ret)
+ goto err_free_data;
+
+ ret = ccu_div_clk_register(data);
+ if (ret)
+ goto err_free_data;
+
+ ret = ccu_div_rst_register(data);
+ if (ret)
+ goto err_clk_unregister;
+
+ return;
+
+err_clk_unregister:
+ ccu_div_clk_unregister(data);
+
+err_free_data:
+ ccu_div_free_data(data);
+}
+
+CLK_OF_DECLARE(ccu_axi, "baikal,bt1-ccu-axi", ccu_div_init);
+CLK_OF_DECLARE(ccu_sys, "baikal,bt1-ccu-sys", ccu_div_init);
projects / kernel.git / commitdiff