[PATCH v14 05/13] clk: ingenic: Add driver for the TCU clocks

From: Paul Cercueil
Date: Mon Jul 01 2019 - 11:14:33 EST

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Add driver to support the clocks provided by the Timer/Counter Unit
(TCU) of the JZ47xx SoCs from Ingenic.

Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Tested-by: Mathieu Malaterre <malat@xxxxxxxxxx>
Tested-by: Artur Rojek <contact@xxxxxxxxxxxxxx>
---

Notes:
v12: New patch

v13:
- Don't enable/disable the TCU clock on demand. Enable it in the probe
and call it a day.
- Register suspend callbacks to gate/ungate the TCU clock on
suspend/resume.
- Use pr_fmt and pr_crit instead of custom TCU_ERR() macro
- Remove useless dependency on COMMON_CLK in Kconfig
- Remove registration of clkdev

v14: Change %i to %d

drivers/clk/ingenic/Kconfig | 10 +-
drivers/clk/ingenic/Makefile | 1 +
drivers/clk/ingenic/tcu.c | 473 +++++++++++++++++++++++++++++++++++
3 files changed, 483 insertions(+), 1 deletion(-)
create mode 100644 drivers/clk/ingenic/tcu.c

diff --git a/drivers/clk/ingenic/Kconfig b/drivers/clk/ingenic/Kconfig
index fe8db93cf21a..0f39c038670f 100644
--- a/drivers/clk/ingenic/Kconfig
+++ b/drivers/clk/ingenic/Kconfig
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
-menu "Ingenic JZ47xx CGU drivers"
+menu "Ingenic JZ47xx drivers"
depends on MIPS

config INGENIC_CGU_COMMON
@@ -45,4 +45,12 @@ config INGENIC_CGU_JZ4780

If building for a JZ4780 SoC, you want to say Y here.

+config INGENIC_TCU_CLK
+ bool "Ingenic JZ47xx TCU clocks driver"
+ default MACH_INGENIC
+ select INGENIC_TCU
+ help
+ Support the clocks of the Timer/Counter Unit (TCU) of the Ingenic
+ JZ47xx SoCs.
+
endmenu
diff --git a/drivers/clk/ingenic/Makefile b/drivers/clk/ingenic/Makefile
index ab58a6a862a5..d25a5801bd8a 100644
--- a/drivers/clk/ingenic/Makefile
+++ b/drivers/clk/ingenic/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_INGENIC_CGU_JZ4740) += jz4740-cgu.o
obj-$(CONFIG_INGENIC_CGU_JZ4725B) += jz4725b-cgu.o
obj-$(CONFIG_INGENIC_CGU_JZ4770) += jz4770-cgu.o
obj-$(CONFIG_INGENIC_CGU_JZ4780) += jz4780-cgu.o
+obj-$(CONFIG_INGENIC_TCU_CLK) += tcu.o
diff --git a/drivers/clk/ingenic/tcu.c b/drivers/clk/ingenic/tcu.c
new file mode 100644
index 000000000000..528aa215eb0f
--- /dev/null
+++ b/drivers/clk/ingenic/tcu.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ47xx SoCs TCU clocks driver
+ * Copyright (C) 2019 Paul Cercueil <paul@xxxxxxxxxxxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clockchips.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/syscore_ops.h>
+
+#include <dt-bindings/clock/ingenic,tcu.h>
+
+/* 8 channels max + watchdog + OST */
+#define TCU_CLK_COUNT 10
+
+#undef pr_fmt
+#define pr_fmt(fmt) "ingenic-tcu-clk: " fmt
+
+enum tcu_clk_parent {
+ TCU_PARENT_PCLK,
+ TCU_PARENT_RTC,
+ TCU_PARENT_EXT,
+};
+
+struct ingenic_soc_info {
+ unsigned int num_channels;
+ bool has_ost;
+ bool has_tcu_clk;
+};
+
+struct ingenic_tcu_clk_info {
+ struct clk_init_data init_data;
+ u8 gate_bit;
+ u8 tcsr_reg;
+};
+
+struct ingenic_tcu_clk {
+ struct clk_hw hw;
+ unsigned int idx;
+ struct ingenic_tcu *tcu;
+ const struct ingenic_tcu_clk_info *info;
+};
+
+struct ingenic_tcu {
+ const struct ingenic_soc_info *soc_info;
+ struct regmap *map;
+ struct clk *clk;
+
+ struct clk_hw_onecell_data *clocks;
+};
+
+static struct ingenic_tcu *ingenic_tcu;
+
+static inline struct ingenic_tcu_clk *to_tcu_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct ingenic_tcu_clk, hw);
+}
+
+static int ingenic_tcu_enable(struct clk_hw *hw)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ struct ingenic_tcu *tcu = tcu_clk->tcu;
+
+ regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
+
+ return 0;
+}
+
+static void ingenic_tcu_disable(struct clk_hw *hw)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ struct ingenic_tcu *tcu = tcu_clk->tcu;
+
+ regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
+}
+
+static int ingenic_tcu_is_enabled(struct clk_hw *hw)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ unsigned int value;
+
+ regmap_read(tcu_clk->tcu->map, TCU_REG_TSR, &value);
+
+ return !(value & BIT(info->gate_bit));
+}
+
+static bool ingenic_tcu_enable_regs(struct clk_hw *hw)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ struct ingenic_tcu *tcu = tcu_clk->tcu;
+ bool enabled = false;
+
+ /*
+ * If the SoC has no global TCU clock, we must ungate the channel's
+ * clock to be able to access its registers.
+ * If we have a TCU clock, it will be enabled automatically as it has
+ * been attached to the regmap.
+ */
+ if (!tcu->clk) {
+ enabled = !!ingenic_tcu_is_enabled(hw);
+ regmap_write(tcu->map, TCU_REG_TSCR, BIT(info->gate_bit));
+ }
+
+ return enabled;
+}
+
+static void ingenic_tcu_disable_regs(struct clk_hw *hw)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ struct ingenic_tcu *tcu = tcu_clk->tcu;
+
+ if (!tcu->clk)
+ regmap_write(tcu->map, TCU_REG_TSSR, BIT(info->gate_bit));
+}
+
+static u8 ingenic_tcu_get_parent(struct clk_hw *hw)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ unsigned int val = 0;
+ int ret;
+
+ ret = regmap_read(tcu_clk->tcu->map, info->tcsr_reg, &val);
+ WARN_ONCE(ret < 0, "Unable to read TCSR %d", tcu_clk->idx);
+
+ return ffs(val & TCU_TCSR_PARENT_CLOCK_MASK) - 1;
+}
+
+static int ingenic_tcu_set_parent(struct clk_hw *hw, u8 idx)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ bool was_enabled;
+ int ret;
+
+ was_enabled = ingenic_tcu_enable_regs(hw);
+
+ ret = regmap_update_bits(tcu_clk->tcu->map, info->tcsr_reg,
+ TCU_TCSR_PARENT_CLOCK_MASK, BIT(idx));
+ WARN_ONCE(ret < 0, "Unable to update TCSR %d", tcu_clk->idx);
+
+ if (!was_enabled)
+ ingenic_tcu_disable_regs(hw);
+
+ return 0;
+}
+
+static unsigned long ingenic_tcu_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ unsigned int prescale;
+ int ret;
+
+ ret = regmap_read(tcu_clk->tcu->map, info->tcsr_reg, &prescale);
+ WARN_ONCE(ret < 0, "Unable to read TCSR %d", tcu_clk->idx);
+
+ prescale = (prescale & TCU_TCSR_PRESCALE_MASK) >> TCU_TCSR_PRESCALE_LSB;
+
+ return parent_rate >> (prescale * 2);
+}
+
+static u8 ingenic_tcu_get_prescale(unsigned long rate, unsigned long req_rate)
+{
+ u8 prescale;
+
+ for (prescale = 0; prescale < 5; prescale++)
+ if ((rate >> (prescale * 2)) <= req_rate)
+ return prescale;
+
+ return 5; /* /1024 divider */
+}
+
+static long ingenic_tcu_round_rate(struct clk_hw *hw, unsigned long req_rate,
+ unsigned long *parent_rate)
+{
+ unsigned long rate = *parent_rate;
+ u8 prescale;
+
+ if (req_rate > rate)
+ return -EINVAL;
+
+ prescale = ingenic_tcu_get_prescale(rate, req_rate);
+
+ return rate >> (prescale * 2);
+}
+
+static int ingenic_tcu_set_rate(struct clk_hw *hw, unsigned long req_rate,
+ unsigned long parent_rate)
+{
+ struct ingenic_tcu_clk *tcu_clk = to_tcu_clk(hw);
+ const struct ingenic_tcu_clk_info *info = tcu_clk->info;
+ u8 prescale = ingenic_tcu_get_prescale(parent_rate, req_rate);
+ bool was_enabled;
+ int ret;
+
+ was_enabled = ingenic_tcu_enable_regs(hw);
+
+ ret = regmap_update_bits(tcu_clk->tcu->map, info->tcsr_reg,
+ TCU_TCSR_PRESCALE_MASK,
+ prescale << TCU_TCSR_PRESCALE_LSB);
+ WARN_ONCE(ret < 0, "Unable to update TCSR %d", tcu_clk->idx);
+
+ if (!was_enabled)
+ ingenic_tcu_disable_regs(hw);
+
+ return 0;
+}
+
+static const struct clk_ops ingenic_tcu_clk_ops = {
+ .get_parent = ingenic_tcu_get_parent,
+ .set_parent = ingenic_tcu_set_parent,
+
+ .recalc_rate = ingenic_tcu_recalc_rate,
+ .round_rate = ingenic_tcu_round_rate,
+ .set_rate = ingenic_tcu_set_rate,
+
+ .enable = ingenic_tcu_enable,
+ .disable = ingenic_tcu_disable,
+ .is_enabled = ingenic_tcu_is_enabled,
+};
+
+static const char * const ingenic_tcu_timer_parents[] = {
+ [TCU_PARENT_PCLK] = "pclk",
+ [TCU_PARENT_RTC] = "rtc",
+ [TCU_PARENT_EXT] = "ext",
+};
+
+#define DEF_TIMER(_name, _gate_bit, _tcsr) \
+ { \
+ .init_data = { \
+ .name = _name, \
+ .parent_names = ingenic_tcu_timer_parents, \
+ .num_parents = ARRAY_SIZE(ingenic_tcu_timer_parents),\
+ .ops = &ingenic_tcu_clk_ops, \
+ .flags = CLK_SET_RATE_UNGATE, \
+ }, \
+ .gate_bit = _gate_bit, \
+ .tcsr_reg = _tcsr, \
+ }
+static const struct ingenic_tcu_clk_info ingenic_tcu_clk_info[] = {
+ [TCU_CLK_TIMER0] = DEF_TIMER("timer0", 0, TCU_REG_TCSRc(0)),
+ [TCU_CLK_TIMER1] = DEF_TIMER("timer1", 1, TCU_REG_TCSRc(1)),
+ [TCU_CLK_TIMER2] = DEF_TIMER("timer2", 2, TCU_REG_TCSRc(2)),
+ [TCU_CLK_TIMER3] = DEF_TIMER("timer3", 3, TCU_REG_TCSRc(3)),
+ [TCU_CLK_TIMER4] = DEF_TIMER("timer4", 4, TCU_REG_TCSRc(4)),
+ [TCU_CLK_TIMER5] = DEF_TIMER("timer5", 5, TCU_REG_TCSRc(5)),
+ [TCU_CLK_TIMER6] = DEF_TIMER("timer6", 6, TCU_REG_TCSRc(6)),
+ [TCU_CLK_TIMER7] = DEF_TIMER("timer7", 7, TCU_REG_TCSRc(7)),
+};
+
+static const struct ingenic_tcu_clk_info ingenic_tcu_watchdog_clk_info =
+ DEF_TIMER("wdt", 16, TCU_REG_WDT_TCSR);
+static const struct ingenic_tcu_clk_info ingenic_tcu_ost_clk_info =
+ DEF_TIMER("ost", 15, TCU_REG_OST_TCSR);
+#undef DEF_TIMER
+
+static int __init ingenic_tcu_register_clock(struct ingenic_tcu *tcu,
+ unsigned int idx, enum tcu_clk_parent parent,
+ const struct ingenic_tcu_clk_info *info,
+ struct clk_hw_onecell_data *clocks)
+{
+ struct ingenic_tcu_clk *tcu_clk;
+ int err;
+
+ tcu_clk = kzalloc(sizeof(*tcu_clk), GFP_KERNEL);
+ if (!tcu_clk)
+ return -ENOMEM;
+
+ tcu_clk->hw.init = &info->init_data;
+ tcu_clk->idx = idx;
+ tcu_clk->info = info;
+ tcu_clk->tcu = tcu;
+
+ /* Reset channel and clock divider, set default parent */
+ ingenic_tcu_enable_regs(&tcu_clk->hw);
+ regmap_update_bits(tcu->map, info->tcsr_reg, 0xffff, BIT(parent));
+ ingenic_tcu_disable_regs(&tcu_clk->hw);
+
+ err = clk_hw_register(NULL, &tcu_clk->hw);
+ if (err) {
+ kfree(tcu_clk);
+ return err;
+ }
+
+ clocks->hws[idx] = &tcu_clk->hw;
+
+ return 0;
+}
+
+static const struct ingenic_soc_info jz4740_soc_info = {
+ .num_channels = 8,
+ .has_ost = false,
+ .has_tcu_clk = true,
+};
+
+static const struct ingenic_soc_info jz4725b_soc_info = {
+ .num_channels = 6,
+ .has_ost = true,
+ .has_tcu_clk = true,
+};
+
+static const struct ingenic_soc_info jz4770_soc_info = {
+ .num_channels = 8,
+ .has_ost = true,
+ .has_tcu_clk = false,
+};
+
+static const struct of_device_id ingenic_tcu_of_match[] __initconst = {
+ { .compatible = "ingenic,jz4740-tcu", .data = &jz4740_soc_info, },
+ { .compatible = "ingenic,jz4725b-tcu", .data = &jz4725b_soc_info, },
+ { .compatible = "ingenic,jz4770-tcu", .data = &jz4770_soc_info, },
+ { }
+};
+
+static int __init ingenic_tcu_probe(struct device_node *np)
+{
+ const struct of_device_id *id = of_match_node(ingenic_tcu_of_match, np);
+ struct ingenic_tcu *tcu;
+ struct regmap *map;
+ unsigned int i;
+ int ret;
+
+ map = ingenic_tcu_get_regmap(np);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
+ if (!tcu)
+ return -ENOMEM;
+
+ tcu->map = map;
+ tcu->soc_info = id->data;
+
+ if (tcu->soc_info->has_tcu_clk) {
+ tcu->clk = of_clk_get_by_name(np, "tcu");
+ if (IS_ERR(tcu->clk)) {
+ ret = PTR_ERR(tcu->clk);
+ pr_crit("Cannot get TCU clock\n");
+ goto err_free_tcu;
+ }
+
+ ret = clk_prepare_enable(tcu->clk);
+ if (ret) {
+ pr_crit("Unable to enable TCU clock\n");
+ goto err_put_clk;
+ }
+ }
+
+ tcu->clocks = kzalloc(sizeof(*tcu->clocks) +
+ sizeof(*tcu->clocks->hws) * TCU_CLK_COUNT,
+ GFP_KERNEL);
+ if (!tcu->clocks) {
+ ret = -ENOMEM;
+ goto err_clk_disable;
+ }
+
+ tcu->clocks->num = TCU_CLK_COUNT;
+
+ for (i = 0; i < tcu->soc_info->num_channels; i++) {
+ ret = ingenic_tcu_register_clock(tcu, i, TCU_PARENT_EXT,
+ &ingenic_tcu_clk_info[i],
+ tcu->clocks);
+ if (ret) {
+ pr_crit("cannot register clock %d\n", i);
+ goto err_unregister_timer_clocks;
+ }
+ }
+
+ /*
+ * We set EXT as the default parent clock for all the TCU clocks
+ * except for the watchdog one, where we set the RTC clock as the
+ * parent. Since the EXT and PCLK are much faster than the RTC clock,
+ * the watchdog would kick after a maximum time of 5s, and we might
+ * want a slower kicking time.
+ */
+ ret = ingenic_tcu_register_clock(tcu, TCU_CLK_WDT, TCU_PARENT_RTC,
+ &ingenic_tcu_watchdog_clk_info,
+ tcu->clocks);
+ if (ret) {
+ pr_crit("cannot register watchdog clock\n");
+ goto err_unregister_timer_clocks;
+ }
+
+ if (tcu->soc_info->has_ost) {
+ ret = ingenic_tcu_register_clock(tcu, TCU_CLK_OST,
+ TCU_PARENT_EXT,
+ &ingenic_tcu_ost_clk_info,
+ tcu->clocks);
+ if (ret) {
+ pr_crit("cannot register ost clock\n");
+ goto err_unregister_watchdog_clock;
+ }
+ }
+
+ ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, tcu->clocks);
+ if (ret) {
+ pr_crit("cannot add OF clock provider\n");
+ goto err_unregister_ost_clock;
+ }
+
+ ingenic_tcu = tcu;
+
+ return 0;
+
+err_unregister_ost_clock:
+ if (tcu->soc_info->has_ost)
+ clk_hw_unregister(tcu->clocks->hws[i + 1]);
+err_unregister_watchdog_clock:
+ clk_hw_unregister(tcu->clocks->hws[i]);
+err_unregister_timer_clocks:
+ for (i = 0; i < tcu->clocks->num; i++)
+ if (tcu->clocks->hws[i])
+ clk_hw_unregister(tcu->clocks->hws[i]);
+ kfree(tcu->clocks);
+err_clk_disable:
+ if (tcu->soc_info->has_tcu_clk)
+ clk_disable_unprepare(tcu->clk);
+err_put_clk:
+ if (tcu->soc_info->has_tcu_clk)
+ clk_put(tcu->clk);
+err_free_tcu:
+ kfree(tcu);
+ return ret;
+}
+
+static int __maybe_unused tcu_pm_suspend(void)
+{
+ struct ingenic_tcu *tcu = ingenic_tcu;
+
+ if (tcu->clk)
+ clk_disable(tcu->clk);
+
+ return 0;
+}
+
+static void __maybe_unused tcu_pm_resume(void)
+{
+ struct ingenic_tcu *tcu = ingenic_tcu;
+
+ if (tcu->clk)
+ clk_enable(tcu->clk);
+}
+
+static struct syscore_ops __maybe_unused tcu_pm_ops = {
+ .suspend = tcu_pm_suspend,
+ .resume = tcu_pm_resume,
+};
+
+static void __init ingenic_tcu_init(struct device_node *np)
+{
+ int ret = ingenic_tcu_probe(np);
+
+ if (ret)
+ pr_crit("Failed to initialize TCU clocks: %d\n", ret);
+
+ if (IS_ENABLED(CONFIG_PM_SLEEP))
+ register_syscore_ops(&tcu_pm_ops);
+}
+
+CLK_OF_DECLARE(jz4740_cgu, "ingenic,jz4740-tcu", ingenic_tcu_init);
+CLK_OF_DECLARE(jz4725b_cgu, "ingenic,jz4725b-tcu", ingenic_tcu_init);
+CLK_OF_DECLARE(jz4770_cgu, "ingenic,jz4770-tcu", ingenic_tcu_init);
--
2.21.0.593.g511ec345e18

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