diff options
Diffstat (limited to 'drivers/clk/ingenic/tcu.c')
| -rw-r--r-- | drivers/clk/ingenic/tcu.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/clk/ingenic/tcu.c b/drivers/clk/ingenic/tcu.c new file mode 100644 index 000000000000..a1a5f9cb439e --- /dev/null +++ b/drivers/clk/ingenic/tcu.c @@ -0,0 +1,474 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * JZ47xx SoCs TCU clocks driver + * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net> + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/clockchips.h> +#include <linux/mfd/ingenic-tcu.h> +#include <linux/mfd/syscon.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, }, + { /* sentinel */ } +}; + +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 = device_node_to_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_DRIVER(jz4740_cgu, "ingenic,jz4740-tcu", ingenic_tcu_init); +CLK_OF_DECLARE_DRIVER(jz4725b_cgu, "ingenic,jz4725b-tcu", ingenic_tcu_init); +CLK_OF_DECLARE_DRIVER(jz4770_cgu, "ingenic,jz4770-tcu", ingenic_tcu_init); |