diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/clocksource/timer-mediatek.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-mediatek.c b/drivers/clocksource/timer-mediatek.c new file mode 100644 index 000000000..d5b29fd03 --- /dev/null +++ b/drivers/clocksource/timer-mediatek.c @@ -0,0 +1,455 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Mediatek SoCs General-Purpose Timer handling. + * + * Copyright (C) 2014 Matthias Brugger + * + * Matthias Brugger <matthias.bgg@gmail.com> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/clockchips.h> +#include <linux/clocksource.h> +#include <linux/interrupt.h> +#include <linux/irqreturn.h> +#include <linux/sched_clock.h> +#include <linux/slab.h> +#include "timer-of.h" + +#define TIMER_CLK_EVT (1) +#define TIMER_CLK_SRC (2) + +#define TIMER_SYNC_TICKS (3) + +/* cpux mcusys wrapper */ +#define CPUX_CON_REG 0x0 +#define CPUX_IDX_REG 0x4 + +/* cpux */ +#define CPUX_IDX_GLOBAL_CTRL 0x0 + #define CPUX_ENABLE BIT(0) + #define CPUX_CLK_DIV_MASK GENMASK(10, 8) + #define CPUX_CLK_DIV1 BIT(8) + #define CPUX_CLK_DIV2 BIT(9) + #define CPUX_CLK_DIV4 BIT(10) +#define CPUX_IDX_GLOBAL_IRQ 0x30 + +/* gpt */ +#define GPT_IRQ_EN_REG 0x00 +#define GPT_IRQ_ENABLE(val) BIT((val) - 1) +#define GPT_IRQ_ACK_REG 0x08 +#define GPT_IRQ_ACK(val) BIT((val) - 1) + +#define GPT_CTRL_REG(val) (0x10 * (val)) +#define GPT_CTRL_OP(val) (((val) & 0x3) << 4) +#define GPT_CTRL_OP_ONESHOT (0) +#define GPT_CTRL_OP_REPEAT (1) +#define GPT_CTRL_OP_FREERUN (3) +#define GPT_CTRL_CLEAR (2) +#define GPT_CTRL_ENABLE (1) +#define GPT_CTRL_DISABLE (0) + +#define GPT_CLK_REG(val) (0x04 + (0x10 * (val))) +#define GPT_CLK_SRC(val) (((val) & 0x1) << 4) +#define GPT_CLK_SRC_SYS13M (0) +#define GPT_CLK_SRC_RTC32K (1) +#define GPT_CLK_DIV1 (0x0) +#define GPT_CLK_DIV2 (0x1) + +#define GPT_CNT_REG(val) (0x08 + (0x10 * (val))) +#define GPT_CMP_REG(val) (0x0C + (0x10 * (val))) + +/* system timer */ +#define SYST_BASE (0x40) + +#define SYST_CON (SYST_BASE + 0x0) +#define SYST_VAL (SYST_BASE + 0x4) + +#define SYST_CON_REG(to) (timer_of_base(to) + SYST_CON) +#define SYST_VAL_REG(to) (timer_of_base(to) + SYST_VAL) + +/* + * SYST_CON_EN: Clock enable. Shall be set to + * - Start timer countdown. + * - Allow timeout ticks being updated. + * - Allow changing interrupt status,like clear irq pending. + * + * SYST_CON_IRQ_EN: Set to enable interrupt. + * + * SYST_CON_IRQ_CLR: Set to clear interrupt. + */ +#define SYST_CON_EN BIT(0) +#define SYST_CON_IRQ_EN BIT(1) +#define SYST_CON_IRQ_CLR BIT(4) + +static void __iomem *gpt_sched_reg __read_mostly; + +static u32 mtk_cpux_readl(u32 reg_idx, struct timer_of *to) +{ + writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG); + return readl(timer_of_base(to) + CPUX_CON_REG); +} + +static void mtk_cpux_writel(u32 val, u32 reg_idx, struct timer_of *to) +{ + writel(reg_idx, timer_of_base(to) + CPUX_IDX_REG); + writel(val, timer_of_base(to) + CPUX_CON_REG); +} + +static void mtk_cpux_set_irq(struct timer_of *to, bool enable) +{ + const unsigned long *irq_mask = cpumask_bits(cpu_possible_mask); + u32 val; + + val = mtk_cpux_readl(CPUX_IDX_GLOBAL_IRQ, to); + + if (enable) + val |= *irq_mask; + else + val &= ~(*irq_mask); + + mtk_cpux_writel(val, CPUX_IDX_GLOBAL_IRQ, to); +} + +static int mtk_cpux_clkevt_shutdown(struct clock_event_device *clkevt) +{ + /* Clear any irq */ + mtk_cpux_set_irq(to_timer_of(clkevt), false); + + /* + * Disabling CPUXGPT timer will crash the platform, especially + * if Trusted Firmware is using it (usually, for sleep states), + * so we only mask the IRQ and call it a day. + */ + return 0; +} + +static int mtk_cpux_clkevt_resume(struct clock_event_device *clkevt) +{ + mtk_cpux_set_irq(to_timer_of(clkevt), true); + return 0; +} + +static void mtk_syst_ack_irq(struct timer_of *to) +{ + /* Clear and disable interrupt */ + writel(SYST_CON_EN, SYST_CON_REG(to)); + writel(SYST_CON_IRQ_CLR | SYST_CON_EN, SYST_CON_REG(to)); +} + +static irqreturn_t mtk_syst_handler(int irq, void *dev_id) +{ + struct clock_event_device *clkevt = dev_id; + struct timer_of *to = to_timer_of(clkevt); + + mtk_syst_ack_irq(to); + clkevt->event_handler(clkevt); + + return IRQ_HANDLED; +} + +static int mtk_syst_clkevt_next_event(unsigned long ticks, + struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + /* Enable clock to allow timeout tick update later */ + writel(SYST_CON_EN, SYST_CON_REG(to)); + + /* + * Write new timeout ticks. Timer shall start countdown + * after timeout ticks are updated. + */ + writel(ticks, SYST_VAL_REG(to)); + + /* Enable interrupt */ + writel(SYST_CON_EN | SYST_CON_IRQ_EN, SYST_CON_REG(to)); + + return 0; +} + +static int mtk_syst_clkevt_shutdown(struct clock_event_device *clkevt) +{ + /* Clear any irq */ + mtk_syst_ack_irq(to_timer_of(clkevt)); + + /* Disable timer */ + writel(0, SYST_CON_REG(to_timer_of(clkevt))); + + return 0; +} + +static int mtk_syst_clkevt_resume(struct clock_event_device *clkevt) +{ + return mtk_syst_clkevt_shutdown(clkevt); +} + +static int mtk_syst_clkevt_oneshot(struct clock_event_device *clkevt) +{ + return 0; +} + +static u64 notrace mtk_gpt_read_sched_clock(void) +{ + return readl_relaxed(gpt_sched_reg); +} + +static void mtk_gpt_clkevt_time_stop(struct timer_of *to, u8 timer) +{ + u32 val; + + val = readl(timer_of_base(to) + GPT_CTRL_REG(timer)); + writel(val & ~GPT_CTRL_ENABLE, timer_of_base(to) + + GPT_CTRL_REG(timer)); +} + +static void mtk_gpt_clkevt_time_setup(struct timer_of *to, + unsigned long delay, u8 timer) +{ + writel(delay, timer_of_base(to) + GPT_CMP_REG(timer)); +} + +static void mtk_gpt_clkevt_time_start(struct timer_of *to, + bool periodic, u8 timer) +{ + u32 val; + + /* Acknowledge interrupt */ + writel(GPT_IRQ_ACK(timer), timer_of_base(to) + GPT_IRQ_ACK_REG); + + val = readl(timer_of_base(to) + GPT_CTRL_REG(timer)); + + /* Clear 2 bit timer operation mode field */ + val &= ~GPT_CTRL_OP(0x3); + + if (periodic) + val |= GPT_CTRL_OP(GPT_CTRL_OP_REPEAT); + else + val |= GPT_CTRL_OP(GPT_CTRL_OP_ONESHOT); + + writel(val | GPT_CTRL_ENABLE | GPT_CTRL_CLEAR, + timer_of_base(to) + GPT_CTRL_REG(timer)); +} + +static int mtk_gpt_clkevt_shutdown(struct clock_event_device *clk) +{ + mtk_gpt_clkevt_time_stop(to_timer_of(clk), TIMER_CLK_EVT); + + return 0; +} + +static int mtk_gpt_clkevt_set_periodic(struct clock_event_device *clk) +{ + struct timer_of *to = to_timer_of(clk); + + mtk_gpt_clkevt_time_stop(to, TIMER_CLK_EVT); + mtk_gpt_clkevt_time_setup(to, to->of_clk.period, TIMER_CLK_EVT); + mtk_gpt_clkevt_time_start(to, true, TIMER_CLK_EVT); + + return 0; +} + +static int mtk_gpt_clkevt_next_event(unsigned long event, + struct clock_event_device *clk) +{ + struct timer_of *to = to_timer_of(clk); + + mtk_gpt_clkevt_time_stop(to, TIMER_CLK_EVT); + mtk_gpt_clkevt_time_setup(to, event, TIMER_CLK_EVT); + mtk_gpt_clkevt_time_start(to, false, TIMER_CLK_EVT); + + return 0; +} + +static irqreturn_t mtk_gpt_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *clkevt = (struct clock_event_device *)dev_id; + struct timer_of *to = to_timer_of(clkevt); + + /* Acknowledge timer0 irq */ + writel(GPT_IRQ_ACK(TIMER_CLK_EVT), timer_of_base(to) + GPT_IRQ_ACK_REG); + clkevt->event_handler(clkevt); + + return IRQ_HANDLED; +} + +static void +__init mtk_gpt_setup(struct timer_of *to, u8 timer, u8 option) +{ + writel(GPT_CTRL_CLEAR | GPT_CTRL_DISABLE, + timer_of_base(to) + GPT_CTRL_REG(timer)); + + writel(GPT_CLK_SRC(GPT_CLK_SRC_SYS13M) | GPT_CLK_DIV1, + timer_of_base(to) + GPT_CLK_REG(timer)); + + writel(0x0, timer_of_base(to) + GPT_CMP_REG(timer)); + + writel(GPT_CTRL_OP(option) | GPT_CTRL_ENABLE, + timer_of_base(to) + GPT_CTRL_REG(timer)); +} + +static void mtk_gpt_enable_irq(struct timer_of *to, u8 timer) +{ + u32 val; + + /* Disable all interrupts */ + writel(0x0, timer_of_base(to) + GPT_IRQ_EN_REG); + + /* Acknowledge all spurious pending interrupts */ + writel(0x3f, timer_of_base(to) + GPT_IRQ_ACK_REG); + + val = readl(timer_of_base(to) + GPT_IRQ_EN_REG); + writel(val | GPT_IRQ_ENABLE(timer), + timer_of_base(to) + GPT_IRQ_EN_REG); +} + +static void mtk_gpt_resume(struct clock_event_device *clk) +{ + struct timer_of *to = to_timer_of(clk); + + mtk_gpt_enable_irq(to, TIMER_CLK_EVT); +} + +static void mtk_gpt_suspend(struct clock_event_device *clk) +{ + struct timer_of *to = to_timer_of(clk); + + /* Disable all interrupts */ + writel(0x0, timer_of_base(to) + GPT_IRQ_EN_REG); + + /* + * This is called with interrupts disabled, + * so we need to ack any interrupt that is pending + * or for example ATF will prevent a suspend from completing. + */ + writel(0x3f, timer_of_base(to) + GPT_IRQ_ACK_REG); +} + +static struct timer_of to = { + .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK, + + .clkevt = { + .name = "mtk-clkevt", + .rating = 300, + .cpumask = cpu_possible_mask, + }, + + .of_irq = { + .flags = IRQF_TIMER | IRQF_IRQPOLL, + }, +}; + +static int __init mtk_cpux_init(struct device_node *node) +{ + static struct timer_of to_cpux; + u32 freq, val; + int ret; + + /* + * There are per-cpu interrupts for the CPUX General Purpose Timer + * but since this timer feeds the AArch64 System Timer we can rely + * on the CPU timer PPIs as well, so we don't declare TIMER_OF_IRQ. + */ + to_cpux.flags = TIMER_OF_BASE | TIMER_OF_CLOCK; + to_cpux.clkevt.name = "mtk-cpuxgpt"; + to_cpux.clkevt.rating = 10; + to_cpux.clkevt.cpumask = cpu_possible_mask; + to_cpux.clkevt.set_state_shutdown = mtk_cpux_clkevt_shutdown; + to_cpux.clkevt.tick_resume = mtk_cpux_clkevt_resume; + + /* If this fails, bad things are about to happen... */ + ret = timer_of_init(node, &to_cpux); + if (ret) { + WARN(1, "Cannot start CPUX timers.\n"); + return ret; + } + + /* + * Check if we're given a clock with the right frequency for this + * timer, otherwise warn but keep going with the setup anyway, as + * that makes it possible to still boot the kernel, even though + * it may not work correctly (random lockups, etc). + * The reason behind this is that having an early UART may not be + * possible for everyone and this gives a chance to retrieve kmsg + * for eventual debugging even on consumer devices. + */ + freq = timer_of_rate(&to_cpux); + if (freq > 13000000) + WARN(1, "Requested unsupported timer frequency %u\n", freq); + + /* Clock input is 26MHz, set DIV2 to achieve 13MHz clock */ + val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to_cpux); + val &= ~CPUX_CLK_DIV_MASK; + val |= CPUX_CLK_DIV2; + mtk_cpux_writel(val, CPUX_IDX_GLOBAL_CTRL, &to_cpux); + + /* Enable all CPUXGPT timers */ + val = mtk_cpux_readl(CPUX_IDX_GLOBAL_CTRL, &to_cpux); + mtk_cpux_writel(val | CPUX_ENABLE, CPUX_IDX_GLOBAL_CTRL, &to_cpux); + + clockevents_config_and_register(&to_cpux.clkevt, timer_of_rate(&to_cpux), + TIMER_SYNC_TICKS, 0xffffffff); + + return 0; +} + +static int __init mtk_syst_init(struct device_node *node) +{ + int ret; + + to.clkevt.features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_ONESHOT; + to.clkevt.set_state_shutdown = mtk_syst_clkevt_shutdown; + to.clkevt.set_state_oneshot = mtk_syst_clkevt_oneshot; + to.clkevt.tick_resume = mtk_syst_clkevt_resume; + to.clkevt.set_next_event = mtk_syst_clkevt_next_event; + to.of_irq.handler = mtk_syst_handler; + + ret = timer_of_init(node, &to); + if (ret) + return ret; + + clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), + TIMER_SYNC_TICKS, 0xffffffff); + + return 0; +} + +static int __init mtk_gpt_init(struct device_node *node) +{ + int ret; + + to.clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + to.clkevt.set_state_shutdown = mtk_gpt_clkevt_shutdown; + to.clkevt.set_state_periodic = mtk_gpt_clkevt_set_periodic; + to.clkevt.set_state_oneshot = mtk_gpt_clkevt_shutdown; + to.clkevt.tick_resume = mtk_gpt_clkevt_shutdown; + to.clkevt.set_next_event = mtk_gpt_clkevt_next_event; + to.clkevt.suspend = mtk_gpt_suspend; + to.clkevt.resume = mtk_gpt_resume; + to.of_irq.handler = mtk_gpt_interrupt; + + ret = timer_of_init(node, &to); + if (ret) + return ret; + + /* Configure clock source */ + mtk_gpt_setup(&to, TIMER_CLK_SRC, GPT_CTRL_OP_FREERUN); + clocksource_mmio_init(timer_of_base(&to) + GPT_CNT_REG(TIMER_CLK_SRC), + node->name, timer_of_rate(&to), 300, 32, + clocksource_mmio_readl_up); + gpt_sched_reg = timer_of_base(&to) + GPT_CNT_REG(TIMER_CLK_SRC); + sched_clock_register(mtk_gpt_read_sched_clock, 32, timer_of_rate(&to)); + + /* Configure clock event */ + mtk_gpt_setup(&to, TIMER_CLK_EVT, GPT_CTRL_OP_REPEAT); + clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), + TIMER_SYNC_TICKS, 0xffffffff); + + mtk_gpt_enable_irq(&to, TIMER_CLK_EVT); + + return 0; +} +TIMER_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer", mtk_gpt_init); +TIMER_OF_DECLARE(mtk_mt6765, "mediatek,mt6765-timer", mtk_syst_init); +TIMER_OF_DECLARE(mtk_mt6795, "mediatek,mt6795-systimer", mtk_cpux_init); |