1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
4 * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
15 /* Timer control1 register */
16 #define CR1_CEN BIT(0)
17 #define CR1_ARPE BIT(7)
19 /* Event Generation Register register */
22 /* Auto reload register for free running config */
23 #define GPT_FREE_RUNNING 0xFFFFFFFF
25 struct stm32_timer_regs {
49 struct stm32_timer_priv {
50 struct stm32_timer_regs *base;
53 static int stm32_timer_get_count(struct udevice *dev, u64 *count)
55 struct stm32_timer_priv *priv = dev_get_priv(dev);
56 struct stm32_timer_regs *regs = priv->base;
58 *count = readl(®s->cnt);
63 static int stm32_timer_probe(struct udevice *dev)
65 struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
66 struct stm32_timer_priv *priv = dev_get_priv(dev);
67 struct stm32_timer_regs *regs;
73 addr = dev_read_addr(dev);
74 if (addr == FDT_ADDR_T_NONE)
77 priv->base = (struct stm32_timer_regs *)addr;
79 ret = clk_get_by_index(dev, 0, &clk);
83 ret = clk_enable(&clk);
85 dev_err(dev, "failed to enable clock\n");
92 clrbits_le32(®s->cr1, CR1_CEN);
95 rate = clk_get_rate(&clk);
97 /* we set timer prescaler to obtain a 1MHz timer counter frequency */
98 psc = (rate / CONFIG_SYS_HZ_CLOCK) - 1;
99 writel(psc, ®s->psc);
101 /* Set timer frequency to 1MHz */
102 uc_priv->clock_rate = CONFIG_SYS_HZ_CLOCK;
104 /* Configure timer for auto-reload */
105 setbits_le32(®s->cr1, CR1_ARPE);
107 /* load value for auto reload */
108 writel(GPT_FREE_RUNNING, ®s->arr);
111 setbits_le32(®s->cr1, CR1_CEN);
113 /* Update generation */
114 setbits_le32(®s->egr, EGR_UG);
119 static const struct timer_ops stm32_timer_ops = {
120 .get_count = stm32_timer_get_count,
123 static const struct udevice_id stm32_timer_ids[] = {
124 { .compatible = "st,stm32-timer" },
128 U_BOOT_DRIVER(stm32_timer) = {
129 .name = "stm32_timer",
131 .of_match = stm32_timer_ids,
132 .priv_auto_alloc_size = sizeof(struct stm32_timer_priv),
133 .probe = stm32_timer_probe,
134 .ops = &stm32_timer_ops,