diff options
Diffstat (limited to 'drivers/timer/mchp-pit64b-timer.c')
-rw-r--r-- | drivers/timer/mchp-pit64b-timer.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/timer/mchp-pit64b-timer.c b/drivers/timer/mchp-pit64b-timer.c new file mode 100644 index 0000000000..ead8c9b84a --- /dev/null +++ b/drivers/timer/mchp-pit64b-timer.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * 64-bit Periodic Interval Timer driver + * + * Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries + * + * Author: Claudiu Beznea <claudiu.beznea@microchip.com> + */ + +#include <common.h> +#include <clk.h> +#include <dm.h> +#include <timer.h> +#include <asm/io.h> + +#define MCHP_PIT64B_CR 0x00 /* Control Register */ +#define MCHP_PIT64B_CR_START BIT(0) +#define MCHP_PIT64B_CR_SWRST BIT(8) +#define MCHP_PIT64B_MR 0x04 /* Mode Register */ +#define MCHP_PIT64B_MR_CONT BIT(0) +#define MCHP_PIT64B_LSB_PR 0x08 /* LSB Period Register */ +#define MCHP_PIT64B_MSB_PR 0x0C /* MSB Period Register */ +#define MCHP_PIT64B_TLSBR 0x20 /* Timer LSB Register */ +#define MCHP_PIT64B_TMSBR 0x24 /* Timer MSB Register */ + +struct mchp_pit64b_priv { + void __iomem *base; +}; + +static int mchp_pit64b_get_count(struct udevice *dev, u64 *count) +{ + struct mchp_pit64b_priv *priv = dev_get_priv(dev); + + u32 lsb = readl(priv->base + MCHP_PIT64B_TLSBR); + u32 msb = readl(priv->base + MCHP_PIT64B_TMSBR); + + *count = ((u64)msb << 32) | lsb; + + return 0; +} + +static int mchp_pit64b_probe(struct udevice *dev) +{ + struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); + struct mchp_pit64b_priv *priv = dev_get_priv(dev); + struct clk clk; + ulong rate; + int ret; + + priv->base = dev_read_addr_ptr(dev); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + ret = clk_get_by_index(dev, 0, &clk); + if (ret) + return ret; + + ret = clk_enable(&clk); + if (ret) + return ret; + + rate = clk_get_rate(&clk); + if (!rate) { + clk_disable(&clk); + return -ENOTSUPP; + } + + /* Reset the timer in case it was used by previous bootloaders. */ + writel(MCHP_PIT64B_CR_SWRST, priv->base + MCHP_PIT64B_CR); + + /* + * Use highest prescaller (for a peripheral clock running at 200MHz + * this will lead to the timer running at 12.5MHz) and continuous mode. + */ + writel((15 << 8) | MCHP_PIT64B_MR_CONT, priv->base + MCHP_PIT64B_MR); + uc_priv->clock_rate = rate / 16; + + /* + * Simulate free running counter by setting max values to period + * registers. + */ + writel(~0UL, priv->base + MCHP_PIT64B_MSB_PR); + writel(~0UL, priv->base + MCHP_PIT64B_LSB_PR); + + /* Start the timer. */ + writel(MCHP_PIT64B_CR_START, priv->base + MCHP_PIT64B_CR); + + return 0; +} + +static const struct timer_ops mchp_pit64b_ops = { + .get_count = mchp_pit64b_get_count, +}; + +static const struct udevice_id mchp_pit64b_ids[] = { + { .compatible = "microchip,sam9x60-pit64b", }, + { .compatible = "microchip,sama7g5-pit64b", }, + { } +}; + +U_BOOT_DRIVER(mchp_pit64b) = { + .name = "mchp-pit64b", + .id = UCLASS_TIMER, + .of_match = mchp_pit64b_ids, + .priv_auto_alloc_size = sizeof(struct mchp_pit64b_priv), + .probe = mchp_pit64b_probe, + .ops = &mchp_pit64b_ops, + .flags = DM_FLAG_PRE_RELOC, +}; |