timer: mchp-pit64b: add support for pit64b
Add support for Microchip PIT64B timer. The timer is 64 bit length and
is used as a free running counter (in continuous mode with highest values
for period registers). The clock feeding the timer would be no more
than 12.5MHz.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
index 6370244..12020e4 100644
--- a/drivers/timer/Kconfig
+++ b/drivers/timer/Kconfig
@@ -213,4 +213,11 @@
Select this to enable support for the timer found on
MediaTek devices.
+config MCHP_PIT64B_TIMER
+ bool "Microchip 64-bit periodic interval timer support"
+ depends on TIMER
+ help
+ Select this to enable support for Microchip 64-bit periodic
+ interval timer.
+
endmenu
diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
index c22ffeb..3a4d74b 100644
--- a/drivers/timer/Makefile
+++ b/drivers/timer/Makefile
@@ -22,3 +22,4 @@
obj-$(CONFIG_STM32_TIMER) += stm32_timer.o
obj-$(CONFIG_X86_TSC_TIMER) += tsc_timer.o
obj-$(CONFIG_MTK_TIMER) += mtk_timer.o
+obj-$(CONFIG_MCHP_PIT64B_TIMER) += mchp-pit64b-timer.o
diff --git a/drivers/timer/mchp-pit64b-timer.c b/drivers/timer/mchp-pit64b-timer.c
new file mode 100644
index 0000000..ead8c9b
--- /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,
+};