[PATCH v3 4/4] clk: bcm: Add BCM63268 timer clock and reset driver

Álvaro Fernández Rojas
2023-03-21T20:10:50Z

Add driver for BCM63268 timer clock and reset controller.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
---
v3: add missing <linux/io.h> include to fix build warning
v2: add changes suggested by Stephen Boyd

drivers/clk/bcm/Kconfig | 9 ++
drivers/clk/bcm/Makefile | 1 +
drivers/clk/bcm/clk-bcm63268-timer.c | 232 +++++++++++++++++++++++++++
3 files changed, 242 insertions(+)
create mode 100644 drivers/clk/bcm/clk-bcm63268-timer.c

diff --git a/drivers/clk/bcm/Kconfig b/drivers/clk/bcm/Kconfig
index 77266afb1c79..a972d763eb77 100644
--- a/drivers/clk/bcm/Kconfig
+++ b/drivers/clk/bcm/Kconfig
@@ -37,6 +37,15 @@ config CLK_BCM_63XX_GATE
Enable common clock framework support for Broadcom BCM63xx DSL SoCs
based on the MIPS architecture

+config CLK_BCM63268_TIMER
+ bool "Broadcom BCM63268 timer clock and reset support"
+ depends on BMIPS_GENERIC || COMPILE_TEST
+ default BMIPS_GENERIC
+ select RESET_CONTROLLER
+ help
+ Enable timer clock and reset support for Broadcom BCM63268 DSL SoCs
+ based on the MIPS architecture.
+
config CLK_BCM_KONA
bool "Broadcom Kona CCU clock support"
depends on ARCH_BCM_MOBILE || COMPILE_TEST
diff --git a/drivers/clk/bcm/Makefile b/drivers/clk/bcm/Makefile
index edb66b44cb27..d0b6f4b1fb08 100644
--- a/drivers/clk/bcm/Makefile
+++ b/drivers/clk/bcm/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_CLK_BCM_63XX) += clk-bcm63xx.o
obj-$(CONFIG_CLK_BCM_63XX_GATE) += clk-bcm63xx-gate.o
+obj-$(CONFIG_CLK_BCM63268_TIMER) += clk-bcm63268-timer.o
obj-$(CONFIG_CLK_BCM_KONA) += clk-kona.o
obj-$(CONFIG_CLK_BCM_KONA) += clk-kona-setup.o
obj-$(CONFIG_CLK_BCM_KONA) += clk-bcm281xx.o
diff --git a/drivers/clk/bcm/clk-bcm63268-timer.c b/drivers/clk/bcm/clk-bcm63268-timer.c
new file mode 100644
index 000000000000..6a1fdd193cb5
--- /dev/null
+++ b/drivers/clk/bcm/clk-bcm63268-timer.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * BCM63268 Timer Clock and Reset Controller Driver
+ *
+ * Copyright (C) 2023 Álvaro Fernández Rojas <noltari@gmail.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+
+#include <dt-bindings/clock/bcm63268-clock.h>
+
+#define BCM63268_TIMER_RESET_SLEEP_MIN_US 10000
+#define BCM63268_TIMER_RESET_SLEEP_MAX_US 20000
+
+struct bcm63268_tclkrst_hw {
+ void __iomem *regs;
+ spinlock_t lock;
+
+ struct reset_controller_dev rcdev;
+ struct clk_hw_onecell_data data;
+};
+
+struct bcm63268_tclk_table_entry {
+ const char * const name;
+ u8 bit;
+};
+
+static const struct bcm63268_tclk_table_entry bcm63268_timer_clocks[] = {
+ {
+ .name = "ephy1",
+ .bit = BCM63268_TCLK_EPHY1,
+ }, {
+ .name = "ephy2",
+ .bit = BCM63268_TCLK_EPHY2,
+ }, {
+ .name = "ephy3",
+ .bit = BCM63268_TCLK_EPHY3,
+ }, {
+ .name = "gphy1",
+ .bit = BCM63268_TCLK_GPHY1,
+ }, {
+ .name = "dsl",
+ .bit = BCM63268_TCLK_DSL,
+ }, {
+ .name = "wakeon_ephy",
+ .bit = BCM63268_TCLK_WAKEON_EPHY,
+ }, {
+ .name = "wakeon_dsl",
+ .bit = BCM63268_TCLK_WAKEON_DSL,
+ }, {
+ .name = "fap1_pll",
+ .bit = BCM63268_TCLK_FAP1,
+ }, {
+ .name = "fap2_pll",
+ .bit = BCM63268_TCLK_FAP2,
+ }, {
+ .name = "uto_50",
+ .bit = BCM63268_TCLK_UTO_50,
+ }, {
+ .name = "uto_extin",
+ .bit = BCM63268_TCLK_UTO_EXTIN,
+ }, {
+ .name = "usb_ref",
+ .bit = BCM63268_TCLK_USB_REF,
+ }, {
+ /* sentinel */
+ }
+};
+
+static inline struct bcm63268_tclkrst_hw *
+to_bcm63268_timer_reset(struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct bcm63268_tclkrst_hw, rcdev);
+}
+
+static int bcm63268_timer_reset_update(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ struct bcm63268_tclkrst_hw *reset = to_bcm63268_timer_reset(rcdev);
+ unsigned long flags;
+ uint32_t val;
+
+ spin_lock_irqsave(&reset->lock, flags);
+ val = __raw_readl(reset->regs);
+ if (assert)
+ val &= ~BIT(id);
+ else
+ val |= BIT(id);
+ __raw_writel(val, reset->regs);
+ spin_unlock_irqrestore(&reset->lock, flags);
+
+ return 0;
+}
+
+static int bcm63268_timer_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return bcm63268_timer_reset_update(rcdev, id, true);
+}
+
+static int bcm63268_timer_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return bcm63268_timer_reset_update(rcdev, id, false);
+}
+
+static int bcm63268_timer_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ bcm63268_timer_reset_update(rcdev, id, true);
+ usleep_range(BCM63268_TIMER_RESET_SLEEP_MIN_US,
+ BCM63268_TIMER_RESET_SLEEP_MAX_US);
+
+ bcm63268_timer_reset_update(rcdev, id, false);
+ /*
+ * Ensure component is taken out reset state by sleeping also after
+ * deasserting the reset. Otherwise, the component may not be ready
+ * for operation.
+ */
+ usleep_range(BCM63268_TIMER_RESET_SLEEP_MIN_US,
+ BCM63268_TIMER_RESET_SLEEP_MAX_US);
+
+ return 0;
+}
+
+static int bcm63268_timer_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct bcm63268_tclkrst_hw *reset = to_bcm63268_timer_reset(rcdev);
+
+ return !(__raw_readl(reset->regs) & BIT(id));
+}
+
+static struct reset_control_ops bcm63268_timer_reset_ops = {
+ .assert = bcm63268_timer_reset_assert,
+ .deassert = bcm63268_timer_reset_deassert,
+ .reset = bcm63268_timer_reset_reset,
+ .status = bcm63268_timer_reset_status,
+};
+
+static int bcm63268_tclk_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct bcm63268_tclk_table_entry *entry, *table;
+ struct bcm63268_tclkrst_hw *hw;
+ struct clk_hw *clk;
+ u8 maxbit = 0;
+ int i, ret;
+
+ table = of_device_get_match_data(dev);
+ if (!table)
+ return -EINVAL;
+
+ for (entry = table; entry->name; entry++)
+ maxbit = max(maxbit, entry->bit);
+ maxbit++;
+
+ hw = devm_kzalloc(&pdev->dev, struct_size(hw, data.hws, maxbit),
+ GFP_KERNEL);
+ if (!hw)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, hw);
+
+ spin_lock_init(&hw->lock);
+
+ hw->data.num = maxbit;
+ for (i = 0; i < maxbit; i++)
+ hw->data.hws[i] = ERR_PTR(-ENODEV);
+
+ hw->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(hw->regs))
+ return PTR_ERR(hw->regs);
+
+ for (entry = table; entry->name; entry++) {
+ clk = clk_hw_register_gate(dev, entry->name, NULL, 0,
+ hw->regs, entry->bit,
+ CLK_GATE_BIG_ENDIAN, &hw->lock);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ goto out_err;
+ }
+
+ hw->data.hws[entry->bit] = clk;
+ }
+
+ ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+ &hw->data);
+ if (ret)
+ return ret;
+
+ hw->rcdev.of_node = dev->of_node;
+ hw->rcdev.ops = &bcm63268_timer_reset_ops;
+
+ ret = devm_reset_controller_register(dev, &hw->rcdev);
+ if (ret)
+ dev_err(dev, "Failed to register reset controller\n");
+
+ return 0;
+
+out_err:
+ for (i = 0; i < hw->data.num; i++) {
+ if (!IS_ERR(hw->data.hws[i]))
+ clk_hw_unregister_gate(hw->data.hws[i]);
+ }
+
+ return ret;
+}
+
+static const struct of_device_id bcm63268_tclk_dt_ids[] = {
+ {
+ .compatible = "brcm,bcm63268-timer-clocks",
+ .data = &bcm63268_timer_clocks,
+ }, {
+ /* sentinel */
+ }
+};
+
+static struct platform_driver bcm63268_tclk = {
+ .probe = bcm63268_tclk_probe,
+ .driver = {
+ .name = "bcm63268-timer-clock",
+ .of_match_table = bcm63268_tclk_dt_ids,
+ },
+};
+builtin_platform_driver(bcm63268_tclk);
--
2.30.2