[PATCH v2 08/10] reset: Add Actions Semi S900 SoC Reset Management Unit support

From: Manivannan Sadhasivam
Date: Tue Jul 31 2018 - 23:41:19 EST

Add Reset Management Unit (RMU) support for Actions Semi S900 SoC
of the Owl family series. RMU belongs to the Owl SoCs system-controller
which also includes CMU (Clock Management Unit).

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
drivers/reset/Kconfig | 6 ++
drivers/reset/Makefile | 1 +
drivers/reset/reset-owl.c | 192 ++++++++++++++++++++++++++++++++++++++
3 files changed, 199 insertions(+)
create mode 100644 drivers/reset/reset-owl.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index c0b292be1b72..90627430569b 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -73,6 +73,12 @@ config RESET_MESON
help
This enables the reset driver for Amlogic Meson SoCs.

+config RESET_OWL
+ bool "Actions Semi Owl SoCs Reset Driver" if COMPILE_TEST
+ default ARCH_ACTIONS
+ help
+ This enables the reset controller driver for Actions Semi Owl SoCs.
+
config RESET_OXNAS
bool

diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index c1261dcfe9ad..fa655319cf17 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
obj-$(CONFIG_RESET_MESON) += reset-meson.o
+obj-$(CONFIG_RESET_OWL) += reset-owl.o
obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
diff --git a/drivers/reset/reset-owl.c b/drivers/reset/reset-owl.c
new file mode 100644
index 000000000000..c4f07691fb36
--- /dev/null
+++ b/drivers/reset/reset-owl.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Actions Semi Owl SoCs Reset Management Unit driver
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
+
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+#include <dt-bindings/reset/actions,s900-rmu.h>
+
+#define CMU_DEVRST0 0x00a8
+#define CMU_DEVRST1 0x00ac
+
+struct owl_reset_map {
+ u32 reg;
+ u32 bit;
+};
+
+struct owl_reset_hw {
+ const struct owl_reset_map *resets;
+ u32 num_resets;
+};
+
+struct owl_reset {
+ struct reset_controller_dev rcdev;
+ const struct owl_reset_hw *hw;
+ struct regmap *regmap;
+};
+
+static const struct owl_reset_map s900_resets[] = {
+ [S900_RESET_DMAC] = { CMU_DEVRST0, BIT(0) },
+ [S900_RESET_SRAMI] = { CMU_DEVRST0, BIT(1) },
+ [S900_RESET_DDR_CTL_PHY] = { CMU_DEVRST0, BIT(2) },
+ [S900_RESET_NANDC0] = { CMU_DEVRST0, BIT(3) },
+ [S900_RESET_SD0] = { CMU_DEVRST0, BIT(4) },
+ [S900_RESET_SD1] = { CMU_DEVRST0, BIT(5) },
+ [S900_RESET_PCM1] = { CMU_DEVRST0, BIT(6) },
+ [S900_RESET_DE] = { CMU_DEVRST0, BIT(7) },
+ [S900_RESET_LVDS] = { CMU_DEVRST0, BIT(8) },
+ [S900_RESET_SD2] = { CMU_DEVRST0, BIT(9) },
+ [S900_RESET_DSI] = { CMU_DEVRST0, BIT(10) },
+ [S900_RESET_CSI0] = { CMU_DEVRST0, BIT(11) },
+ [S900_RESET_BISP_AXI] = { CMU_DEVRST0, BIT(12) },
+ [S900_RESET_CSI1] = { CMU_DEVRST0, BIT(13) },
+ [S900_RESET_GPIO] = { CMU_DEVRST0, BIT(15) },
+ [S900_RESET_EDP] = { CMU_DEVRST0, BIT(16) },
+ [S900_RESET_AUDIO] = { CMU_DEVRST0, BIT(17) },
+ [S900_RESET_PCM0] = { CMU_DEVRST0, BIT(18) },
+ [S900_RESET_HDE] = { CMU_DEVRST0, BIT(21) },
+ [S900_RESET_GPU3D_PA] = { CMU_DEVRST0, BIT(22) },
+ [S900_RESET_IMX] = { CMU_DEVRST0, BIT(23) },
+ [S900_RESET_SE] = { CMU_DEVRST0, BIT(24) },
+ [S900_RESET_NANDC1] = { CMU_DEVRST0, BIT(25) },
+ [S900_RESET_SD3] = { CMU_DEVRST0, BIT(26) },
+ [S900_RESET_GIC] = { CMU_DEVRST0, BIT(27) },
+ [S900_RESET_GPU3D_PB] = { CMU_DEVRST0, BIT(28) },
+ [S900_RESET_DDR_CTL_PHY_AXI] = { CMU_DEVRST0, BIT(29) },
+ [S900_RESET_CMU_DDR] = { CMU_DEVRST0, BIT(30) },
+ [S900_RESET_DMM] = { CMU_DEVRST0, BIT(31) },
+ [S900_RESET_USB2HUB] = { CMU_DEVRST1, BIT(0) },
+ [S900_RESET_USB2HSIC] = { CMU_DEVRST1, BIT(1) },
+ [S900_RESET_HDMI] = { CMU_DEVRST1, BIT(2) },
+ [S900_RESET_HDCP2TX] = { CMU_DEVRST1, BIT(3) },
+ [S900_RESET_UART6] = { CMU_DEVRST1, BIT(4) },
+ [S900_RESET_UART0] = { CMU_DEVRST1, BIT(5) },
+ [S900_RESET_UART1] = { CMU_DEVRST1, BIT(6) },
+ [S900_RESET_UART2] = { CMU_DEVRST1, BIT(7) },
+ [S900_RESET_SPI0] = { CMU_DEVRST1, BIT(8) },
+ [S900_RESET_SPI1] = { CMU_DEVRST1, BIT(9) },
+ [S900_RESET_SPI2] = { CMU_DEVRST1, BIT(10) },
+ [S900_RESET_SPI3] = { CMU_DEVRST1, BIT(11) },
+ [S900_RESET_I2C0] = { CMU_DEVRST1, BIT(12) },
+ [S900_RESET_I2C1] = { CMU_DEVRST1, BIT(13) },
+ [S900_RESET_USB3] = { CMU_DEVRST1, BIT(14) },
+ [S900_RESET_UART3] = { CMU_DEVRST1, BIT(15) },
+ [S900_RESET_UART4] = { CMU_DEVRST1, BIT(16) },
+ [S900_RESET_UART5] = { CMU_DEVRST1, BIT(17) },
+ [S900_RESET_I2C2] = { CMU_DEVRST1, BIT(18) },
+ [S900_RESET_I2C3] = { CMU_DEVRST1, BIT(19) },
+};
+
+static const struct owl_reset_hw s900_reset_hw = {
+ .resets = s900_resets,
+ .num_resets = ARRAY_SIZE(s900_resets),
+};
+
+static inline struct owl_reset *to_owl_reset(struct reset_controller_dev *rcdev)
+{
+ return container_of(rcdev, struct owl_reset, rcdev);
+}
+
+static int owl_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct owl_reset *reset = to_owl_reset(rcdev);
+ const struct owl_reset_map *map = &reset->hw->resets[id];
+
+ return regmap_update_bits(reset->regmap, map->reg, map->bit, 0);
+}
+
+static int owl_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct owl_reset *reset = to_owl_reset(rcdev);
+ const struct owl_reset_map *map = &reset->hw->resets[id];
+
+ return regmap_update_bits(reset->regmap, map->reg, map->bit, map->bit);
+}
+
+static int owl_reset_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ owl_reset_assert(rcdev, id);
+ udelay(1);
+ owl_reset_deassert(rcdev, id);
+
+ return 0;
+}
+
+static int owl_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct owl_reset *reset = to_owl_reset(rcdev);
+ const struct owl_reset_map *map = &reset->hw->resets[id];
+ u32 reg;
+ int ret;
+
+ ret = regmap_read(reset->regmap, map->reg, &reg);
+ if (ret)
+ return ret;
+
+ /*
+ * The reset control API expects 0 if reset is not asserted,
+ * which is the opposite of what our hardware uses.
+ */
+ return !(map->bit & reg);
+}
+
+static const struct reset_control_ops owl_reset_ops = {
+ .assert = owl_reset_assert,
+ .deassert = owl_reset_deassert,
+ .reset = owl_reset_reset,
+ .status = owl_reset_status,
+};
+
+static int owl_reset_probe(struct platform_device *pdev)
+{
+ struct owl_reset *reset;
+ struct regmap *regmap;
+ const struct owl_reset_hw *hw;
+
+ hw = of_device_get_match_data(&pdev->dev);
+ if (!hw)
+ return -EINVAL;
+
+ reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL);
+ if (!reset)
+ return -ENOMEM;
+
+ regmap = syscon_node_to_regmap(of_get_parent(pdev->dev.of_node));
+ if (IS_ERR(regmap)) {
+ dev_err(&pdev->dev, "failed to get regmap\n");
+ return PTR_ERR(regmap);
+ }
+
+ reset->rcdev.of_node = pdev->dev.of_node;
+ reset->rcdev.ops = &owl_reset_ops;
+ reset->rcdev.nr_resets = hw->num_resets;
+ reset->hw = hw;
+ reset->regmap = regmap;
+
+ return devm_reset_controller_register(&pdev->dev, &reset->rcdev);
+}
+
+static const struct of_device_id owl_reset_of_match[] = {
+ { .compatible = "actions,s900-rmu", .data = &s900_reset_hw },
+ { /* sentinel */ }
+};
+
+static struct platform_driver owl_reset_driver = {
+ .probe = owl_reset_probe,
+ .driver = {
+ .name = "owl-reset",
+ .of_match_table = owl_reset_of_match,
+ },
+};
+builtin_platform_driver(owl_reset_driver);
--
2.17.1