linux-kernel - [PATCH v4 2/3] reset: add driver for imx8ulp SIM reset controller

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Message-Id: <20240915114311.75496-3-laurentiu.mihalcea@nxp.com>
Date: Sun, 15 Sep 2024 07:43:10 -0400
From: Laurentiu Mihalcea <laurentiumihalcea111@...il.com>
To: Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Shawn Guo <shawnguo@...nel.org>,
	Philipp Zabel <p.zabel@...gutronix.de>,
	Liu Ying <victor.liu@....com>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Conor Dooley <conor+dt@...nel.org>
Cc: devicetree@...r.kernel.org,
	imx@...ts.linux.dev,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v4 2/3] reset: add driver for imx8ulp SIM reset controller

Certain components can be reset via the SIM module.
Add reset controller driver for the SIM module to
allow drivers for said components to control the
reset signal(s).

Signed-off-by: Liu Ying <victor.liu@....com>
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@....com>
---
 drivers/reset/Kconfig             |   7 ++
 drivers/reset/Makefile            |   1 +
 drivers/reset/reset-imx8ulp-sim.c | 106 ++++++++++++++++++++++++++++++
 3 files changed, 114 insertions(+)
 create mode 100644 drivers/reset/reset-imx8ulp-sim.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 5484a65f66b9..492081354d03 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -113,6 +113,13 @@ config RESET_IMX8MP_AUDIOMIX
 	help
 	  This enables the reset controller driver for i.MX8MP AudioMix
 
+config RESET_IMX8ULP_SIM
+	tristate "i.MX8ULP SIM Reset Driver"
+	depends on ARCH_MXC
+	help
+	  This enables the SIM (System Integration Module) reset driver
+	  for i.MX8ULP SoC.
+
 config RESET_INTEL_GW
 	bool "Intel Reset Controller Driver"
 	depends on X86 || COMPILE_TEST
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 4411a2a124d7..38354e701811 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_RESET_GPIO) += reset-gpio.o
 obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
 obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
 obj-$(CONFIG_RESET_IMX8MP_AUDIOMIX) += reset-imx8mp-audiomix.o
+obj-$(CONFIG_RESET_IMX8ULP_SIM) += reset-imx8ulp-sim.o
 obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
 obj-$(CONFIG_RESET_K210) += reset-k210.o
 obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
diff --git a/drivers/reset/reset-imx8ulp-sim.c b/drivers/reset/reset-imx8ulp-sim.c
new file mode 100644
index 000000000000..04ff11d41e10
--- /dev/null
+++ b/drivers/reset/reset-imx8ulp-sim.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2024 NXP
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+#include <linux/of_platform.h>
+
+#define IMX8ULP_SIM_RESET_MIPI_DSI_RST_DPI_N	0
+#define IMX8ULP_SIM_RESET_MIPI_DSI_RST_ESC_N	1
+#define IMX8ULP_SIM_RESET_MIPI_DSI_RST_BYTE_N	2
+
+#define IMX8ULP_SIM_RESET_NUM 3
+
+#define AVD_SIM_SYSCTRL0        0x8
+
+struct imx8ulp_sim_reset {
+	struct reset_controller_dev     rcdev;
+	struct regmap                   *regmap;
+};
+
+static const u32 imx8ulp_sim_reset_bits[IMX8ULP_SIM_RESET_NUM] = {
+	[IMX8ULP_SIM_RESET_MIPI_DSI_RST_DPI_N] = BIT(3),
+	[IMX8ULP_SIM_RESET_MIPI_DSI_RST_ESC_N] = BIT(4),
+	[IMX8ULP_SIM_RESET_MIPI_DSI_RST_BYTE_N] = BIT(5),
+};
+
+static inline struct imx8ulp_sim_reset *
+to_imx8ulp_sim_reset(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct imx8ulp_sim_reset, rcdev);
+}
+
+static int imx8ulp_sim_reset_assert(struct reset_controller_dev *rcdev,
+				    unsigned long id)
+{
+	struct imx8ulp_sim_reset *simr = to_imx8ulp_sim_reset(rcdev);
+	const u32 bit = imx8ulp_sim_reset_bits[id];
+
+	return regmap_update_bits(simr->regmap, AVD_SIM_SYSCTRL0, bit, 0);
+}
+
+static int imx8ulp_sim_reset_deassert(struct reset_controller_dev *rcdev,
+				      unsigned long id)
+{
+	struct imx8ulp_sim_reset *simr = to_imx8ulp_sim_reset(rcdev);
+	const u32 bit = imx8ulp_sim_reset_bits[id];
+
+	return regmap_update_bits(simr->regmap, AVD_SIM_SYSCTRL0, bit, bit);
+}
+
+static const struct reset_control_ops imx8ulp_sim_reset_ops = {
+	.assert         = imx8ulp_sim_reset_assert,
+	.deassert       = imx8ulp_sim_reset_deassert,
+};
+
+static const struct of_device_id imx8ulp_sim_reset_dt_ids[] = {
+	{ .compatible = "nxp,imx8ulp-avd-sim-reset", },
+	{ /* sentinel */ },
+};
+
+static int imx8ulp_sim_reset_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct imx8ulp_sim_reset *simr;
+	int ret;
+
+	simr = devm_kzalloc(dev, sizeof(*simr), GFP_KERNEL);
+	if (!simr)
+		return -ENOMEM;
+
+	simr->regmap = syscon_node_to_regmap(dev->of_node);
+	if (IS_ERR(simr->regmap))
+		return dev_err_probe(&pdev->dev, PTR_ERR(simr->regmap),
+				     "failed to get regmap\n");
+
+	simr->rcdev.owner = THIS_MODULE;
+	simr->rcdev.nr_resets = IMX8ULP_SIM_RESET_NUM;
+	simr->rcdev.ops = &imx8ulp_sim_reset_ops;
+	simr->rcdev.of_node = dev->of_node;
+
+	ret = devm_of_platform_populate(dev);
+	if (ret)
+		return ret;
+
+	return devm_reset_controller_register(dev, &simr->rcdev);
+}
+
+static struct platform_driver imx8ulp_sim_reset_driver = {
+	.probe  = imx8ulp_sim_reset_probe,
+	.driver = {
+		.name           = KBUILD_MODNAME,
+		.of_match_table = imx8ulp_sim_reset_dt_ids,
+	},
+};
+module_platform_driver(imx8ulp_sim_reset_driver);
+
+MODULE_AUTHOR("Liu Ying <victor.liu@....com>");
+MODULE_DESCRIPTION("NXP i.MX8ULP System Integration Module Reset driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1