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Subject[PATCH 2/3] reset: mchp: sparx5: add switch reset driver
Date
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
---
drivers/reset/Kconfig | 8 ++
drivers/reset/Makefile | 1 +
drivers/reset/reset-microchip-sparx5.c | 145 +++++++++++++++++++++++++
3 files changed, 154 insertions(+)
create mode 100644 drivers/reset/reset-microchip-sparx5.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 71ab75a46491..05c240c47a8a 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -101,6 +101,14 @@ config RESET_LPC18XX
help
This enables the reset controller driver for NXP LPC18xx/43xx SoCs.

+config RESET_MCHP_SPARX5
+ bool "Microchip Sparx5 reset driver"
+ depends on HAS_IOMEM || COMPILE_TEST
+ default y if SPARX5_SWITCH
+ select MFD_SYSCON
+ help
+ This driver supports switch core reset for the Microchip Sparx5 SoC.
+
config RESET_MESON
tristate "Meson Reset Driver"
depends on ARCH_MESON || COMPILE_TEST
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 1054123fd187..341fd9ab4bf6 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o
obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
+obj-$(CONFIG_RESET_MCHP_SPARX5) += reset-microchip-sparx5.o
obj-$(CONFIG_RESET_MESON) += reset-meson.o
obj-$(CONFIG_RESET_MESON_AUDIO_ARB) += reset-meson-audio-arb.o
obj-$(CONFIG_RESET_NPCM) += reset-npcm.o
diff --git a/drivers/reset/reset-microchip-sparx5.c b/drivers/reset/reset-microchip-sparx5.c
new file mode 100644
index 000000000000..bb636ebd22d2
--- /dev/null
+++ b/drivers/reset/reset-microchip-sparx5.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Microchip Sparx5 Switch Reset driver
+ *
+ * Copyright (c) 2020 Microchip Technology Inc. and its subsidiaries.
+ *
+ * The Sparx5 Chip Register Model can be browsed at this location:
+ * https://github.com/microchip-ung/sparx-5_reginfo
+ */
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+#define PROTECT_REG 0x84
+#define PROTECT_BIT BIT(10)
+#define SOFT_RESET_REG 0x08
+#define SOFT_RESET_BIT BIT(1)
+
+struct mchp_reset_context {
+ struct device *dev;
+ struct regmap *cpu_ctrl;
+ struct regmap *gcb_ctrl;
+ struct reset_controller_dev reset_ctrl;
+};
+
+static u32 sparx5_read_soft_rst(struct mchp_reset_context *ctx)
+{
+ u32 val;
+
+ regmap_read(ctx->gcb_ctrl, SOFT_RESET_REG, &val);
+ return val;
+}
+
+static int sparx5_switch_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct mchp_reset_context *ctx =
+ container_of(rcdev, struct mchp_reset_context, reset_ctrl);
+ u32 val;
+
+ /* Make sure the core is PROTECTED from reset */
+ regmap_update_bits(ctx->cpu_ctrl, PROTECT_REG, PROTECT_BIT, PROTECT_BIT);
+
+ dev_info(ctx->dev, "soft reset of switchcore\n");
+
+ /* Start soft reset */
+ regmap_write(ctx->gcb_ctrl, SOFT_RESET_REG, SOFT_RESET_BIT);
+
+ /* Wait for soft reset done */
+ return read_poll_timeout(sparx5_read_soft_rst, val,
+ (val & SOFT_RESET_BIT) == 0,
+ 1, 100, false,
+ ctx);
+}
+
+static const struct reset_control_ops sparx5_reset_ops = {
+ .reset = sparx5_switch_reset,
+};
+
+static int mchp_sparx5_reset_config(struct platform_device *pdev,
+ struct mchp_reset_context *ctx)
+{
+ struct device_node *dn = pdev->dev.of_node;
+ struct regmap *cpu_ctrl, *gcb_ctrl;
+ struct device_node *syscon_np;
+ int err;
+
+ syscon_np = of_parse_phandle(dn, "syscons", 0);
+ if (!syscon_np)
+ return -ENODEV;
+ cpu_ctrl = syscon_node_to_regmap(syscon_np);
+ if (IS_ERR(cpu_ctrl))
+ goto err_cpu;
+ of_node_put(syscon_np);
+
+ syscon_np = of_parse_phandle(dn, "syscons", 1);
+ if (!syscon_np)
+ return -ENODEV;
+ gcb_ctrl = syscon_node_to_regmap(syscon_np);
+ if (IS_ERR(gcb_ctrl))
+ goto err_gcb;
+ of_node_put(syscon_np);
+
+ ctx->cpu_ctrl = cpu_ctrl;
+ ctx->gcb_ctrl = gcb_ctrl;
+
+ ctx->reset_ctrl.owner = THIS_MODULE;
+ ctx->reset_ctrl.nr_resets = 1;
+ ctx->reset_ctrl.ops = &sparx5_reset_ops;
+ ctx->reset_ctrl.of_node = dn;
+
+ err = devm_reset_controller_register(&pdev->dev, &ctx->reset_ctrl);
+ if (err)
+ dev_err(&pdev->dev, "could not register reset controller\n");
+ pr_info("%s:%d\n", __func__, __LINE__);
+ return err;
+err_cpu:
+ of_node_put(syscon_np);
+ dev_err(&pdev->dev, "No cpu syscon map\n");
+ return PTR_ERR(cpu_ctrl);
+err_gcb:
+ of_node_put(syscon_np);
+ dev_err(&pdev->dev, "No gcb syscon map\n");
+ return PTR_ERR(gcb_ctrl);
+}
+
+static int mchp_sparx5_reset_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mchp_reset_context *ctx;
+
+ pr_info("%s:%d\n", __func__, __LINE__);
+ ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+ ctx->dev = dev;
+ return mchp_sparx5_reset_config(pdev, ctx);
+}
+
+static const struct of_device_id mchp_sparx5_reset_of_match[] = {
+ {
+ .compatible = "microchip,sparx5-switch-reset",
+ },
+ { /*sentinel*/ }
+};
+
+static struct platform_driver mchp_sparx5_reset_driver = {
+ .probe = mchp_sparx5_reset_probe,
+ .driver = {
+ .name = "sparx5-switch-reset",
+ .of_match_table = mchp_sparx5_reset_of_match,
+ },
+};
+
+static int __init mchp_sparx5_reset_init(void)
+{
+ return platform_driver_register(&mchp_sparx5_reset_driver);
+}
+
+postcore_initcall(mchp_sparx5_reset_init);
--
2.29.2
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