[PATCH v3 2/5] reset: socfpga: use the reset-simple driver

From: Philipp Zabel
Date: Wed Aug 16 2017 - 05:47:44 EST

Add reset line status readback, inverted status support, and socfpga
device tree quirks to the simple reset driver, and use it to replace
the socfpga driver.

Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
---
- Rename "status_inverted" properties to "status_active_low".
- Add reg_offset and nr_reset override to struct reset_simple_devdata.
- Drop socfpga special case, instead check "altr,modrst-offset" device
tree property if a default reg_offset is set.
---
drivers/reset/Kconfig | 10 +--
drivers/reset/Makefile | 1 -
drivers/reset/reset-simple.c | 50 +++++++++++++-
drivers/reset/reset-simple.h | 4 ++
drivers/reset/reset-socfpga.c | 154 ------------------------------------------
5 files changed, 55 insertions(+), 164 deletions(-)
delete mode 100644 drivers/reset/reset-socfpga.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index f7ba01a71daee..78a8f6057985b 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -70,19 +70,13 @@ config RESET_PISTACHIO

config RESET_SIMPLE
bool "Simple Reset Controller Driver" if COMPILE_TEST
- default ARCH_SUNXI
+ default ARCH_SOCFPGA || ARCH_SUNXI
help
This enables a simple reset controller driver for reset lines that
that can be asserted and deasserted by toggling bits in a contiguous,
exclusive register space.

- Currently this driver supports Allwinner SoCs.
-
-config RESET_SOCFPGA
- bool "SoCFPGA Reset Driver" if COMPILE_TEST
- default ARCH_SOCFPGA
- help
- This enables the reset controller driver for Altera SoCFPGAs.
+ Currently this driver supports Altera SoCFPGAs and Allwinner SoCs.

config RESET_STM32
bool "STM32 Reset Driver" if COMPILE_TEST
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index ab4af99c3dfdc..25f5f722dec01 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -12,7 +12,6 @@ obj-$(CONFIG_RESET_MESON) += reset-meson.o
obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
-obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
obj-$(CONFIG_RESET_STM32) += reset-stm32.o
obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c
index 70c57c0758c39..84b08ce4def01 100644
--- a/drivers/reset/reset-simple.c
+++ b/drivers/reset/reset-simple.c
@@ -68,25 +68,58 @@ static int reset_simple_deassert(struct reset_controller_dev *rcdev,
return reset_simple_set(rcdev, id, false);
}

+static int reset_simple_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct reset_simple_data *data = to_reset_simple_data(rcdev);
+ int reg_width = sizeof(u32);
+ int bank = id / (reg_width * BITS_PER_BYTE);
+ int offset = id % (reg_width * BITS_PER_BYTE);
+ u32 reg;
+
+ reg = readl(data->membase + (bank * reg_width));
+
+ return !(reg & BIT(offset)) ^ !data->status_active_low;
+}
+
const struct reset_control_ops reset_simple_ops = {
.assert = reset_simple_assert,
.deassert = reset_simple_deassert,
+ .status = reset_simple_status,
};

/**
* struct reset_simple_devdata - simple reset controller properties
+ * @reg_offset: offset between base address and first reset register.
+ * @nr_resets: number of resets. If not set, default to resource size in bits.
* @active_low: if true, bits are cleared to assert the reset. Otherwise, bits
* are set to assert the reset.
+ * @status_active_low: if true, bits read back as cleared while the reset is
+ * asserted. Otherwise, bits read back as set while the
+ * reset is asserted.
*/
struct reset_simple_devdata {
+ u32 reg_offset;
+ u32 nr_resets;
bool active_low;
+ bool status_active_low;
+};
+
+#define SOCFPGA_NR_BANKS 8
+
+static const struct reset_simple_devdata reset_simple_socfpga = {
+ .reg_offset = 0x10,
+ .nr_resets = SOCFPGA_NR_BANKS * 32,
+ .status_active_low = true,
};

static const struct reset_simple_devdata reset_simple_active_low = {
.active_low = true,
+ .status_active_low = true,
};

static const struct of_device_id reset_simple_dt_ids[] = {
+ { .compatible = "altr,rst-mgr", .data = &reset_simple_socfpga },
{ .compatible = "allwinner,sun6i-a31-clock-reset",
.data = &reset_simple_active_low },
{ /* sentinel */ },
@@ -118,8 +151,23 @@ static int reset_simple_probe(struct platform_device *pdev)
data->rcdev.ops = &reset_simple_ops;
data->rcdev.of_node = dev->of_node;

- if (devdata)
+ if (devdata) {
+ u32 reg_offset = devdata->reg_offset;
+
+ if (reg_offset &&
+ of_property_read_u32(dev->of_node, "altr,modrst-offset",
+ &reg_offset)) {
+ dev_warn(dev,
+ "missing altr,modrst-offset property, assuming 0x%x!\n",
+ reg_offset);
+ }
+
+ data->membase += reg_offset;
+ if (devdata->nr_resets)
+ data->rcdev.nr_resets = devdata->nr_resets;
data->active_low = devdata->active_low;
+ data->status_active_low = devdata->status_active_low;
+ }

return devm_reset_controller_register(dev, &data->rcdev);
}
diff --git a/drivers/reset/reset-simple.h b/drivers/reset/reset-simple.h
index 39af2014b5f12..8a496022baeff 100644
--- a/drivers/reset/reset-simple.h
+++ b/drivers/reset/reset-simple.h
@@ -28,12 +28,16 @@
* @active_low: if true, bits are cleared to assert the reset. Otherwise, bits
* are set to assert the reset. Note that this says nothing about
* the voltage level of the actual reset line.
+ * @status_active_low: if true, bits read back as cleared while the reset is
+ * asserted. Otherwise, bits read back as set while the
+ * reset is asserted.
*/
struct reset_simple_data {
spinlock_t lock;
void __iomem *membase;
struct reset_controller_dev rcdev;
bool active_low;
+ bool status_active_low;
};

extern const struct reset_control_ops reset_simple_ops;
diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
deleted file mode 100644
index 07224c0198920..0000000000000
--- a/drivers/reset/reset-socfpga.c
+++ /dev/null
@@ -1,154 +0,0 @@
-/*
- * Socfpga Reset Controller Driver
- *
- * Copyright 2014 Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
- *
- * based on
- * Allwinner SoCs Reset Controller driver
- *
- * Copyright 2013 Maxime Ripard
- *
- * Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- */
-
-#include <linux/err.h>
-#include <linux/io.h>
-#include <linux/init.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <linux/reset-controller.h>
-#include <linux/spinlock.h>
-#include <linux/types.h>
-
-#define BANK_INCREMENT 4
-#define NR_BANKS 8
-
-struct socfpga_reset_data {
- spinlock_t lock;
- void __iomem *membase;
- struct reset_controller_dev rcdev;
-};
-
-static int socfpga_reset_assert(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- struct socfpga_reset_data *data = container_of(rcdev,
- struct socfpga_reset_data,
- rcdev);
- int bank = id / BITS_PER_LONG;
- int offset = id % BITS_PER_LONG;
- unsigned long flags;
- u32 reg;
-
- spin_lock_irqsave(&data->lock, flags);
-
- reg = readl(data->membase + (bank * BANK_INCREMENT));
- writel(reg | BIT(offset), data->membase + (bank * BANK_INCREMENT));
- spin_unlock_irqrestore(&data->lock, flags);
-
- return 0;
-}
-
-static int socfpga_reset_deassert(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- struct socfpga_reset_data *data = container_of(rcdev,
- struct socfpga_reset_data,
- rcdev);
-
- int bank = id / BITS_PER_LONG;
- int offset = id % BITS_PER_LONG;
- unsigned long flags;
- u32 reg;
-
- spin_lock_irqsave(&data->lock, flags);
-
- reg = readl(data->membase + (bank * BANK_INCREMENT));
- writel(reg & ~BIT(offset), data->membase + (bank * BANK_INCREMENT));
-
- spin_unlock_irqrestore(&data->lock, flags);
-
- return 0;
-}
-
-static int socfpga_reset_status(struct reset_controller_dev *rcdev,
- unsigned long id)
-{
- struct socfpga_reset_data *data = container_of(rcdev,
- struct socfpga_reset_data, rcdev);
- int bank = id / BITS_PER_LONG;
- int offset = id % BITS_PER_LONG;
- u32 reg;
-
- reg = readl(data->membase + (bank * BANK_INCREMENT));
-
- return !(reg & BIT(offset));
-}
-
-static const struct reset_control_ops socfpga_reset_ops = {
- .assert = socfpga_reset_assert,
- .deassert = socfpga_reset_deassert,
- .status = socfpga_reset_status,
-};
-
-static int socfpga_reset_probe(struct platform_device *pdev)
-{
- struct socfpga_reset_data *data;
- struct resource *res;
- struct device *dev = &pdev->dev;
- struct device_node *np = dev->of_node;
- u32 modrst_offset;
-
- /*
- * The binding was mainlined without the required property.
- * Do not continue, when we encounter an old DT.
- */
- if (!of_find_property(pdev->dev.of_node, "#reset-cells", NULL)) {
- dev_err(&pdev->dev, "%s missing #reset-cells property\n",
- pdev->dev.of_node->full_name);
- return -EINVAL;
- }
-
- data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- data->membase = devm_ioremap_resource(&pdev->dev, res);
- if (IS_ERR(data->membase))
- return PTR_ERR(data->membase);
-
- if (of_property_read_u32(np, "altr,modrst-offset", &modrst_offset)) {
- dev_warn(dev, "missing altr,modrst-offset property, assuming 0x10!\n");
- modrst_offset = 0x10;
- }
- data->membase += modrst_offset;
-
- spin_lock_init(&data->lock);
-
- data->rcdev.owner = THIS_MODULE;
- data->rcdev.nr_resets = NR_BANKS * BITS_PER_LONG;
- data->rcdev.ops = &socfpga_reset_ops;
- data->rcdev.of_node = pdev->dev.of_node;
-
- return devm_reset_controller_register(dev, &data->rcdev);
-}
-
-static const struct of_device_id socfpga_reset_dt_ids[] = {
- { .compatible = "altr,rst-mgr", },
- { /* sentinel */ },
-};
-
-static struct platform_driver socfpga_reset_driver = {
- .probe = socfpga_reset_probe,
- .driver = {
- .name = "socfpga-reset",
- .of_match_table = socfpga_reset_dt_ids,
- },
-};
-builtin_platform_driver(socfpga_reset_driver);
--
2.11.0