--- /dev/null
+Pistachio Reset Controller
+=============================================================================
+
+This binding describes a reset controller device that is used to enable and
+disable individual IP blocks within the Pistachio SoC using "soft reset"
+control bits found in the Pistachio SoC top level registers.
+
+The actual action taken when soft reset is asserted is hardware dependent.
+However, when asserted it may not be possible to access the hardware's
+registers, and following an assert/deassert sequence the hardware's previous
+state may no longer be valid.
+
+Please refer to Documentation/devicetree/bindings/reset/reset.txt
+for common reset controller binding usage.
+
+Required properties:
+
+- compatible: Contains "img,pistachio-reset"
+
+- #reset-cells: Contains 1
+
+Example:
+
+ cr_periph: clk@18148000 {
+ compatible = "img,pistachio-cr-periph", "syscon", "simple-mfd";
+ reg = <0x18148000 0x1000>;
+ clocks = <&clk_periph PERIPH_CLK_SYS>;
+ clock-names = "sys";
+ #clock-cells = <1>;
+
+ pistachio_reset: reset-controller {
+ compatible = "img,pistachio-reset";
+ #reset-cells = <1>;
+ };
+ };
+
+Specifying reset control of devices
+=======================================
+
+Device nodes should specify the reset channel required in their "resets"
+property, containing a phandle to the pistachio reset device node and an
+index specifying which reset to use, as described in
+Documentation/devicetree/bindings/reset/reset.txt.
+
+Example:
+
+ spdif_out: spdif-out@18100d00 {
+ ...
+ resets = <&pistachio_reset PISTACHIO_RESET_SPDIF_OUT>;
+ reset-names = "rst";
+ ...
+ };
+
+Macro definitions for the supported resets can be found in:
+include/dt-bindings/reset/pistachio-resets.h
obj-$(CONFIG_ARCH_LPC18XX) += reset-lpc18xx.o
obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
+obj-$(CONFIG_MACH_PISTACHIO) += reset-pistachio.o
obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
obj-$(CONFIG_ARCH_STI) += sti/
obj-$(CONFIG_ARCH_HISI) += hisilicon/
static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
const struct of_phandle_args *reset_spec)
{
- if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
- return -EINVAL;
-
if (reset_spec->args[0] >= rcdev->nr_resets)
return -EINVAL;
struct reset_control *of_reset_control_get_by_index(struct device_node *node,
int index)
{
- struct reset_control *rstc = ERR_PTR(-EPROBE_DEFER);
+ struct reset_control *rstc;
struct reset_controller_dev *r, *rcdev;
struct of_phandle_args args;
int rstc_id;
return ERR_PTR(-EPROBE_DEFER);
}
+ if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
+ mutex_unlock(&reset_controller_list_mutex);
+ return ERR_PTR(-EINVAL);
+ }
+
rstc_id = rcdev->of_xlate(rcdev, &args);
if (rstc_id < 0) {
mutex_unlock(&reset_controller_list_mutex);
return 0;
}
-static struct reset_control_ops hi6220_reset_ops = {
+static const struct reset_control_ops hi6220_reset_ops = {
.assert = hi6220_reset_assert,
.deassert = hi6220_reset_deassert,
};
data->rc_dev.ops = &hi6220_reset_ops;
data->rc_dev.of_node = pdev->dev.of_node;
- reset_controller_register(&data->rc_dev);
-
- return 0;
+ return reset_controller_register(&data->rc_dev);
}
static const struct of_device_id hi6220_reset_match[] = {
return !!(val & BIT(id));
}
-static struct reset_control_ops ath79_reset_ops = {
+static const struct reset_control_ops ath79_reset_ops = {
.assert = ath79_reset_assert,
.deassert = ath79_reset_deassert,
.status = ath79_reset_status,
return 0;
}
-static struct reset_control_ops berlin_reset_ops = {
+static const struct reset_control_ops berlin_reset_ops = {
.reset = berlin_reset_reset,
};
{
unsigned offset, bit;
- if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
- return -EINVAL;
-
offset = reset_spec->args[0];
bit = reset_spec->args[1];
return !(readl(rc->base + offset) & bit);
}
-static struct reset_control_ops lpc18xx_rgu_ops = {
+static const struct reset_control_ops lpc18xx_rgu_ops = {
.reset = lpc18xx_rgu_reset,
.assert = lpc18xx_rgu_assert,
.deassert = lpc18xx_rgu_deassert,
--- /dev/null
+/*
+ * Pistachio SoC Reset Controller driver
+ *
+ * Copyright (C) 2015 Imagination Technologies Ltd.
+ *
+ * Author: Damien Horsley <Damien.Horsley@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+
+#include <dt-bindings/reset/pistachio-resets.h>
+
+#define PISTACHIO_SOFT_RESET 0
+
+struct pistachio_reset_data {
+ struct reset_controller_dev rcdev;
+ struct regmap *periph_regs;
+};
+
+static inline int pistachio_reset_shift(unsigned long id)
+{
+ switch (id) {
+ case PISTACHIO_RESET_I2C0:
+ case PISTACHIO_RESET_I2C1:
+ case PISTACHIO_RESET_I2C2:
+ case PISTACHIO_RESET_I2C3:
+ case PISTACHIO_RESET_I2S_IN:
+ case PISTACHIO_RESET_PRL_OUT:
+ case PISTACHIO_RESET_SPDIF_OUT:
+ case PISTACHIO_RESET_SPI:
+ case PISTACHIO_RESET_PWM_PDM:
+ case PISTACHIO_RESET_UART0:
+ case PISTACHIO_RESET_UART1:
+ case PISTACHIO_RESET_QSPI:
+ case PISTACHIO_RESET_MDC:
+ case PISTACHIO_RESET_SDHOST:
+ case PISTACHIO_RESET_ETHERNET:
+ case PISTACHIO_RESET_IR:
+ case PISTACHIO_RESET_HASH:
+ case PISTACHIO_RESET_TIMER:
+ return id;
+ case PISTACHIO_RESET_I2S_OUT:
+ case PISTACHIO_RESET_SPDIF_IN:
+ case PISTACHIO_RESET_EVT:
+ return id + 6;
+ case PISTACHIO_RESET_USB_H:
+ case PISTACHIO_RESET_USB_PR:
+ case PISTACHIO_RESET_USB_PHY_PR:
+ case PISTACHIO_RESET_USB_PHY_PON:
+ return id + 7;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int pistachio_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct pistachio_reset_data *rd;
+ u32 mask;
+ int shift;
+
+ rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
+ shift = pistachio_reset_shift(id);
+ if (shift < 0)
+ return shift;
+ mask = BIT(shift);
+
+ return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
+ mask, mask);
+}
+
+static int pistachio_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct pistachio_reset_data *rd;
+ u32 mask;
+ int shift;
+
+ rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
+ shift = pistachio_reset_shift(id);
+ if (shift < 0)
+ return shift;
+ mask = BIT(shift);
+
+ return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
+ mask, 0);
+}
+
+static const struct reset_control_ops pistachio_reset_ops = {
+ .assert = pistachio_reset_assert,
+ .deassert = pistachio_reset_deassert,
+};
+
+static int pistachio_reset_probe(struct platform_device *pdev)
+{
+ struct pistachio_reset_data *rd;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = pdev->dev.of_node;
+
+ rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL);
+ if (!rd)
+ return -ENOMEM;
+
+ rd->periph_regs = syscon_node_to_regmap(np->parent);
+ if (IS_ERR(rd->periph_regs))
+ return PTR_ERR(rd->periph_regs);
+
+ rd->rcdev.owner = THIS_MODULE;
+ rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1;
+ rd->rcdev.ops = &pistachio_reset_ops;
+ rd->rcdev.of_node = np;
+
+ return reset_controller_register(&rd->rcdev);
+}
+
+static int pistachio_reset_remove(struct platform_device *pdev)
+{
+ struct pistachio_reset_data *data = platform_get_drvdata(pdev);
+
+ reset_controller_unregister(&data->rcdev);
+
+ return 0;
+}
+
+static const struct of_device_id pistachio_reset_dt_ids[] = {
+ { .compatible = "img,pistachio-reset", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, pistachio_reset_dt_ids);
+
+static struct platform_driver pistachio_reset_driver = {
+ .probe = pistachio_reset_probe,
+ .remove = pistachio_reset_remove,
+ .driver = {
+ .name = "pistachio-reset",
+ .of_match_table = pistachio_reset_dt_ids,
+ },
+};
+module_platform_driver(pistachio_reset_driver);
+
+MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>");
+MODULE_DESCRIPTION("Pistacho Reset Controller Driver");
+MODULE_LICENSE("GPL v2");
return !(reg & BIT(offset));
}
-static struct reset_control_ops socfpga_reset_ops = {
+static const struct reset_control_ops socfpga_reset_ops = {
.assert = socfpga_reset_assert,
.deassert = socfpga_reset_deassert,
.status = socfpga_reset_status,
return 0;
}
-static struct reset_control_ops sunxi_reset_ops = {
+static const struct reset_control_ops sunxi_reset_ops = {
.assert = sunxi_reset_assert,
.deassert = sunxi_reset_deassert,
};
return !!(reg & BIT(offset));
}
-static struct reset_control_ops zynq_reset_ops = {
+static const struct reset_control_ops zynq_reset_ops = {
.assert = zynq_reset_assert,
.deassert = zynq_reset_deassert,
.status = zynq_reset_status,
return rst->active_low ? !ret_val : !!ret_val;
}
-static struct reset_control_ops syscfg_reset_ops = {
+static const struct reset_control_ops syscfg_reset_ops = {
.reset = syscfg_reset_dev,
.assert = syscfg_reset_assert,
.deassert = syscfg_reset_deassert,
--- /dev/null
+/*
+ * This header provides constants for the reset controller
+ * present in the Pistachio SoC
+ */
+
+#ifndef _PISTACHIO_RESETS_H
+#define _PISTACHIO_RESETS_H
+
+#define PISTACHIO_RESET_I2C0 0
+#define PISTACHIO_RESET_I2C1 1
+#define PISTACHIO_RESET_I2C2 2
+#define PISTACHIO_RESET_I2C3 3
+#define PISTACHIO_RESET_I2S_IN 4
+#define PISTACHIO_RESET_PRL_OUT 5
+#define PISTACHIO_RESET_SPDIF_OUT 6
+#define PISTACHIO_RESET_SPI 7
+#define PISTACHIO_RESET_PWM_PDM 8
+#define PISTACHIO_RESET_UART0 9
+#define PISTACHIO_RESET_UART1 10
+#define PISTACHIO_RESET_QSPI 11
+#define PISTACHIO_RESET_MDC 12
+#define PISTACHIO_RESET_SDHOST 13
+#define PISTACHIO_RESET_ETHERNET 14
+#define PISTACHIO_RESET_IR 15
+#define PISTACHIO_RESET_HASH 16
+#define PISTACHIO_RESET_TIMER 17
+#define PISTACHIO_RESET_I2S_OUT 18
+#define PISTACHIO_RESET_SPDIF_IN 19
+#define PISTACHIO_RESET_EVT 20
+#define PISTACHIO_RESET_USB_H 21
+#define PISTACHIO_RESET_USB_PR 22
+#define PISTACHIO_RESET_USB_PHY_PR 23
+#define PISTACHIO_RESET_USB_PHY_PON 24
+#define PISTACHIO_RESET_MAX 24
+
+#endif
* @nr_resets: number of reset controls in this reset controller device
*/
struct reset_controller_dev {
- struct reset_control_ops *ops;
+ const struct reset_control_ops *ops;
struct module *owner;
struct list_head list;
struct device_node *of_node;
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