On Mon, Apr 17, 2017 at 9:29 PM, Hauke Mehrtens <hauke@xxxxxxxxxx> wrote:
> From: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
>
> The reset controllers (on xRX200 and newer SoCs have two of them) are
> provided by the RCU module. This was initially implemented as a simple
> reset controller. However, the RCU module provides more functionality
> (ethernet GPHYs, USB PHY, etc.), which makes it a MFD device.
> The old reset controller driver implementation from
> arch/mips/lantiq/xway/reset.c did not honor this fact.
>
> For some devices the request and the status bits are different.
>
> Signed-off-by: Hauke Mehrtens <hauke@xxxxxxxxxx>
I think you should CC the reset controller framework maintainer
(Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>) as well
> ---
> .../devicetree/bindings/reset/lantiq,rcu-reset.txt | 43 ++++
> arch/mips/lantiq/xway/reset.c | 68 ------
> drivers/reset/Kconfig | 6 +
> drivers/reset/Makefile | 1 +
> drivers/reset/reset-lantiq-rcu.c | 231 +++++++++++++++++++++
> 5 files changed, 281 insertions(+), 68 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt
> create mode 100644 drivers/reset/reset-lantiq-rcu.c
>
> diff --git a/Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt b/Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt
> new file mode 100644
> index 000000000000..7f097d16bbb7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reset/lantiq,rcu-reset.txt
> @@ -0,0 +1,43 @@
> +Lantiq XWAY SoC RCU reset controller binding
> +============================================
> +
> +This binding describes a reset-controller found on the RCU module on Lantiq
> +XWAY SoCs.
> +
> +
> +-------------------------------------------------------------------------------
> +Required properties (controller (parent) node):
> +- compatible : Should be "lantiq,rcu-reset"
> +- lantiq,rcu-syscon : A phandle to the RCU syscon, the reset register
> + offset and the status register offset.
> +- #reset-cells : Specifies the number of cells needed to encode the
> + reset line, should be 1.
> +
> +Optional properties:
> +- reset-status : The request status bit. For some bits the request bit
> + and the status bit are different. This is depending
> + on the SoC. If the reset-status bit does not match
> + the reset-request bit, put the reset number into the
> + reset-request property and the status bit at the same
> + index into the reset-status property. If no
> + reset-request bit is given here, the driver assume
> + status and request bit are the same.
> +- reset-request : The reset request bit, to map it to the reset-status
> + bit.
> +
> +
> +-------------------------------------------------------------------------------
> +Example for the reset-controllers on the xRX200 SoCs:
> + rcu_reset0: rcu_reset {
> + compatible = "lantiq,rcu-reset";
> + lantiq,rcu-syscon = <&rcu0 0x10 0x14>;
> + #reset-cells = <1>;
> + reset-request = <31>, <29>, <21>, <19>, <16>, <12>;
> + reset-status = <30>, <28>, <16>, <25>, <5>, <24>;
> + };
> +
> + rcu_reset1: rcu_reset {
> + compatible = "lantiq,rcu-reset";
> + lantiq,rcu-syscon = <&rcu0 0x48 0x24>;
> + #reset-cells = <1>;
> + };
> diff --git a/arch/mips/lantiq/xway/reset.c b/arch/mips/lantiq/xway/reset.c
> index 2dedcf939901..5cb9309b0047 100644
> --- a/arch/mips/lantiq/xway/reset.c
> +++ b/arch/mips/lantiq/xway/reset.c
probably a left-over of my patch: can't this
arch/mips/lantiq/xway/reset.c change go into PATCH #13 as well?
> @@ -194,74 +194,6 @@ int xrx200_gphy_boot(struct device *dev, unsigned int id, dma_addr_t dev_addr)
> return 0;
> }
>
> -/* reset a io domain for u micro seconds */
> -void ltq_reset_once(unsigned int module, ulong u)
> -{
> - ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) | module, RCU_RST_REQ);
> - udelay(u);
> - ltq_rcu_w32(ltq_rcu_r32(RCU_RST_REQ) & ~module, RCU_RST_REQ);
> -}
> -
> -static int ltq_assert_device(struct reset_controller_dev *rcdev,
> - unsigned long id)
> -{
> - u32 val;
> -
> - if (id < 8)
> - return -1;
> -
> - val = ltq_rcu_r32(RCU_RST_REQ);
> - val |= BIT(id);
> - ltq_rcu_w32(val, RCU_RST_REQ);
> -
> - return 0;
> -}
> -
> -static int ltq_deassert_device(struct reset_controller_dev *rcdev,
> - unsigned long id)
> -{
> - u32 val;
> -
> - if (id < 8)
> - return -1;
> -
> - val = ltq_rcu_r32(RCU_RST_REQ);
> - val &= ~BIT(id);
> - ltq_rcu_w32(val, RCU_RST_REQ);
> -
> - return 0;
> -}
> -
> -static int ltq_reset_device(struct reset_controller_dev *rcdev,
> - unsigned long id)
> -{
> - ltq_assert_device(rcdev, id);
> - return ltq_deassert_device(rcdev, id);
> -}
> -
> -static const struct reset_control_ops reset_ops = {
> - .reset = ltq_reset_device,
> - .assert = ltq_assert_device,
> - .deassert = ltq_deassert_device,
> -};
> -
> -static struct reset_controller_dev reset_dev = {
> - .ops = &reset_ops,
> - .owner = THIS_MODULE,
> - .nr_resets = 32,
> - .of_reset_n_cells = 1,
> -};
> -
> -void ltq_rst_init(void)
> -{
> - reset_dev.of_node = of_find_compatible_node(NULL, NULL,
> - "lantiq,xway-reset");
> - if (!reset_dev.of_node)
> - pr_err("Failed to find reset controller node");
> - else
> - reset_controller_register(&reset_dev);
> -}
> -
> static void ltq_machine_restart(char *command)
> {
> u32 val = ltq_rcu_r32(RCU_RST_REQ);
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index f4cdfe94b9ec..8962ba44248c 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -27,6 +27,12 @@ config RESET_BERLIN
> help
> This enables the reset controller driver for Marvell Berlin SoCs.
>
> +config RESET_LANTIQ_RCU
> + bool "Lantiq XWAY Reset Driver" if COMPILE_TEST
> + default SOC_TYPE_XWAY
> + help
> + This enables the reset controller driver for Lantiq / Intel XWAY SoCs.
> +
> config RESET_LPC18XX
> bool "LPC18xx/43xx Reset Driver" if COMPILE_TEST
> default ARCH_LPC18XX
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 2cd3f6c45165..97b0a844b849 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -4,6 +4,7 @@ obj-$(CONFIG_ARCH_STI) += sti/
> obj-$(CONFIG_ARCH_TEGRA) += tegra/
> obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
> obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
> +obj-$(CONFIG_RESET_LANTIQ_RCU) += reset-lantiq-rcu.o
> obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
> obj-$(CONFIG_RESET_MESON) += reset-meson.o
> obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
> diff --git a/drivers/reset/reset-lantiq-rcu.c b/drivers/reset/reset-lantiq-rcu.c
> new file mode 100644
> index 000000000000..6178112ca5b4
> --- /dev/null
> +++ b/drivers/reset/reset-lantiq-rcu.c
> @@ -0,0 +1,231 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + *
> + * Copyright (C) 2010 John Crispin <blogic@xxxxxxxxxxx>
> + * Copyright (C) 2013-2015 Lantiq Beteiligungs-GmbH & Co.KG
> + * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> + * Copyright (C) 2017 Hauke Mehrtens <hauke@xxxxxxxxxx>
> + */
> +
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/reset-controller.h>
> +#include <linux/of_platform.h>
> +
> +#define LANTIQ_RCU_RESET_TIMEOUT 1000000
> +
> +struct lantiq_rcu_reset_translation {
> + int request;
> + int status;
> +};
> +
> +struct lantiq_rcu_reset_priv {
> + struct reset_controller_dev rcdev;
> + struct device *dev;
> + struct regmap *regmap;
> + u32 reset_offset;
> + u32 status_offset;
> + int trans_number;
> + struct lantiq_rcu_reset_translation *trans;
> +};
> +
> +static struct lantiq_rcu_reset_priv *to_lantiq_rcu_reset_priv(
> + struct reset_controller_dev *rcdev)
> +{
> + return container_of(rcdev, struct lantiq_rcu_reset_priv, rcdev);
> +}
> +
> +static int lantiq_rcu_reset_status(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + struct lantiq_rcu_reset_priv *priv = to_lantiq_rcu_reset_priv(rcdev);
> + u32 val;
> + int ret, i;
> +
> + if (id >= rcdev->nr_resets)
> + return -EINVAL;
> +
> + for (i = 0; i < priv->trans_number; i++) {
> + if (id == priv->trans[i].request) {
> + id = priv->trans[i].status;
> + break;
> + }
> + }
> +
> + ret = regmap_read(priv->regmap, priv->status_offset, &val);
> + if (ret)
> + return ret;
> +
> + return !!(val & BIT(id));
> +}
> +
> +static int lantiq_rcu_reset_update(struct reset_controller_dev *rcdev,
> + unsigned long id, bool assert)
> +{
> + struct lantiq_rcu_reset_priv *priv = to_lantiq_rcu_reset_priv(rcdev);
> + u32 val;
> + int ret, retry = LANTIQ_RCU_RESET_TIMEOUT;
> +
> + if (id >= rcdev->nr_resets)
> + return -EINVAL;
> +
> + if (assert)
> + val = BIT(id);
> + else
> + val = 0;
> +
> + ret = regmap_update_bits(priv->regmap, priv->reset_offset, BIT(id),
> + val);
> + if (ret) {
> + dev_err(priv->dev, "Failed to set reset bit %lu\n", id);
> + return ret;
> + }
> +
> + do {} while (--retry && lantiq_rcu_reset_status(rcdev, id) != assert);
> + if (!retry) {
> + dev_err(priv->dev, "Failed to %s bit %lu\n",
> + assert ? "assert" : "deassert", id);
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static int lantiq_rcu_reset_assert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + return lantiq_rcu_reset_update(rcdev, id, true);
> +}
> +
> +static int lantiq_rcu_reset_deassert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + return lantiq_rcu_reset_update(rcdev, id, false);
> +}
> +
> +static int lantiq_rcu_reset_reset(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + int ret;
> +
> + ret = lantiq_rcu_reset_assert(rcdev, id);
> + if (ret)
> + return ret;
> +
> + return lantiq_rcu_reset_deassert(rcdev, id);
> +}
> +
> +static struct reset_control_ops lantiq_rcu_reset_ops = {
> + .assert = lantiq_rcu_reset_assert,
> + .deassert = lantiq_rcu_reset_deassert,
> + .status = lantiq_rcu_reset_status,
> + .reset = lantiq_rcu_reset_reset,
> +};
> +
> +static int lantiq_rcu_reset_of_probe(struct platform_device *pdev,
> + struct lantiq_rcu_reset_priv *priv)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + int cnt, i, ret;
> +
> + priv->regmap = syscon_regmap_lookup_by_phandle(np,
> + "lantiq,rcu-syscon");
> + if (IS_ERR(priv->regmap)) {
> + dev_err(&pdev->dev, "Failed to lookup RCU regmap\n");
> + return PTR_ERR(priv->regmap);
> + }
> +
> + if (of_property_read_u32_index(np, "lantiq,rcu-syscon", 1,
> + &priv->reset_offset)) {
> + dev_err(&pdev->dev, "Failed to get RCU reset offset\n");
> + return -EINVAL;
> + }
> +
> + if (of_property_read_u32_index(np, "lantiq,rcu-syscon", 2,
> + &priv->status_offset)) {
> + dev_err(&pdev->dev, "Failed to get RCU status offset\n");
> + return -EINVAL;
> + }
> +
> + cnt = of_property_count_elems_of_size(np, "reset-request", sizeof(u32));
> + if (cnt <= 0)
> + return 0;
> +
> + priv->trans = devm_kmalloc_array(&pdev->dev, cnt, sizeof(*priv->trans),
> + GFP_KERNEL);
> + if (!priv->trans)
> + return -ENOMEM;
> +
> + for (i = 0; i < cnt; i++) {
> + ret = of_property_read_u32_index(np, "reset-request", i,
> + &priv->trans[i].request);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "Failed to get reset-request at index %i\n",
> + i);
> + return ret;
> + }
> + ret = of_property_read_u32_index(np, "reset-status", i,
> + &priv->trans[i].status);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "Failed to get reset-status at index %i\n",
> + i);
> + return ret;
> + }
> + }
> + priv->trans_number = cnt;
> +
> + return 0;
> +}
> +
> +static int lantiq_rcu_reset_probe(struct platform_device *pdev)
> +{
> + struct lantiq_rcu_reset_priv *priv;
> + int err;
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->dev = &pdev->dev;
> + platform_set_drvdata(pdev, priv);
> +
> + err = lantiq_rcu_reset_of_probe(pdev, priv);
> + if (err)
> + return err;
> +
> + priv->rcdev.ops = &lantiq_rcu_reset_ops;
> + priv->rcdev.owner = THIS_MODULE;
> + priv->rcdev.of_node = pdev->dev.of_node;
> + priv->rcdev.of_reset_n_cells = 1;
> + priv->rcdev.nr_resets = 32;
> +
> + err = reset_controller_register(&priv->rcdev);
> + if (err)
> + return err;
> +
> + return 0;
> +}
> +
> +static const struct of_device_id lantiq_rcu_reset_dt_ids[] = {
> + { .compatible = "lantiq,rcu-reset", },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, lantiq_rcu_reset_dt_ids);
> +
> +static struct platform_driver lantiq_rcu_reset_driver = {
> + .probe = lantiq_rcu_reset_probe,
> + .driver = {
> + .name = "lantiq-rcu-reset",
> + .of_match_table = lantiq_rcu_reset_dt_ids,
> + },
> +};
> +module_platform_driver(lantiq_rcu_reset_driver);
> +
> +MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Lantiq XWAY RCU Reset Controller Driver");
> +MODULE_LICENSE("GPL");
> --
> 2.11.0
>
