Commit 4cf176e5 authored by Jim Quinlan's avatar Jim Quinlan Committed by Philipp Zabel
Browse files

reset: Add Broadcom STB RESCAL reset controller 



On BCM7216 there is a special purpose reset controller named RESCAL
(reset calibration) which is necessary for SATA and PCIe0/1 to operate
correctly. This commit adds support for such a reset controller to be
available.

Signed-off-by: default avatarJim Quinlan <jim2101024@gmail.com>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
parent f6e1405f

drivers/reset/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -49,6 +49,13 @@ config RESET_BRCMSTB 
	  This enables the reset controller driver for Broadcom STB SoCs using

	  a SUN_TOP_CTRL_SW_INIT style controller.



config RESET_BRCMSTB_RESCAL

	bool "Broadcom STB RESCAL reset controller"

	default ARCH_BRCMSTB || COMPILE_TEST

	help

	  This enables the RESCAL reset controller for SATA, PCIe0, or PCIe1 on

	  BCM7216.



config RESET_HSDK

	bool "Synopsys HSDK Reset Driver"

	depends on HAS_IOMEM

drivers/reset/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ obj-$(CONFIG_RESET_ATH79) += reset-ath79.o 
obj-$(CONFIG_RESET_AXS10X) += reset-axs10x.o

obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o

obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o

obj-$(CONFIG_RESET_BRCMSTB_RESCAL) += reset-brcmstb-rescal.o

obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o

obj-$(CONFIG_RESET_IMX7) += reset-imx7.o

obj-$(CONFIG_RESET_INTEL_GW) += reset-intel-gw.o

drivers/reset/reset-brcmstb-rescal.c

0 → 100644
+107 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (C) 2018-2020 Broadcom */



#include <linux/device.h>

#include <linux/iopoll.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/reset-controller.h>



#define BRCM_RESCAL_START	0x0

#define  BRCM_RESCAL_START_BIT	BIT(0)

#define BRCM_RESCAL_CTRL	0x4

#define BRCM_RESCAL_STATUS	0x8

#define  BRCM_RESCAL_STATUS_BIT	BIT(0)



struct brcm_rescal_reset {

	void __iomem *base;

	struct device *dev;

	struct reset_controller_dev rcdev;

};



static int brcm_rescal_reset_set(struct reset_controller_dev *rcdev,

				 unsigned long id)

{

	struct brcm_rescal_reset *data =

		container_of(rcdev, struct brcm_rescal_reset, rcdev);

	void __iomem *base = data->base;

	u32 reg;

	int ret;



	reg = readl(base + BRCM_RESCAL_START);

	writel(reg | BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);

	reg = readl(base + BRCM_RESCAL_START);

	if (!(reg & BRCM_RESCAL_START_BIT)) {

		dev_err(data->dev, "failed to start SATA/PCIe rescal\n");

		return -EIO;

	}



	ret = readl_poll_timeout(base + BRCM_RESCAL_STATUS, reg,

				 !(reg & BRCM_RESCAL_STATUS_BIT), 100, 1000);

	if (ret) {

		dev_err(data->dev, "time out on SATA/PCIe rescal\n");

		return ret;

	}



	reg = readl(base + BRCM_RESCAL_START);

	writel(reg & ~BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);



	dev_dbg(data->dev, "SATA/PCIe rescal success\n");



	return 0;

}



static int brcm_rescal_reset_xlate(struct reset_controller_dev *rcdev,

				   const struct of_phandle_args *reset_spec)

{

	/* This is needed if #reset-cells == 0. */

	return 0;

}



static const struct reset_control_ops brcm_rescal_reset_ops = {

	.reset = brcm_rescal_reset_set,

};



static int brcm_rescal_reset_probe(struct platform_device *pdev)

{

	struct brcm_rescal_reset *data;

	struct resource *res;



	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	data->base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(data->base))

		return PTR_ERR(data->base);



	data->rcdev.owner = THIS_MODULE;

	data->rcdev.nr_resets = 1;

	data->rcdev.ops = &brcm_rescal_reset_ops;

	data->rcdev.of_node = pdev->dev.of_node;

	data->rcdev.of_xlate = brcm_rescal_reset_xlate;

	data->dev = &pdev->dev;



	return devm_reset_controller_register(&pdev->dev, &data->rcdev);

}



static const struct of_device_id brcm_rescal_reset_of_match[] = {

	{ .compatible = "brcm,bcm7216-pcie-sata-rescal" },

	{ },

};

MODULE_DEVICE_TABLE(of, brcm_rescal_reset_of_match);



static struct platform_driver brcm_rescal_reset_driver = {

	.probe = brcm_rescal_reset_probe,

	.driver = {

		.name	= "brcm-rescal-reset",

		.of_match_table	= brcm_rescal_reset_of_match,

	}

};

module_platform_driver(brcm_rescal_reset_driver);



MODULE_AUTHOR("Broadcom");

MODULE_DESCRIPTION("Broadcom SATA/PCIe rescal reset controller");

MODULE_LICENSE("GPL v2");