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author | Jim Quinlan <jim2101024@gmail.com> | 2020-01-03 11:04:29 -0800 |
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committer | Philipp Zabel <p.zabel@pengutronix.de> | 2020-01-06 10:02:03 +0100 |
commit | 4cf176e52397853e4a4dd37e917c5eafb47ba8d1 (patch) | |
tree | 0c20553ef5bc0b5490ef1072b10caee9e7af1f77 /drivers/reset | |
parent | f6e1405f7a1698234e5143a806453d60f893c651 (diff) | |
download | lwn-4cf176e52397853e4a4dd37e917c5eafb47ba8d1.tar.gz lwn-4cf176e52397853e4a4dd37e917c5eafb47ba8d1.zip |
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: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Diffstat (limited to 'drivers/reset')
-rw-r--r-- | drivers/reset/Kconfig | 7 | ||||
-rw-r--r-- | drivers/reset/Makefile | 1 | ||||
-rw-r--r-- | drivers/reset/reset-brcmstb-rescal.c | 107 |
3 files changed, 115 insertions, 0 deletions
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 04f160245b24..9b7025481644 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -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 diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 4ac9370c7b7c..249ed357c997 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -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 diff --git a/drivers/reset/reset-brcmstb-rescal.c b/drivers/reset/reset-brcmstb-rescal.c new file mode 100644 index 000000000000..b6f074d6a65f --- /dev/null +++ b/drivers/reset/reset-brcmstb-rescal.c @@ -0,0 +1,107 @@ +// 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"); |