From: Jim Quinlan <jim2101024@xxxxxxxxx>
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 <im2101024@xxxxxxxxx>
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
drivers/reset/Kconfig | 7 ++
drivers/reset/Makefile | 1 +
drivers/reset/reset-brcmstb-rescal.c | 110 +++++++++++++++++++++++++++
3 files changed, 118 insertions(+)
create mode 100644 drivers/reset/reset-brcmstb-rescal.c
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 12f5c897788d..b7cc0a2049d9 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 00767c03f5f2..1e4291185c52 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_LANTIQ) += reset-lantiq.o
diff --git a/drivers/reset/reset-brcmstb-rescal.c b/drivers/reset/reset-brcmstb-rescal.c
new file mode 100644
index 000000000000..e1c038e62855
--- /dev/null
+++ b/drivers/reset/reset-brcmstb-rescal.c
@@ -0,0 +1,110 @@
+// 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 -ETIMEDOUT;
+ }
+
+ reg = readl(base + BRCM_RESCAL_START);
+ writel(reg & ~BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START);
+ (void)readl(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);
+
+ platform_set_drvdata(pdev, data);
+
+ 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");
--
2.17.1
