Re: [PATCH v2 2/2] reset: Add Broadcom STB RESCAL reset controller
From: Philipp Zabel <p.zabel@pengutronix.de>
Date: 2020-01-03 09:27:30
Also in:
linux-devicetree, lkml
Hi Florian, just a few small nitpicks: On Thu, 2020-01-02 at 15:14 -0800, Florian Fainelli wrote:
quoted hunk ↗ jump to hunk
From: Jim Quinlan <jim2101024@gmail.com> 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 <redacted> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> --- 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.cdiff --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_IOMEMdiff --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.odiff --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;
You could replace the tab before *base with a space for consistency.
+ 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;Just return ret here, readl_poll_timeout() already returns -ETIMEDOUT.
+ } + + reg = readl(base + BRCM_RESCAL_START); + writel(reg & ~BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START); + (void)readl(base + BRCM_RESCAL_START);
Is this final read actually necessary (if so, why)?
+
+ 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);This can be dropped. regards Philipp _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel