diff mbox

reset: Add i.MX7 SRC reset driver

Message ID 20170206150836.10001-1-andrew.smirnov@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Andrey Smirnov Feb. 6, 2017, 3:08 p.m. UTC
This driver exposes various reset faculties, impelented by System Reset
Controller IP block, as a reset driver. Currently only PCIE related
reset lines are implemented.

Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 .../devicetree/bindings/reset/fsl,imx7-src.txt     |  47 +++++++
 drivers/reset/Kconfig                              |   8 ++
 drivers/reset/Makefile                             |   1 +
 drivers/reset/reset-imx7.c                         | 149 +++++++++++++++++++++
 include/dt-bindings/reset/imx7-reset.h             |  28 ++++
 5 files changed, 233 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
 create mode 100644 drivers/reset/reset-imx7.c
 create mode 100644 include/dt-bindings/reset/imx7-reset.h

Comments

Rob Herring Feb. 10, 2017, 3:43 p.m. UTC | #1
On Mon, Feb 06, 2017 at 07:08:36AM -0800, Andrey Smirnov wrote:
> This driver exposes various reset faculties, impelented by System Reset
> Controller IP block, as a reset driver. Currently only PCIE related
> reset lines are implemented.
> 
> Cc: Lucas Stach <l.stach@pengutronix.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>  .../devicetree/bindings/reset/fsl,imx7-src.txt     |  47 +++++++
>  drivers/reset/Kconfig                              |   8 ++
>  drivers/reset/Makefile                             |   1 +
>  drivers/reset/reset-imx7.c                         | 149 +++++++++++++++++++++
>  include/dt-bindings/reset/imx7-reset.h             |  28 ++++
>  5 files changed, 233 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
>  create mode 100644 drivers/reset/reset-imx7.c
>  create mode 100644 include/dt-bindings/reset/imx7-reset.h
> 
> diff --git a/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt b/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
> new file mode 100644
> index 0000000..19a77f9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
> @@ -0,0 +1,47 @@
> +Freescale i.MX7 System Reset Controller
> +======================================
> +
> +Please also refer to reset.txt in this directory for common reset
> +controller binding usage.
> +
> +Required properties:
> +- compatible: Should be "fsl,imx7-src", "syscon"

Doesn't match the example. This should be specific. I assume there's 
more than one i.MX7?

> +- reg: should be register base and length as documented in the
> +  datasheet
> +- interrupts: Should contain SRC interrupt
> +- #reset-cells: 1, see below
> +
> +example:
> +
> +src: src@30390000 {

reset-controller@...

> +     compatible = "fsl,imx7d-src", "syscon";
> +     reg = <0x30390000 0x10000>;

Really has 64KB of registers or that's just the block spacing. Assuming 
the actual size is smaller, you are eating up valuable lowmem space by 
mapping all 64KB.

> +     interrupts = <GIC_SPI 89 IRQ_TYPE_LEVEL_HIGH>;
> +     #reset-cells = <1>;
> +};
> +
> +
> +Specifying reset lines connected to IP modules
> +==============================================
> +
> +The system reset controller can be used to reset various set of
> +peripherals. Device nodes that need access to reset lines should
> +specify them as a reset phandle in their corresponding node as
> +specified in reset.txt.
> +
> +Example:
> +
> +	pcie: pcie@0x33800000 {

Drop the 0x.

> +
> +		...
> +
> +		resets = <&src IMX7_RESET_PCIEPHY>,
> +			 <&src IMX7_RESET_PCIE_CTRL_APPS>;
> +		reset-names = "pciephy", "apps";
> +
> +		...
> +        };
> +
> +
> +For list of all valid reset indicies see
> +<dt-bindings/reset/imx7-reset.h>
Andrey Smirnov Feb. 13, 2017, 2:54 p.m. UTC | #2
On Fri, Feb 10, 2017 at 7:43 AM, Rob Herring <robh@kernel.org> wrote:
> On Mon, Feb 06, 2017 at 07:08:36AM -0800, Andrey Smirnov wrote:
>> This driver exposes various reset faculties, impelented by System Reset
>> Controller IP block, as a reset driver. Currently only PCIE related
>> reset lines are implemented.
>>
>> Cc: Lucas Stach <l.stach@pengutronix.de>
>> Cc: Rob Herring <robh+dt@kernel.org>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Fabio Estevam <fabio.estevam@nxp.com>
>> Cc: devicetree@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: linux-arm-kernel@lists.infradead.org
>> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
>> ---
>>  .../devicetree/bindings/reset/fsl,imx7-src.txt     |  47 +++++++
>>  drivers/reset/Kconfig                              |   8 ++
>>  drivers/reset/Makefile                             |   1 +
>>  drivers/reset/reset-imx7.c                         | 149 +++++++++++++++++++++
>>  include/dt-bindings/reset/imx7-reset.h             |  28 ++++
>>  5 files changed, 233 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
>>  create mode 100644 drivers/reset/reset-imx7.c
>>  create mode 100644 include/dt-bindings/reset/imx7-reset.h
>>
>> diff --git a/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt b/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
>> new file mode 100644
>> index 0000000..19a77f9
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
>> @@ -0,0 +1,47 @@
>> +Freescale i.MX7 System Reset Controller
>> +======================================
>> +
>> +Please also refer to reset.txt in this directory for common reset
>> +controller binding usage.
>> +
>> +Required properties:
>> +- compatible: Should be "fsl,imx7-src", "syscon"
>
> Doesn't match the example. This should be specific. I assume there's
> more than one i.MX7?
>
>> +- reg: should be register base and length as documented in the
>> +  datasheet
>> +- interrupts: Should contain SRC interrupt
>> +- #reset-cells: 1, see below
>> +
>> +example:
>> +
>> +src: src@30390000 {
>
> reset-controller@...

OK, will update in v2.

>
>> +     compatible = "fsl,imx7d-src", "syscon";
>> +     reg = <0x30390000 0x10000>;
>
> Really has 64KB of registers or that's just the block spacing. Assuming
> the actual size is smaller, you are eating up valuable lowmem space by
> mapping all 64KB.
>

There are definitely registers within first 8K of that window, and I
have no idea if there are any more undocumented registers going even
further, but IMHO you are very likely to be correct in your assumption
that this is mostly block spacing. I borrowed already existing "src"
node definition from i.MX7 device tree code and that is how it was
defined there. I'll shrink the example to be only 8K.

>> +     interrupts = <GIC_SPI 89 IRQ_TYPE_LEVEL_HIGH>;
>> +     #reset-cells = <1>;
>> +};
>> +
>> +
>> +Specifying reset lines connected to IP modules
>> +==============================================
>> +
>> +The system reset controller can be used to reset various set of
>> +peripherals. Device nodes that need access to reset lines should
>> +specify them as a reset phandle in their corresponding node as
>> +specified in reset.txt.
>> +
>> +Example:
>> +
>> +     pcie: pcie@0x33800000 {
>
> Drop the 0x.

OK, will do in v2.

Thanks,
Andrey Smirnov
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt b/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
new file mode 100644
index 0000000..19a77f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/fsl,imx7-src.txt
@@ -0,0 +1,47 @@ 
+Freescale i.MX7 System Reset Controller
+======================================
+
+Please also refer to reset.txt in this directory for common reset
+controller binding usage.
+
+Required properties:
+- compatible: Should be "fsl,imx7-src", "syscon"
+- reg: should be register base and length as documented in the
+  datasheet
+- interrupts: Should contain SRC interrupt
+- #reset-cells: 1, see below
+
+example:
+
+src: src@30390000 {
+     compatible = "fsl,imx7d-src", "syscon";
+     reg = <0x30390000 0x10000>;
+     interrupts = <GIC_SPI 89 IRQ_TYPE_LEVEL_HIGH>;
+     #reset-cells = <1>;
+};
+
+
+Specifying reset lines connected to IP modules
+==============================================
+
+The system reset controller can be used to reset various set of
+peripherals. Device nodes that need access to reset lines should
+specify them as a reset phandle in their corresponding node as
+specified in reset.txt.
+
+Example:
+
+	pcie: pcie@0x33800000 {
+
+		...
+
+		resets = <&src IMX7_RESET_PCIEPHY>,
+			 <&src IMX7_RESET_PCIE_CTRL_APPS>;
+		reset-names = "pciephy", "apps";
+
+		...
+        };
+
+
+For list of all valid reset indicies see
+<dt-bindings/reset/imx7-reset.h>
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 172dc96..664a88b 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -92,6 +92,14 @@  config RESET_ZYNQ
 	help
 	  This enables the reset controller driver for Xilinx Zynq SoCs.
 
+config RESET_IMX7
+	bool "i.MX7 Reset Driver"
+	depends on SOC_IMX7D || COMPILE_TEST
+	select MFD_SYSCON
+	default SOC_IMX7D
+	help
+	  This enables the reset controller driver for i.MX7 SoCs.
+
 source "drivers/reset/sti/Kconfig"
 source "drivers/reset/hisilicon/Kconfig"
 source "drivers/reset/tegra/Kconfig"
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 13b346e..417c9d0 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -14,3 +14,4 @@  obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_TI_SYSCON_RESET) += reset-ti-syscon.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_RESET_ZYNQ) += reset-zynq.o
+obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
diff --git a/drivers/reset/reset-imx7.c b/drivers/reset/reset-imx7.c
new file mode 100644
index 0000000..6d90e57
--- /dev/null
+++ b/drivers/reset/reset-imx7.c
@@ -0,0 +1,149 @@ 
+/*
+ * Copyright (c) 2017, Impinj, Inc.
+ *
+ * i.MX7 System Reset Controller (SRC) driver
+ *
+ * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+#include <dt-bindings/reset/imx7-reset.h>
+
+struct imx7_src {
+	struct reset_controller_dev rcdev;
+	struct device *dev;
+	struct regmap *regmap;
+};
+
+enum imx7_src_registers {
+	SRC_PCIEPHY_RCR = 0x002c,
+	SRC_PCIEPHY_RCR_PCIEPHY_G_RST     = BIT(1),
+	SRC_PCIEPHY_RCR_PCIEPHY_BTN       = BIT(2),
+	SRC_PCIEPHY_RCR_PCIE_CTRL_APPS_EN = BIT(6),
+};
+
+static struct imx7_src *to_imx7_src(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct imx7_src, rcdev);
+}
+
+static int imx7_reset_assert(struct reset_controller_dev *rcdev,
+			     unsigned long id)
+{
+	struct imx7_src *imx7src = to_imx7_src(rcdev);
+
+	switch (id) {
+	case IMX7_RESET_PCIE_CTRL_APPS:
+		regmap_update_bits(imx7src->regmap,
+				   SRC_PCIEPHY_RCR,
+				   SRC_PCIEPHY_RCR_PCIE_CTRL_APPS_EN, 0);
+		return 0;
+
+	case IMX7_RESET_PCIEPHY:
+		regmap_update_bits(imx7src->regmap,
+				   SRC_PCIEPHY_RCR,
+				   SRC_PCIEPHY_RCR_PCIEPHY_G_RST,
+				   SRC_PCIEPHY_RCR_PCIEPHY_G_RST);
+		regmap_update_bits(imx7src->regmap,
+				   SRC_PCIEPHY_RCR,
+				   SRC_PCIEPHY_RCR_PCIEPHY_BTN,
+				   SRC_PCIEPHY_RCR_PCIEPHY_BTN);
+		return 0;
+	default:
+		dev_err(imx7src->dev, "Unknown reset ID %lu\n", id);
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static int imx7_reset_deassert(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	struct imx7_src *imx7src = to_imx7_src(rcdev);
+
+	switch (id) {
+	case IMX7_RESET_PCIE_CTRL_APPS:
+		regmap_update_bits(imx7src->regmap,
+				   SRC_PCIEPHY_RCR,
+				   SRC_PCIEPHY_RCR_PCIE_CTRL_APPS_EN,
+				   SRC_PCIEPHY_RCR_PCIE_CTRL_APPS_EN);
+		return 0;
+
+	case IMX7_RESET_PCIEPHY:
+		/* wait for more than 10us to release phy g_rst and btnrst */
+		udelay(10);
+		regmap_update_bits(imx7src->regmap,
+				   SRC_PCIEPHY_RCR,
+				   SRC_PCIEPHY_RCR_PCIEPHY_G_RST, 0);
+		regmap_update_bits(imx7src->regmap,
+				   SRC_PCIEPHY_RCR,
+				   SRC_PCIEPHY_RCR_PCIEPHY_BTN, 0);
+		return 0;
+	default:
+		dev_err(imx7src->dev, "Unknown reset ID %lu\n", id);
+		break;
+	};
+
+	return -EINVAL;
+}
+
+static const struct reset_control_ops imx7_reset_ops = {
+	.assert		= imx7_reset_assert,
+	.deassert	= imx7_reset_deassert,
+};
+
+static int imx7_reset_probe(struct platform_device *pdev)
+{
+	struct imx7_src *imx7src;
+	struct device *dev = &pdev->dev;
+
+	imx7src = devm_kzalloc(dev, sizeof(*imx7src), GFP_KERNEL);
+	if (!imx7src)
+		return -ENOMEM;
+
+	imx7src->dev = dev;
+	imx7src->regmap = syscon_node_to_regmap(dev->of_node);
+	if (IS_ERR(imx7src->regmap)) {
+		dev_err(dev, "Unable to get imx7-src regmap");
+		return PTR_ERR(imx7src->regmap);
+	}
+
+	imx7src->rcdev.owner     = THIS_MODULE;
+	imx7src->rcdev.nr_resets = IMX7_RESET_NUM;
+	imx7src->rcdev.ops       = &imx7_reset_ops;
+	imx7src->rcdev.of_node   = dev->of_node;
+
+	return devm_reset_controller_register(dev, &imx7src->rcdev);
+}
+
+static const struct of_device_id imx7_reset_dt_ids[] = {
+	{ .compatible = "fsl,imx7d-src", },
+	{ /* sentinel */ },
+};
+
+static struct platform_driver imx7_reset_driver = {
+	.probe	= imx7_reset_probe,
+	.driver = {
+		.name		= KBUILD_MODNAME,
+		.of_match_table	= imx7_reset_dt_ids,
+	},
+};
+builtin_platform_driver(imx7_reset_driver);
diff --git a/include/dt-bindings/reset/imx7-reset.h b/include/dt-bindings/reset/imx7-reset.h
new file mode 100644
index 0000000..e20f2db
--- /dev/null
+++ b/include/dt-bindings/reset/imx7-reset.h
@@ -0,0 +1,28 @@ 
+/*
+ * Copyright (C) 2017 Impinj, Inc.
+ *
+ * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef DT_BINDING_RESET_IMX7_H
+#define DT_BINDING_RESET_IMX7_H
+
+#define IMX7_RESET_PCIE_CTRL_APPS	0
+#define IMX7_RESET_PCIEPHY		1
+
+#define IMX7_RESET_NUM			2
+
+#endif
+