Implement SoC bus support for Vybrid

cd /sys/devices/soc0
ls

cat family

cat machine

cat revision

cat soc_id

drivers/soc/fsl/Kconfig new file +7 -0

 
+config SOC_BUS_VF610
+	   tristate "SoC bus device for the Freescale Vybrid platform"
+	   depends on SOC_VF610
+	   select SOC_BUS
+	   help
+	     Include support for the SoC bus on the Freescale Vybrid platform
+		 providing some sysfs information about the module variant.

drivers/soc/fsl/Makefile new file +1 -0

 
+obj-$(CONFIG_SOC_BUS_VF610)		+= soc-vf610.o

drivers/soc/fsl/soc-vf610.c new file +156 -0

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2015 Toradex AG
+ *
+ * Author: Sanchayan Maity <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define DRIVER_NAME "vf610-soc-bus"
+
+#define MSCM_CPxCOUNT_OFFSET   0x0000002C
+#define MSCM_CPxCFG1_OFFSET    0x00000014
+
+struct vf610_soc {
+	struct device *dev;
+	struct soc_device_attribute *soc_dev_attr;
+	struct soc_device *soc_dev;
+};
+
+static int vf610_soc_probe(struct platform_device *pdev)
+{
+	struct vf610_soc *info;
+	struct regmap *ocotp_regmap, *mscm_regmap, *rom_regmap;
+	struct device *dev = &pdev->dev;
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *soc_node;
+	struct of_phandle_args pargs;
+	char soc_type[] = "xx0";
+	u32 cfg0_offset, cfg1_offset, rom_rev_offset;
+	u32 soc_id1, soc_id2, rom_rev;
+	u32 cpxcount, cpxcfg1;
+	u64 soc_id;
+	int ret;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(struct vf610_soc), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = &pdev->dev;
+	platform_set_drvdata(pdev, info);
+
+	mscm_regmap = syscon_node_to_regmap(node);
+	if (IS_ERR(mscm_regmap)) {
+		dev_err(dev, "regmap lookup for mscm failed\n");
+		return PTR_ERR(mscm_regmap);
+	}
+
+	soc_node = of_find_node_by_path("/soc");
+
+	ret = of_parse_phandle_with_fixed_args(soc_node,
+					"ocotp-cfg", 2, 0, &pargs);
+	if (ret) {
+		dev_err(dev, "lookup failed for ocotp-cfg node %d\n", ret);
+		return ret;
+	}
+
+	ocotp_regmap = syscon_node_to_regmap(pargs.np);
+	if (IS_ERR(ocotp_regmap)) {
+		of_node_put(pargs.np);
+		dev_err(dev, "regmap lookup for ocotp failed\n");
+		return PTR_ERR(ocotp_regmap);
+	}
+
+	cfg0_offset = pargs.args[0];
+	cfg1_offset = pargs.args[1];
+	of_node_put(pargs.np);
+
+	ret = of_parse_phandle_with_fixed_args(soc_node,
+					"rom-revision", 1, 0, &pargs);
+	if (ret) {
+		dev_err(dev, "lookup failed for rom-revision node %d\n", ret);
+		return ret;
+	}
+
+	rom_regmap = syscon_node_to_regmap(pargs.np);
+	if (IS_ERR(rom_regmap)) {
+		of_node_put(pargs.np);
+		dev_err(dev, "regmap lookup for ocrom failed\n");
+		return PTR_ERR(rom_regmap);
+	}
+
+	rom_rev_offset = pargs.args[0];
+	of_node_put(pargs.np);
+
+	ret = regmap_read(ocotp_regmap, cfg0_offset, &soc_id1);
+	if (ret)
+		return -ENODEV;
+
+	ret = regmap_read(ocotp_regmap, cfg1_offset, &soc_id2);
+	if (ret)
+		return -ENODEV;
+
+	soc_id = (u64) soc_id1 << 32 | soc_id2;
+	add_device_randomness(&soc_id, sizeof(soc_id));
+
+	ret = regmap_read(mscm_regmap, MSCM_CPxCOUNT_OFFSET, &cpxcount);
+	if (ret)
+		return -ENODEV;
+
+	ret = regmap_read(mscm_regmap, MSCM_CPxCFG1_OFFSET, &cpxcfg1);
+	if (ret)
+		return -ENODEV;
+
+	soc_type[0] = cpxcount ? '6' : '5'; /* Dual Core => VF6x0 */
+	soc_type[1] = cpxcfg1 ? '1' : '0'; /* L2 Cache => VFx10 */
+
+	ret = regmap_read(rom_regmap, rom_rev_offset, &rom_rev);
+	if (ret)
+		return -ENODEV;
+
+	info->soc_dev_attr = devm_kzalloc(&pdev->dev,
+				sizeof(info->soc_dev_attr), GFP_KERNEL);
+	if (!info->soc_dev_attr)
+		return -ENOMEM;
+
+	info->soc_dev_attr->machine = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "Freescale Vybrid");
+	info->soc_dev_attr->soc_id = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "%016llx", soc_id);
+	info->soc_dev_attr->family = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "Freescale Vybrid VF%s",
+				soc_type);
+	info->soc_dev_attr->revision = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "%08x", rom_rev);
+
+	info->soc_dev = soc_device_register(info->soc_dev_attr);
+	if (IS_ERR(info->soc_dev))
+		return -ENODEV;
+
+	return 0;
+}
+
+static int vf610_soc_remove(struct platform_device *pdev)
+{
+	struct vf610_soc *info = platform_get_drvdata(pdev);
+
+	if (info->soc_dev)
+		soc_device_unregister(info->soc_dev);
+
+	return 0;
+}
+
+static const struct of_device_id vf610_soc_bus_match[] = {
+	{ .compatible = "fsl,vf610-mscm-cpucfg", },
+	{ /* sentinel */ }
+};

Add a device tree node for the On-Chip One Time Programmable Controller (OCOTP) and the On-Chip ROM.

Signed-off-by Sanchayan Maity <[email protected]>

---
 arch/arm/boot/dts/vfxxx.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

arch/arm/boot/dts/vfxxx.dtsi +0 -0

index 2f4b04d..ed9b6b8 100644

Hi,

Quoted 18 lines · Sanchayan Maity

Add a device tree node for the On-Chip One Time Programmable Controller (OCOTP) and the On-Chip ROM.

Signed-off-by Sanchayan Maity <[email protected]>

---
 arch/arm/boot/dts/vfxxx.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

arch/arm/boot/dts/vfxxx.dtsi +2 -0

index 2f4b04d..ed9b6b8 100644
@@ -56,6 +56,13 @@
 		compatible = "simple-bus";
 		interrupt-parent = <&mscm_ir>;
 		ranges;
+		ocotp-cfg = <&ocotp 0x410 0x420>;
+		rom-revision = <&ocrom 0x80>;

arch/arm/boot/dts/vfxxx.dtsi line 65

Quoted 5 lines

arch/arm/boot/dts/vfxxx.dtsi +5 -0

+
+		ocrom: ocrom {
+			compatible = "fsl,vf610-ocrom", "syscon";
+			reg = <0x00000000 0x18000>;
+		};

Shouldn't that use the new nvmem framework currently being discussed, instead of defining custom bindings?

Quoted 181 lines · Sanchayan Maity

drivers/soc/fsl/Kconfig new file +7 -0

 
+config SOC_BUS_VF610
+	   tristate "SoC bus device for the Freescale Vybrid platform"
+	   depends on SOC_VF610
+	   select SOC_BUS
+	   help
+	     Include support for the SoC bus on the Freescale Vybrid platform
+		 providing some sysfs information about the module variant.

drivers/soc/fsl/Makefile new file +1 -0

 
+obj-$(CONFIG_SOC_BUS_VF610)		+= soc-vf610.o

drivers/soc/fsl/soc-vf610.c new file +162 -0

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2015 Toradex AG
+ *
+ * Author: Sanchayan Maity <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define DRIVER_NAME "vf610-soc-bus"
+
+#define MSCM_CPxCOUNT_OFFSET   0x0000002C
+#define MSCM_CPxCFG1_OFFSET    0x00000014
+
+struct vf610_soc {
+	struct device *dev;
+	struct soc_device_attribute *soc_dev_attr;
+	struct soc_device *soc_dev;
+};
+
+static int vf610_soc_probe(struct platform_device *pdev)
+{
+	struct vf610_soc *info;
+	struct regmap *ocotp_regmap, *mscm_regmap, *rom_regmap;
+	struct device *dev = &pdev->dev;
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *soc_node;
+	struct of_phandle_args pargs;
+	char soc_type[] = "xx0";
+	u32 cfg0_offset, cfg1_offset, rom_rev_offset;
+	u32 soc_id1, soc_id2, rom_rev;
+	u32 cpxcount, cpxcfg1;
+	u64 soc_id;
+	int ret;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(struct vf610_soc), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->dev = &pdev->dev;
+	platform_set_drvdata(pdev, info);
+
+	mscm_regmap = syscon_node_to_regmap(node);
+	if (IS_ERR(mscm_regmap)) {
+		dev_err(dev, "regmap lookup for mscm failed\n");
+		return PTR_ERR(mscm_regmap);
+	}
+
+	soc_node = of_find_node_by_path("/soc");
+
+	ret = of_parse_phandle_with_fixed_args(soc_node,
+					"ocotp-cfg", 2, 0, &pargs);
+	if (ret) {
+		dev_err(dev, "lookup failed for ocotp-cfg node %d\n", ret);
+		return ret;
+	}
+
+	ocotp_regmap = syscon_node_to_regmap(pargs.np);
+	if (IS_ERR(ocotp_regmap)) {
+		of_node_put(pargs.np);
+		dev_err(dev, "regmap lookup for ocotp failed\n");
+		return PTR_ERR(ocotp_regmap);
+	}
+
+	cfg0_offset = pargs.args[0];
+	cfg1_offset = pargs.args[1];
+	of_node_put(pargs.np);
+
+	ret = of_parse_phandle_with_fixed_args(soc_node,
+					"rom-revision", 1, 0, &pargs);
+	if (ret) {
+		dev_err(dev, "lookup failed for rom-revision node %d\n", ret);
+		return ret;
+	}
+
+	rom_regmap = syscon_node_to_regmap(pargs.np);
+	if (IS_ERR(rom_regmap)) {
+		of_node_put(pargs.np);
+		dev_err(dev, "regmap lookup for ocrom failed\n");
+		return PTR_ERR(rom_regmap);
+	}
+
+	rom_rev_offset = pargs.args[0];
+	of_node_put(pargs.np);
+
+	ret = regmap_read(ocotp_regmap, cfg0_offset, &soc_id1);
+	if (ret)
+		return -ENODEV;
+
+	ret = regmap_read(ocotp_regmap, cfg1_offset, &soc_id2);
+	if (ret)
+		return -ENODEV;
+
+	soc_id = (u64) soc_id1 << 32 | soc_id2;
+	add_device_randomness(&soc_id, sizeof(soc_id));
+
+	ret = regmap_read(mscm_regmap, MSCM_CPxCOUNT_OFFSET, &cpxcount);
+	if (ret)
+		return -ENODEV;
+
+	ret = regmap_read(mscm_regmap, MSCM_CPxCFG1_OFFSET, &cpxcfg1);
+	if (ret)
+		return -ENODEV;
+
+	soc_type[0] = cpxcount ? '6' : '5'; /* Dual Core => VF6x0 */
+	soc_type[1] = cpxcfg1 ? '1' : '0'; /* L2 Cache => VFx10 */
+
+	ret = regmap_read(rom_regmap, rom_rev_offset, &rom_rev);
+	if (ret)
+		return -ENODEV;
+
+	info->soc_dev_attr = devm_kzalloc(&pdev->dev,
+				sizeof(info->soc_dev_attr), GFP_KERNEL);
+	if (!info->soc_dev_attr)
+		return -ENOMEM;
+
+	info->soc_dev_attr->machine = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "Freescale Vybrid");
+	info->soc_dev_attr->soc_id = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "%016llx", soc_id);
+	info->soc_dev_attr->family = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "Freescale Vybrid VF%s",
+				soc_type);
+	info->soc_dev_attr->revision = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "%08x", rom_rev);
+
+	info->soc_dev = soc_device_register(info->soc_dev_attr);
+	if (IS_ERR(info->soc_dev))
+		return -ENODEV;
+
+	return 0;
+}
+
+static int vf610_soc_remove(struct platform_device *pdev)
+{
+	struct vf610_soc *info = platform_get_drvdata(pdev);
+
+	if (info->soc_dev)
+		soc_device_unregister(info->soc_dev);
+
+	return 0;
+}
+
+static const struct of_device_id vf610_soc_bus_match[] = {
+	{ .compatible = "fsl,vf610-mscm-cpucfg", },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver vf610_soc_driver = {
+	.probe          = vf610_soc_probe,
+	.remove         = vf610_soc_remove,
+	.driver         = {
+		.name   = DRIVER_NAME,

drivers/soc/fsl/soc-vf610.c line 166

Quoted 4 lines

drivers/soc/fsl/soc-vf610.c new file +4 -0

+		.of_match_table = vf610_soc_bus_match,
+	},
+};
+module_platform_driver(vf610_soc_driver);

The Kconfig symbol is tristate now, but all module specific code is gone from this file (ie, MODULE_DEVICE_TABLE, MODULE_DESCRIPTION and MODULE_LICENSE). Why's that?

Quoted 18 lines

Quoted 18 lines

Add a device tree node for the On-Chip One Time Programmable Controller (OCOTP) and the On-Chip ROM.

Signed-off-by Sanchayan Maity <[email protected]>

---
 arch/arm/boot/dts/vfxxx.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

arch/arm/boot/dts/vfxxx.dtsi +2 -0

index 2f4b04d..ed9b6b8 100644
@@ -56,6 +56,13 @@
 		compatible = "simple-bus";
 		interrupt-parent = <&mscm_ir>;
 		ranges;
+		ocotp-cfg = <&ocotp 0x410 0x420>;
+		rom-revision = <&ocrom 0x80>;

Quoted 8 lines

arch/arm/boot/dts/vfxxx.dtsi line 65

Quoted 5 lines

arch/arm/boot/dts/vfxxx.dtsi +5 -0

+
+		ocrom: ocrom {
+			compatible = "fsl,vf610-ocrom", "syscon";
+			reg = <0x00000000 0x18000>;
+		};

Shouldn't that use the new nvmem framework currently being discussed, instead of defining custom bindings?

I am aware of those nvmem framework patches by Srinivas, however from what I can see that framework has not been merged yet atleast from the mail chain that I see for v5 of the patchset so I have not properly looked into that. Mark Brown did apply the regmap patches to his tree, but has the rest of the framework been merged or is it expected to be merged?

If it is expected to be merged and if that framework is a fit for what we are trying to do here and it seems so on a quick glance, then I can go with that. However I still did like to hear from Arnd or have some more comments before I go for that approach with the next respin.