[PATCH v2 4/5] soc: Add SoC bus driver for Freescale Vybrid Platform

From: Sanchayan Maity
Date: Mon May 02 2016 - 03:12:25 EST


This adds a SoC driver to be used by Freescale Vybrid SoC's.
Driver utilises syscon and nvmem consumer API's to get the
various register values needed and sysfs exposes the SoC specific
properties.

A sample output from Colibri Vybrid VF61 is below:

root@colibri-vf:~# cd /sys/bus/soc/devices/soc0
root@colibri-vf:/sys/bus/soc/devices/soc0# ls
family machine power revision soc_id subsystem uevent
root@colibri-vf:/sys/bus/soc/devices/soc0# cat family
Freescale Vybrid VF610
root@colibri-vf:/sys/bus/soc/devices/soc0# cat machine
Freescale Vybrid
root@colibri-vf:/sys/bus/soc/devices/soc0# cat revision
00000013
root@colibri-vf:/sys/bus/soc/devices/soc0# cat soc_id
df6472a6130f29d4

Signed-off-by: Sanchayan Maity <maitysanchayan@xxxxxxxxx>
---
drivers/soc/Kconfig | 1 +
drivers/soc/fsl/Kconfig | 10 +++
drivers/soc/fsl/Makefile | 1 +
drivers/soc/fsl/soc-vf610.c | 160 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 172 insertions(+)
create mode 100644 drivers/soc/fsl/Kconfig
create mode 100644 drivers/soc/fsl/soc-vf610.c

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index cb58ef0..4410eb7 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -2,6 +2,7 @@ menu "SOC (System On Chip) specific Drivers"

source "drivers/soc/bcm/Kconfig"
source "drivers/soc/brcmstb/Kconfig"
+source "drivers/soc/fsl/Kconfig"
source "drivers/soc/fsl/qe/Kconfig"
source "drivers/soc/mediatek/Kconfig"
source "drivers/soc/qcom/Kconfig"
diff --git a/drivers/soc/fsl/Kconfig b/drivers/soc/fsl/Kconfig
new file mode 100644
index 0000000..029ea17
--- /dev/null
+++ b/drivers/soc/fsl/Kconfig
@@ -0,0 +1,10 @@
+#
+# Freescale SoC drivers
+
+config SOC_BUS_VF610
+ bool "SoC bus device for the Freescale Vybrid platform"
+ depends on NVMEM && NVMEM_VF610_OCOTP
+ select SOC_BUS
+ help
+ Include support for the SoC bus on the Freescale Vybrid platform
+ providing sysfs information about the module variant.
diff --git a/drivers/soc/fsl/Makefile b/drivers/soc/fsl/Makefile
index 203307f..afaf092 100644
--- a/drivers/soc/fsl/Makefile
+++ b/drivers/soc/fsl/Makefile
@@ -2,5 +2,6 @@
# Makefile for the Linux Kernel SOC fsl specific device drivers
#

+obj-$(CONFIG_SOC_VF610) += soc-vf610.o
obj-$(CONFIG_QUICC_ENGINE) += qe/
obj-$(CONFIG_CPM) += qe/
diff --git a/drivers/soc/fsl/soc-vf610.c b/drivers/soc/fsl/soc-vf610.c
new file mode 100644
index 0000000..99bf641
--- /dev/null
+++ b/drivers/soc/fsl/soc-vf610.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2016 Toradex AG.
+ *
+ * Author: Sanchayan Maity <sanchayan.maity@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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/device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/random.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+struct vf610_soc {
+ struct device *dev;
+ struct soc_device_attribute *soc_dev_attr;
+ struct soc_device *soc_dev;
+ struct nvmem_cell *ocotp_cfg0;
+ struct nvmem_cell *ocotp_cfg1;
+};
+
+static int vf610_soc_probe(struct platform_device *pdev)
+{
+ struct vf610_soc *info;
+ struct device *dev = &pdev->dev;
+ struct device_node *soc_node;
+ char soc_type[] = "xx0";
+ size_t id1_len;
+ size_t id2_len;
+ u32 cpucount;
+ u32 l2size;
+ u32 rom_rev;
+ u8 *socid1;
+ u8 *socid2;
+ int ret;
+
+ info = devm_kzalloc(dev, sizeof(struct vf610_soc), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ info->dev = dev;
+
+ info->ocotp_cfg0 = devm_nvmem_cell_get(dev, "cfg0");
+ if (IS_ERR(info->ocotp_cfg0))
+ return -EPROBE_DEFER;
+
+ info->ocotp_cfg1 = devm_nvmem_cell_get(dev, "cfg1");
+ if (IS_ERR(info->ocotp_cfg1))
+ return -EPROBE_DEFER;
+
+ socid1 = nvmem_cell_read(info->ocotp_cfg0, &id1_len);
+ if (IS_ERR(socid1)) {
+ dev_err(dev, "Could not read nvmem cell %ld\n",
+ PTR_ERR(socid1));
+ return PTR_ERR(socid1);
+ }
+
+ socid2 = nvmem_cell_read(info->ocotp_cfg1, &id2_len);
+ if (IS_ERR(socid2)) {
+ dev_err(dev, "Could not read nvmem cell %ld\n",
+ PTR_ERR(socid2));
+ return PTR_ERR(socid2);
+ }
+ add_device_randomness(socid1, id1_len);
+ add_device_randomness(socid2, id2_len);
+
+ soc_node = of_find_node_by_path("/soc");
+ if (soc_node == NULL)
+ return -ENODEV;
+
+ ret = syscon_regmap_read_from_offset(soc_node,
+ "fsl,rom-revision", &rom_rev);
+ if (ret) {
+ of_node_put(soc_node);
+ return ret;
+ }
+
+ ret = syscon_regmap_read_from_offset(soc_node,
+ "fsl,cpu-count", &cpucount);
+ if (ret) {
+ of_node_put(soc_node);
+ return ret;
+ }
+
+ ret = syscon_regmap_read_from_offset(soc_node,
+ "fsl,l2-size", &l2size);
+ if (ret) {
+ of_node_put(soc_node);
+ return ret;
+ }
+
+ of_node_put(soc_node);
+
+ soc_type[0] = cpucount ? '6' : '5'; /* Dual Core => VF6x0 */
+ soc_type[1] = l2size ? '1' : '0'; /* L2 Cache => VFx10 */
+
+ info->soc_dev_attr = devm_kzalloc(dev,
+ sizeof(info->soc_dev_attr), GFP_KERNEL);
+ if (!info->soc_dev_attr)
+ return -ENOMEM;
+
+ info->soc_dev_attr->machine = devm_kasprintf(dev,
+ GFP_KERNEL, "Freescale Vybrid");
+ info->soc_dev_attr->soc_id = devm_kasprintf(dev,
+ GFP_KERNEL,
+ "%02x%02x%02x%02x%02x%02x%02x%02x",
+ socid1[3], socid1[2], socid1[1],
+ socid1[0], socid2[3], socid2[2],
+ socid2[1], socid2[0]);
+ info->soc_dev_attr->family = devm_kasprintf(&pdev->dev,
+ GFP_KERNEL, "Freescale Vybrid VF%s",
+ soc_type);
+ info->soc_dev_attr->revision = devm_kasprintf(dev,
+ GFP_KERNEL, "%08x", rom_rev);
+
+ platform_set_drvdata(pdev, info);
+
+ 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-soc-bus", },
+ { /* */ }
+};
+
+static struct platform_driver vf610_soc_driver = {
+ .probe = vf610_soc_probe,
+ .remove = vf610_soc_remove,
+ .driver = {
+ .name = "vf610-soc-bus",
+ .of_match_table = vf610_soc_bus_match,
+ },
+};
+builtin_platform_driver(vf610_soc_driver);
--
2.8.2