Re: [RFC 02/11] soc: Add Realtek chip info driver for RTD1195 and RTD1295

From: Andreas FÃrber
Date: Thu Jan 02 2020 - 09:39:24 EST

Am 02.01.20 um 15:29 schrieb James Tai:
Add Stanley Chang for review.

Did you forget to CC him?

Note that this series needs updates once we apply my syscon patches.


Add a soc bus driver to print chip model and revision details.

Revisions from downstream drivers/soc/realtek/rtd{119x,129x}/rtk_chip.c.

Signed-off-by: Andreas FÃrber <afaerber@xxxxxxx>
---
Naming: What to call the family vs. soc_id?

drivers/soc/Kconfig | 1 +
drivers/soc/Makefile | 1 +
drivers/soc/realtek/Kconfig | 13 ++++
drivers/soc/realtek/Makefile | 2 +
drivers/soc/realtek/chip.c | 164
+++++++++++++++++++++++++++++++++++++++++++
5 files changed, 181 insertions(+)
create mode 100644 drivers/soc/realtek/Kconfig create mode 100644
drivers/soc/realtek/Makefile create mode 100644 drivers/soc/realtek/chip.c

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig index
833e04a7835c..06ae9d97321c 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -11,6 +11,7 @@ source "drivers/soc/imx/Kconfig"
source "drivers/soc/ixp4xx/Kconfig"
source "drivers/soc/mediatek/Kconfig"
source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/realtek/Kconfig"
source "drivers/soc/renesas/Kconfig"
source "drivers/soc/rockchip/Kconfig"
source "drivers/soc/samsung/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile index
2ec355003524..1d55d838a342 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_SOC_XWAY) += lantiq/
obj-y += mediatek/
obj-y += amlogic/
obj-y += qcom/
+obj-y += realtek/
obj-y += renesas/
obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
obj-$(CONFIG_SOC_SAMSUNG) += samsung/
diff --git a/drivers/soc/realtek/Kconfig b/drivers/soc/realtek/Kconfig new file
mode 100644 index 000000000000..be75c1889c61
--- /dev/null
+++ b/drivers/soc/realtek/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-or-later if ARCH_REALTEK ||
+COMPILE_TEST
+
+config REALTEK_SOC
+ tristate "Realtek chip info"
+ default ARCH_REALTEK
+ select SOC_BUS
+ help
+ Say 'y' here to enable support for SoC info on Realtek RTD1195 and
+ RTD1295 SoC families.
+ If unsure, say 'n'.
+
+endif
diff --git a/drivers/soc/realtek/Makefile b/drivers/soc/realtek/Makefile new
file mode 100644 index 000000000000..49900273905b
--- /dev/null
+++ b/drivers/soc/realtek/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+obj-$(CONFIG_REALTEK_SOC) += chip.o
diff --git a/drivers/soc/realtek/chip.c b/drivers/soc/realtek/chip.c new file
mode 100644 index 000000000000..9d13422e9936
--- /dev/null
+++ b/drivers/soc/realtek/chip.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Realtek System-on-Chip info
+ *
+ * Copyright (c) 2017-2019 Andreas FÃrber */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#define REG_CHIP_ID 0x0
+#define REG_CHIP_REV 0x4
+
+struct rtd_soc_revision {
+ const char *name;
+ u32 chip_rev;
+};
+
+static const struct rtd_soc_revision rtd1195_revisions[] = {
+ { "A", 0x00000000 },
+ { "B", 0x00010000 },
+ { "C", 0x00020000 },
+ { "D", 0x00030000 },
+ { }
+};
+
+static const struct rtd_soc_revision rtd1295_revisions[] = {
+ { "A00", 0x00000000 },
+ { "A01", 0x00010000 },
+ { "B00", 0x00020000 },
+ { "B01", 0x00030000 },
+ { }
+};

I believe the lower 16 bits are reserved, so we should only be comparing the upper 16.

+
+struct rtd_soc {
+ u32 chip_id;
+ const char *family;
+ const char *(*get_name)(struct device *dev, const struct rtd_soc *s);
+ const struct rtd_soc_revision *revisions;
+ const char *codename;
+};
+
+static const char *default_name(struct device *dev, const struct
+rtd_soc *s) {
+ return s->family;
+}
+
+static const struct rtd_soc rtd_soc_families[] = {
+ { 0x00006329, "RTD1195", default_name, rtd1195_revisions, "Phoenix" },
+ { 0x00006421, "RTD1295", default_name, rtd1295_revisions, "Kylin" },
+};

Similarly here I believe the upper 16 bits are reserved, so we should only be comparing the lower 16, which should make it easier to stay within 80 characters per line.

Regards,
Andreas

+
+static const struct rtd_soc *rtd_soc_by_chip_id(u32 chip_id) {
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(rtd_soc_families); i++) {
+ const struct rtd_soc *family = &rtd_soc_families[i];
+
+ if (family->chip_id == chip_id)
+ return family;
+ }
+ return NULL;
+}
+
+static const char *rtd_soc_rev(const struct rtd_soc *family, u32
+chip_rev) {
+ if (family) {
+ const struct rtd_soc_revision *rev = family->revisions;
+
+ while (rev && rev->name) {
+ if (rev->chip_rev == chip_rev)
+ return rev->name;
+ rev++;
+ }
+ }
+ return "unknown";
+}
+
+static int rtd_soc_probe(struct platform_device *pdev) {
+ const struct rtd_soc *s;
+ struct soc_device_attribute *soc_dev_attr;
+ struct soc_device *soc_dev;
+ struct device_node *node;
+ void __iomem *base;
+ u32 chip_id, chip_rev;
+
+ base = of_iomap(pdev->dev.of_node, 0);
+ if (!base)
+ return -ENODEV;
+
+ soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+ if (!soc_dev_attr)
+ return -ENOMEM;
+
+ chip_id = readl_relaxed(base + REG_CHIP_ID);
+ chip_rev = readl_relaxed(base + REG_CHIP_REV);
+
+ node = of_find_node_by_path("/");
+ of_property_read_string(node, "model", &soc_dev_attr->machine);
+ of_node_put(node);
+
+ s = rtd_soc_by_chip_id(chip_id);
+
+ soc_dev_attr->family = kasprintf(GFP_KERNEL, "Realtek %s",
+ (s && s->codename) ? s->codename :
+ ((s && s->family) ? s->family : "Digital Home Center"));
+
+ if (likely(s && s->get_name))
+ soc_dev_attr->soc_id = s->get_name(&pdev->dev, s);
+ else
+ soc_dev_attr->soc_id = "unknown";
+
+ soc_dev_attr->revision = rtd_soc_rev(s, chip_rev);
+
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR(soc_dev)) {
+ kfree(soc_dev_attr->family);
+ kfree(soc_dev_attr);
+ return PTR_ERR(soc_dev);
+ }
+
+ platform_set_drvdata(pdev, soc_dev);
+
+ dev_info(soc_device_to_device(soc_dev),
+ "%s %s (0x%08x) rev %s (0x%08x) detected\n",
+ soc_dev_attr->family, soc_dev_attr->soc_id, chip_id,
+ soc_dev_attr->revision, chip_rev);
+
+ return 0;
+}
+
+static int rtd_soc_remove(struct platform_device *pdev) {
+ struct soc_device *soc_dev = platform_get_drvdata(pdev);
+
+ soc_device_unregister(soc_dev);
+
+ return 0;
+}
+
+static const struct of_device_id rtd_soc_dt_ids[] = {
+ { .compatible = "realtek,rtd1195-chip" },
+ { }
+};
+
+static struct platform_driver rtd_soc_driver = {
+ .probe = rtd_soc_probe,
+ .remove = rtd_soc_remove,
+ .driver = {
+ .name = "rtd1195-soc",
+ .of_match_table = rtd_soc_dt_ids,
+ },
+};
+module_platform_driver(rtd_soc_driver);
+
+MODULE_DESCRIPTION("Realtek SoC identification");
+MODULE_LICENSE("GPL");
--
2.16.4


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