Hi Krzysztof, On 7/23/19 2:57 PM, Krzysztof Kozlowski wrote: > On Thu, 18 Jul 2019 at 16:31, Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> wrote: >> >> From: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> >> >> Exynos SoCs have Chipid, for identification of product IDs and SoC >> revisions. This patch intends to provide initialization code for all >> these functionalities, at the same time it provides some sysfs entries >> for accessing these information to user-space. >> >> This driver uses existing binding for exynos-chipid. >> >> Changes by Bartlomiej: >> - fixed return values on errors >> - removed bogus kfree_const() >> - added missing Exynos4210 EVT0 id >> - converted code to use EXYNOS_MASK define >> - fixed np use after of_node_put() >> - fixed too early use of dev_info() >> - made driver fail for unknown SoC-s >> - added SPDX tag >> - updated Copyrights >> >> Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> >> [m.szyprowski: for suggestion and code snippet of product_id_to_soc_id] >> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> >> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> >> [s.nawrocki: updated copyright date] >> Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> >> --- >> drivers/soc/samsung/Kconfig | 5 ++ >> drivers/soc/samsung/Makefile | 2 + >> drivers/soc/samsung/exynos-chipid.c | 111 ++++++++++++++++++++++++++++ >> 3 files changed, 118 insertions(+) >> create mode 100644 drivers/soc/samsung/exynos-chipid.c >> >> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig >> index 2186285fda92..2905f5262197 100644 >> --- a/drivers/soc/samsung/Kconfig >> +++ b/drivers/soc/samsung/Kconfig >> @@ -7,6 +7,11 @@ menuconfig SOC_SAMSUNG >> >> if SOC_SAMSUNG >> >> +config EXYNOS_CHIPID >> + bool "Exynos Chipid controller driver" if COMPILE_TEST >> + depends on ARCH_EXYNOS || COMPILE_TEST >> + select SOC_BUS >> + >> config EXYNOS_PMU >> bool "Exynos PMU controller driver" if COMPILE_TEST >> depends on ARCH_EXYNOS || ((ARM || ARM64) && COMPILE_TEST) >> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile >> index 29f294baac6e..3b6a8797416c 100644 >> --- a/drivers/soc/samsung/Makefile >> +++ b/drivers/soc/samsung/Makefile >> @@ -1,4 +1,6 @@ >> # SPDX-License-Identifier: GPL-2.0 >> + >> +obj-$(CONFIG_EXYNOS_CHIPID) += exynos-chipid.o >> obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o >> >> obj-$(CONFIG_EXYNOS_PMU_ARM_DRIVERS) += exynos3250-pmu.o exynos4-pmu.o \ >> diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c >> new file mode 100644 >> index 000000000000..78b123ee60c0 >> --- /dev/null >> +++ b/drivers/soc/samsung/exynos-chipid.c >> @@ -0,0 +1,111 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright (c) 2019 Samsung Electronics Co., Ltd. >> + * http://www.samsung.com/ >> + * >> + * EXYNOS - CHIP ID support >> + * Author: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> >> + * Author: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> >> + */ >> + >> +#include <linux/io.h> >> +#include <linux/of.h> >> +#include <linux/of_address.h> >> +#include <linux/of_platform.h> >> +#include <linux/platform_device.h> > > Any changes here from my previous comments? > > I have also one more new thought later. > >> +#include <linux/slab.h> >> +#include <linux/sys_soc.h> >> + >> +#define EXYNOS_SUBREV_MASK (0xF << 4) >> +#define EXYNOS_MAINREV_MASK (0xF << 0) >> +#define EXYNOS_REV_MASK (EXYNOS_SUBREV_MASK | EXYNOS_MAINREV_MASK) >> +#define EXYNOS_MASK 0xFFFFF000 >> + >> +static const struct exynos_soc_id { >> + const char *name; >> + unsigned int id; >> +} soc_ids[] = { >> + { "EXYNOS3250", 0xE3472000 }, >> + { "EXYNOS4210", 0x43200000 }, /* EVT0 revision */ >> + { "EXYNOS4210", 0x43210000 }, >> + { "EXYNOS4212", 0x43220000 }, >> + { "EXYNOS4412", 0xE4412000 }, >> + { "EXYNOS5250", 0x43520000 }, >> + { "EXYNOS5260", 0xE5260000 }, >> + { "EXYNOS5410", 0xE5410000 }, >> + { "EXYNOS5420", 0xE5420000 }, >> + { "EXYNOS5440", 0xE5440000 }, >> + { "EXYNOS5800", 0xE5422000 }, >> + { "EXYNOS7420", 0xE7420000 }, >> + { "EXYNOS5433", 0xE5433000 }, >> +}; >> + >> +static const char * __init product_id_to_soc_id(unsigned int product_id) >> +{ >> + int i; >> + >> + for (i = 0; i < ARRAY_SIZE(soc_ids); i++) >> + if ((product_id & EXYNOS_MASK) == soc_ids[i].id) >> + return soc_ids[i].name; >> + return NULL; >> +} >> + >> +int __init exynos_chipid_early_init(void) >> +{ >> + struct soc_device_attribute *soc_dev_attr; >> + void __iomem *exynos_chipid_base; >> + struct soc_device *soc_dev; >> + struct device_node *root; >> + struct device_node *np; >> + u32 product_id; >> + u32 revision; >> + >> + /* look up for chipid node */ >> + np = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-chipid"); >> + if (!np) >> + return -ENODEV; >> + >> + exynos_chipid_base = of_iomap(np, 0); >> + of_node_put(np); >> + >> + if (!exynos_chipid_base) { >> + pr_err("Failed to map SoC chipid\n"); >> + return -ENXIO; >> + } >> + >> + product_id = readl_relaxed(exynos_chipid_base); >> + revision = product_id & EXYNOS_REV_MASK; >> + iounmap(exynos_chipid_base); >> + >> + soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL); >> + if (!soc_dev_attr) >> + return -ENOMEM; >> + >> + soc_dev_attr->family = "Samsung Exynos"; >> + >> + root = of_find_node_by_path("/"); >> + of_property_read_string(root, "model", &soc_dev_attr->machine); >> + of_node_put(root); >> + >> + soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%x", revision); >> + soc_dev_attr->soc_id = product_id_to_soc_id(product_id); >> + if (!soc_dev_attr->soc_id) { >> + pr_err("Unknown SoC\n"); > > In case of running old kernel on unknown SoC (new revision of existing > one or older design not longer supported like 4415), the device will > not bind. This was added by Bartlomiej. Why? I imagine that soc driver > could be still matched and just report "Unknown". I am not sure if > this changes anything, though. I was thinking that we shouldn't be pretending that we know how to handle unsupported SoCs, i.e. that we know how to correctly read its product_id and revision. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics > Best regards, > Krzysztof > > >> + return -ENODEV; >> + } >> + >> + /* please note that the actual registration will be deferred */ >> + soc_dev = soc_device_register(soc_dev_attr); >> + if (IS_ERR(soc_dev)) { >> + kfree(soc_dev_attr->revision); >> + kfree(soc_dev_attr); >> + return PTR_ERR(soc_dev); >> + } >> + >> + /* it is too early to use dev_info() here (soc_dev is NULL) */ >> + pr_info("soc soc0: Exynos: CPU[%s] PRO_ID[0x%x] REV[0x%x] Detected\n", >> + soc_dev_attr->soc_id, product_id, revision); >> + >> + return 0; >> +} >> +early_initcall(exynos_chipid_early_init); >> -- >> 2.17.1
