diff mbox series

[v6,4/4] soc: imx8m: change to use platform driver

Message ID 20201124015949.29262-4-alice.guo@nxp.com
State Accepted
Commit 7d981405d0fd3cfc0de052e4791f516235d8b858
Headers show
Series [v6,1/4] dt-bindings: soc: imx8m: add DT Binding doc for soc unique ID | expand

Commit Message

Alice Guo Nov. 24, 2020, 1:59 a.m. UTC 
Directly reading ocotp register depends on that bootloader enables ocotp
clk, which is not always effective, so change to use nvmem API. Using
nvmem API requires to support driver defer probe and thus change
soc-imx8m.c to use platform driver.

The other reason is that directly reading ocotp register causes kexec
kernel hang because the 1st kernel running will disable unused clks
after kernel boots up, and then ocotp clk will be disabled even if
bootloader enables it. When kexec kernel, ocotp clk needs to be enabled
before reading ocotp registers, and nvmem API with platform driver
supported can accomplish this.

Signed-off-by: Alice Guo <alice.guo@nxp.com>
---

v2: remove the subject prefix "LF-2571-4"
v3: Keep the original way which uses device_initcall to read soc unique
    ID, and add the other way which uses module_platform_driver and
    nvmem API, so that it will not break the old version DTBs.
v4: delete "__maybe_unused"
    delete MODULE_DEVICE_TABLE(of, imx8m_soc_match);
    rename match table, "fsl,imx8mm/n/q/p" is actually a machine
compabile and "fsl,imx8mm/n/q/p-soc" is a compabile of soc@0
    delete "flag" and change to determine whether the pointer is NULL
    ues of_find_matching_node_and_match()
    delete of_match_ptr()
v5: add cleanup part "of_node_put"
    add note to explain that why device_initcall still exists
v6: none

 drivers/soc/imx/soc-imx8m.c | 87 ++++++++++++++++++++++++++++++++-----
 1 file changed, 75 insertions(+), 12 deletions(-)

--
2.17.1

Comments

kernel test robot Dec. 2, 2020, 1:27 a.m. UTC | #1 
Hi Alice,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on v5.10-rc6 next-20201201]
[cannot apply to shawnguo/for-next krzk/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Alice-Guo/dt-bindings-soc-imx8m-add-DT-Binding-doc-for-soc-unique-ID/20201124-100402
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: mips-randconfig-r026-20201201 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 2671fccf0381769276ca8246ec0499adcb9b0355)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        # https://github.com/0day-ci/linux/commit/410e3191d62767ba3d347a48d38ad3bd00bee387
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Alice-Guo/dt-bindings-soc-imx8m-add-DT-Binding-doc-for-soc-unique-ID/20201124-100402
        git checkout 410e3191d62767ba3d347a48d38ad3bd00bee387
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/soc/imx/soc-imx8m.c:174:34: warning: unused variable 'imx8_machine_match' [-Wunused-const-variable]

   static const struct of_device_id imx8_machine_match[] = {
                                    ^
   1 warning generated.

vim +/imx8_machine_match +174 drivers/soc/imx/soc-imx8m.c

   173	
 > 174	static const struct of_device_id imx8_machine_match[] = {

   175		{ .compatible = "fsl,imx8mq", .data = &imx8mq_soc_data, },
   176		{ .compatible = "fsl,imx8mm", .data = &imx8mm_soc_data, },
   177		{ .compatible = "fsl,imx8mn", .data = &imx8mn_soc_data, },
   178		{ .compatible = "fsl,imx8mp", .data = &imx8mp_soc_data, },
   179		{ }
   180	};
   181	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
index cc57a384d74d..250530177920 100644
--- a/drivers/soc/imx/soc-imx8m.c
+++ b/drivers/soc/imx/soc-imx8m.c
@@ -5,6 +5,8 @@ 

 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
 #include <linux/of_address.h>
 #include <linux/slab.h>
 #include <linux/sys_soc.h>
@@ -29,7 +31,7 @@ 

 struct imx8_soc_data {
 	char *name;
-	u32 (*soc_revision)(void);
+	u32 (*soc_revision)(struct device *dev);
 };

 static u64 soc_uid;
@@ -50,7 +52,7 @@  static u32 imx8mq_soc_revision_from_atf(void)
 static inline u32 imx8mq_soc_revision_from_atf(void) { return 0; };
 #endif

-static u32 __init imx8mq_soc_revision(void)
+static u32 __init imx8mq_soc_revision(struct device *dev)
 {
 	struct device_node *np;
 	void __iomem *ocotp_base;
@@ -75,9 +77,20 @@  static u32 __init imx8mq_soc_revision(void)
 			rev = REV_B1;
 	}

-	soc_uid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH);
-	soc_uid <<= 32;
-	soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW);
+	if (dev) {
+		int ret = 0;
+
+		ret = nvmem_cell_read_u64(dev, "soc_unique_id", &soc_uid);
+		if (ret) {
+			iounmap(ocotp_base);
+			of_node_put(np);
+			return ret;
+		}
+	} else {
+		soc_uid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH);
+		soc_uid <<= 32;
+		soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW);
+	}

 	iounmap(ocotp_base);
 	of_node_put(np);
@@ -107,7 +120,7 @@  static void __init imx8mm_soc_uid(void)
 	of_node_put(np);
 }

-static u32 __init imx8mm_soc_revision(void)
+static u32 __init imx8mm_soc_revision(struct device *dev)
 {
 	struct device_node *np;
 	void __iomem *anatop_base;
@@ -125,7 +138,15 @@  static u32 __init imx8mm_soc_revision(void)
 	iounmap(anatop_base);
 	of_node_put(np);

-	imx8mm_soc_uid();
+	if (dev) {
+		int ret = 0;
+
+		ret = nvmem_cell_read_u64(dev, "soc_unique_id", &soc_uid);
+		if (ret)
+			return ret;
+	} else {
+		imx8mm_soc_uid();
+	}

 	return rev;
 }
@@ -150,7 +171,7 @@  static const struct imx8_soc_data imx8mp_soc_data = {
 	.soc_revision = imx8mm_soc_revision,
 };

-static __maybe_unused const struct of_device_id imx8_soc_match[] = {
+static const struct of_device_id imx8_machine_match[] = {
 	{ .compatible = "fsl,imx8mq", .data = &imx8mq_soc_data, },
 	{ .compatible = "fsl,imx8mm", .data = &imx8mm_soc_data, },
 	{ .compatible = "fsl,imx8mn", .data = &imx8mn_soc_data, },
@@ -158,12 +179,20 @@  static __maybe_unused const struct of_device_id imx8_soc_match[] = {
 	{ }
 };

+static const struct of_device_id imx8_soc_match[] = {
+	{ .compatible = "fsl,imx8mq-soc", .data = &imx8mq_soc_data, },
+	{ .compatible = "fsl,imx8mm-soc", .data = &imx8mm_soc_data, },
+	{ .compatible = "fsl,imx8mn-soc", .data = &imx8mn_soc_data, },
+	{ .compatible = "fsl,imx8mp-soc", .data = &imx8mp_soc_data, },
+	{ }
+};
+
 #define imx8_revision(soc_rev) \
 	soc_rev ? \
 	kasprintf(GFP_KERNEL, "%d.%d", (soc_rev >> 4) & 0xf,  soc_rev & 0xf) : \
 	"unknown"

-static int __init imx8_soc_init(void)
+static int imx8_soc_info(struct platform_device *pdev)
 {
 	struct soc_device_attribute *soc_dev_attr;
 	struct soc_device *soc_dev;
@@ -182,7 +211,10 @@  static int __init imx8_soc_init(void)
 	if (ret)
 		goto free_soc;

-	id = of_match_node(imx8_soc_match, of_root);
+	if (pdev)
+		id = of_match_node(imx8_soc_match, pdev->dev.of_node);
+	else
+		id = of_match_node(imx8_machine_match, of_root);
 	if (!id) {
 		ret = -ENODEV;
 		goto free_soc;
@@ -191,8 +223,16 @@  static int __init imx8_soc_init(void)
 	data = id->data;
 	if (data) {
 		soc_dev_attr->soc_id = data->name;
-		if (data->soc_revision)
-			soc_rev = data->soc_revision();
+		if (data->soc_revision) {
+			if (pdev) {
+				soc_rev = data->soc_revision(&pdev->dev);
+				ret = soc_rev;
+				if (ret < 0)
+					goto free_soc;
+			} else {
+				soc_rev = data->soc_revision(NULL);
+			}
+		}
 	}

 	soc_dev_attr->revision = imx8_revision(soc_rev);
@@ -230,4 +270,27 @@  static int __init imx8_soc_init(void)
 	kfree(soc_dev_attr);
 	return ret;
 }
+
+/* Retain device_initcall is for backward compatibility with DTS. */
+static int __init imx8_soc_init(void)
+{
+	int ret = 0;
+
+	if (of_find_matching_node_and_match(NULL, imx8_soc_match, NULL))
+		return 0;
+
+	ret = imx8_soc_info(NULL);
+	return ret;
+}
 device_initcall(imx8_soc_init);
+
+static struct platform_driver imx8_soc_info_driver = {
+	.probe = imx8_soc_info,
+	.driver = {
+		.name = "imx8_soc_info",
+		.of_match_table = imx8_soc_match,
+	},
+};
+
+module_platform_driver(imx8_soc_info_driver);
+MODULE_LICENSE("GPL v2");