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[1/4] base: soc: introduce soc_device_match() interface

Message ID 4811326.1KLIei2jcl@wuerfel (mailing list archive)
State Not Applicable
Headers show

Commit Message

Arnd Bergmann May 30, 2016, 2:57 p.m. UTC 
On Monday, May 30, 2016 3:14:38 PM CEST Arnd Bergmann wrote:
> We keep running into cases where device drivers want to know the exact
> version of the SoC a they are currently running on. In the past, this
> has usually been done through a vendor specific API that can be called
> by a driver, or by directly accessing some kind of version register
> that is not part of the device itself but that belongs to a global
> register area of the chip.
> 
> Common reasons for doing this include:
> 
> - A machine is not using devicetree or similar for passing data
>   about on-chip devices, but just announces their presence using
>   boot-time platform devices, and the machine code itself does
>   not care about the revision.
> 
> - There is existing firmware or boot loaders with existing DT
>   binaries with generic compatible strings that do not identify
>   the particular revision of each device, but the driver knows
>   which SoC revisions include which part
> 
> - A prerelease version of a chip has some quirks and we are
>   using the same version of the bootloader and the DT blob
>   on both the prerelease and the final version. An update of
>   the DT binding seems inappropriate because that would involve
>   maintaining multiple copies of the dts and/or bootloader.
> 
> This introduces the soc_device_match() interface that is meant
> to work like of_match_node() but instead of identifying the
> version of a device, it identifies the SoC itself using a
> vendor-agnostic interface.
> 
> Unlike soc_device_match(), we do not do an exact string compare
> but instead use glob_match() to allow wildcards in strings.

I'm sorry the series introduced build failures (I had done some changes
after testing), here is a quick fixup. I'll resend the whole thing
after someone has looked at it as none of the changes below should
have any influence on the review.

	Arnd
diff mbox

Patch

diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index e9623c6674a5..c38573249777 100644
--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -173,7 +173,7 @@  module_exit(soc_bus_unregister);
 static int soc_device_match_one(struct device *dev, void *arg)
 {
 	struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
-	struct soc_device_attribute *match = arg;
+	const struct soc_device_attribute *match = arg;
 
 	if (match->machine && !glob_match(match->machine, soc_dev->attr->machine))
 		return 0;
@@ -208,7 +208,7 @@  static int soc_device_match_one(struct device *dev, void *arg)
  * soc_device_attribute to pass a structure or function pointer for
  * each entry.
  */
-struct soc_device_attribute *soc_device_match(struct soc_device_attribute *matches)
+const struct soc_device_attribute *soc_device_match(const struct soc_device_attribute *matches)
 {
 	struct device *dev;
 	int ret;
@@ -219,7 +219,7 @@  struct soc_device_attribute *soc_device_match(struct soc_device_attribute *match
 			return NULL;
 
 		dev = NULL;
-		ret = bus_for_each_dev(&soc_bus_type, dev, matches,
+		ret = bus_for_each_dev(&soc_bus_type, dev, (void *)matches,
 					 soc_device_match_one);
 	}
 
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 1d4814fe4cb2..a7b8b05a13e8 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -19,6 +19,8 @@ 
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/mmc/host.h>
+#include <linux/sys_soc.h>
+
 #include "sdhci-pltfm.h"
 #include "sdhci-esdhc.h"
 
@@ -75,7 +77,6 @@  static u16 esdhc_readw_fixup(struct sdhci_host *host,
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
-	u16 ret;
 	int shift = (spec_reg & 0x2) * 8;
 
 	if (spec_reg == SDHCI_HOST_VERSION)
@@ -565,7 +566,7 @@  static const struct sdhci_pltfm_data sdhci_esdhc_le_pdata = {
 };
 
 #define T4240_HOST_VER ((VENDOR_V_23 << SDHCI_VENDOR_VER_SHIFT) | SDHCI_SPEC_200)
-static const struct soc_device_attribute esdhc_t4240_quirk = {
+static const struct soc_device_attribute esdhc_t4240_quirk[] = {
 	/* T4240 revision < 0x20 uses vendor version 23, SDHCI version 200 */
 	{ .soc_id = "T4*(0x824000)", .revision = "0x[01]?",
 	  .data = (void *)(uintptr_t)(T4240_HOST_VER) },
@@ -576,6 +577,7 @@  static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host;
 	struct sdhci_esdhc *esdhc;
+	u32 host_ver;
 
 	pltfm_host = sdhci_priv(host);
 	esdhc = sdhci_pltfm_priv(pltfm_host);
@@ -583,9 +585,9 @@  static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
 	host_ver = sdhci_readw(host, SDHCI_HOST_VERSION);
 
 	if (of_device_is_compatible(pdev->dev.of_node, "fsl,t4240-esdhc")) {
-		struct soc_device_attribute *match;
+		const struct soc_device_attribute *match;
 
-		match = soc_device_match(&esdhc_t4240_quirk);
+		match = soc_device_match(esdhc_t4240_quirk);
 		if (match)
 			host_ver = (uintptr_t)match->data;
 	}
diff --git a/drivers/soc/fsl/guts.c b/drivers/soc/fsl/guts.c
index 2f30698f5bcf..476969644bed 100644
--- a/drivers/soc/fsl/guts.c
+++ b/drivers/soc/fsl/guts.c
@@ -34,14 +34,6 @@  static u32 fsl_guts_get_svr(struct guts *guts)
 		return ioread32be(guts->regs + GUTS_SVR);
 }
 
-static u32 fsl_guts_get_pvr(struct guts *guts)
-{
-	if (guts->little_endian)
-		return ioread32(guts->regs + GUTS_PVR);
-	else
-		return ioread32be(guts->regs + GUTS_PVR);
-}
-
 /*
  * Table for matching compatible strings, for device tree
  * guts node, for Freescale QorIQ SOCs.
@@ -76,13 +68,15 @@  static const struct of_device_id fsl_guts_of_match[] = {
 
 static void fsl_guts_init(struct device *dev, struct guts *guts)
 {
-	const struct of_device_id *id;
 	u32 svr = fsl_guts_get_svr(guts);
+	const struct of_device_id *id;
+	const char *socname;
 
 	guts->soc.family = "NXP QorIQ";
 	id = of_match_node(fsl_guts_of_match, dev->of_node);
-	guts->soc.soc_id = devm_kasprintf(dev, "%s (ver 0x%06x)" id->data,
-					  svr >> 8;
+	socname = id->data;
+	guts->soc.soc_id = devm_kasprintf(dev, GFP_KERNEL, "%s (ver 0x%06x)",
+					  socname, svr >> 8);
 	guts->soc.revision = devm_kasprintf(dev, GFP_KERNEL, "0x%02x",
 					    svr & 0xff);
 }
diff --git a/include/linux/sys_soc.h b/include/linux/sys_soc.h
index 02c48c76052b..3dfc8714a88c 100644
--- a/include/linux/sys_soc.h
+++ b/include/linux/sys_soc.h
@@ -36,6 +36,6 @@  void soc_device_unregister(struct soc_device *soc_dev);
  */
 struct device *soc_device_to_device(struct soc_device *soc);
 
-struct soc_device_attribute *soc_device_match(struct soc_device_attribute *matches);
+const struct soc_device_attribute *soc_device_match(const struct soc_device_attribute *matches);
 
 #endif /* __SOC_BUS_H */