Several ocelot-related modules are designed for MMIO / regmaps. As such,
they often use a combination of devm_platform_get_and_ioremap_resource()
and devm_regmap_init_mmio().
Operating in an MFD might be different, in that it could be memory mapped,
or it could be SPI, I2C... In these cases a fallback to use IORESOURCE_REG
instead of IORESOURCE_MEM becomes necessary.
When this happens, there's redundant logic that needs to be implemented in
every driver. In order to avoid this redundancy, utilize a single function
that, if the MFD scenario is enabled, will perform this fallback logic.
Signed-off-by: Colin Foster <[email protected]>
Reviewed-by: Vladimir Oltean <[email protected]>
---
v15
* Add missed errno.h and ioport.h includes
* Add () to function references in both the commit log and comments
v14
* Add header guard
* Change regs type from u32* to void*
* Add Reviewed-by tag
---
MAINTAINERS | 5 +++
include/linux/mfd/ocelot.h | 62 ++++++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
create mode 100644 include/linux/mfd/ocelot.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 28108e4fdb8f..f781caceeb38 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14467,6 +14467,11 @@ F: net/dsa/tag_ocelot.c
F: net/dsa/tag_ocelot_8021q.c
F: tools/testing/selftests/drivers/net/ocelot/*
+OCELOT EXTERNAL SWITCH CONTROL
+M: Colin Foster <[email protected]>
+S: Supported
+F: include/linux/mfd/ocelot.h
+
OCXL (Open Coherent Accelerator Processor Interface OpenCAPI) DRIVER
M: Frederic Barrat <[email protected]>
M: Andrew Donnellan <[email protected]>
diff --git a/include/linux/mfd/ocelot.h b/include/linux/mfd/ocelot.h
new file mode 100644
index 000000000000..dd72073d2d4f
--- /dev/null
+++ b/include/linux/mfd/ocelot.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/* Copyright 2022 Innovative Advantage Inc. */
+
+#ifndef _LINUX_MFD_OCELOT_H
+#define _LINUX_MFD_OCELOT_H
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+struct resource;
+
+static inline struct regmap *
+ocelot_regmap_from_resource_optional(struct platform_device *pdev,
+ unsigned int index,
+ const struct regmap_config *config)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ void __iomem *regs;
+
+ /*
+ * Don't use _get_and_ioremap_resource() here, since that will invoke
+ * prints of "invalid resource" which will simply add confusion.
+ */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, index);
+ if (res) {
+ regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(regs))
+ return ERR_CAST(regs);
+ return devm_regmap_init_mmio(dev, regs, config);
+ }
+
+ /*
+ * Fall back to using REG and getting the resource from the parent
+ * device, which is possible in an MFD configuration
+ */
+ if (dev->parent) {
+ res = platform_get_resource(pdev, IORESOURCE_REG, index);
+ if (!res)
+ return NULL;
+
+ return dev_get_regmap(dev->parent, res->name);
+ }
+
+ return NULL;
+}
+
+static inline struct regmap *
+ocelot_regmap_from_resource(struct platform_device *pdev, unsigned int index,
+ const struct regmap_config *config)
+{
+ struct regmap *map;
+
+ map = ocelot_regmap_from_resource_optional(pdev, index, config);
+ return map ?: ERR_PTR(-ENOENT);
+}
+
+#endif
--
2.25.1
On Wed, Aug 3, 2022 at 7:47 AM Colin Foster
<[email protected]> wrote:
>
> Several ocelot-related modules are designed for MMIO / regmaps. As such,
> they often use a combination of devm_platform_get_and_ioremap_resource()
> and devm_regmap_init_mmio().
>
> Operating in an MFD might be different, in that it could be memory mapped,
> or it could be SPI, I2C... In these cases a fallback to use IORESOURCE_REG
> instead of IORESOURCE_MEM becomes necessary.
>
> When this happens, there's redundant logic that needs to be implemented in
> every driver. In order to avoid this redundancy, utilize a single function
> that, if the MFD scenario is enabled, will perform this fallback logic.
FWIW,
Reviewed-by: Andy Shevchenko <[email protected]>
> Signed-off-by: Colin Foster <[email protected]>
> Reviewed-by: Vladimir Oltean <[email protected]>
> ---
>
> v15
> * Add missed errno.h and ioport.h includes
> * Add () to function references in both the commit log and comments
>
> v14
> * Add header guard
> * Change regs type from u32* to void*
> * Add Reviewed-by tag
>
> ---
> MAINTAINERS | 5 +++
> include/linux/mfd/ocelot.h | 62 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 67 insertions(+)
> create mode 100644 include/linux/mfd/ocelot.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 28108e4fdb8f..f781caceeb38 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14467,6 +14467,11 @@ F: net/dsa/tag_ocelot.c
> F: net/dsa/tag_ocelot_8021q.c
> F: tools/testing/selftests/drivers/net/ocelot/*
>
> +OCELOT EXTERNAL SWITCH CONTROL
> +M: Colin Foster <[email protected]>
> +S: Supported
> +F: include/linux/mfd/ocelot.h
> +
> OCXL (Open Coherent Accelerator Processor Interface OpenCAPI) DRIVER
> M: Frederic Barrat <[email protected]>
> M: Andrew Donnellan <[email protected]>
> diff --git a/include/linux/mfd/ocelot.h b/include/linux/mfd/ocelot.h
> new file mode 100644
> index 000000000000..dd72073d2d4f
> --- /dev/null
> +++ b/include/linux/mfd/ocelot.h
> @@ -0,0 +1,62 @@
> +/* SPDX-License-Identifier: GPL-2.0 OR MIT */
> +/* Copyright 2022 Innovative Advantage Inc. */
> +
> +#ifndef _LINUX_MFD_OCELOT_H
> +#define _LINUX_MFD_OCELOT_H
> +
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/ioport.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>
> +
> +struct resource;
> +
> +static inline struct regmap *
> +ocelot_regmap_from_resource_optional(struct platform_device *pdev,
> + unsigned int index,
> + const struct regmap_config *config)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *res;
> + void __iomem *regs;
> +
> + /*
> + * Don't use _get_and_ioremap_resource() here, since that will invoke
> + * prints of "invalid resource" which will simply add confusion.
> + */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, index);
> + if (res) {
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs))
> + return ERR_CAST(regs);
> + return devm_regmap_init_mmio(dev, regs, config);
> + }
> +
> + /*
> + * Fall back to using REG and getting the resource from the parent
> + * device, which is possible in an MFD configuration
> + */
> + if (dev->parent) {
> + res = platform_get_resource(pdev, IORESOURCE_REG, index);
> + if (!res)
> + return NULL;
> +
> + return dev_get_regmap(dev->parent, res->name);
> + }
> +
> + return NULL;
> +}
> +
> +static inline struct regmap *
> +ocelot_regmap_from_resource(struct platform_device *pdev, unsigned int index,
> + const struct regmap_config *config)
> +{
> + struct regmap *map;
> +
> + map = ocelot_regmap_from_resource_optional(pdev, index, config);
> + return map ?: ERR_PTR(-ENOENT);
> +}
> +
> +#endif
> --
> 2.25.1
>
--
With Best Regards,
Andy Shevchenko