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]>
---
v14
* Add header guard
* Change regs type from u32* to void*
* Add Reviewed-by tag
---
MAINTAINERS | 5 ++++
include/linux/mfd/ocelot.h | 60 ++++++++++++++++++++++++++++++++++++++
2 files changed, 65 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..7abca80ba7dc
--- /dev/null
+++ b/include/linux/mfd/ocelot.h
@@ -0,0 +1,60 @@
+/* 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/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 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 Fri, Jul 22, 2022 at 6:06 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.
When we refer to functions we put it like func().
> 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.
...
> +#include <linux/err.h>
You also missed errno.h
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/types.h>
...
> +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
_get_and_ioremap_resource()
> + * prints of "invalid resource" which simply add confusion
> + */
will simply add
Missed period.
> + res = platform_get_resource(pdev, IORESOURCE_MEM, index);
Where are the IORESOURCE_* defined? Haven't you missed a header?
> + 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;
> +}
--
With Best Regards,
Andy Shevchenko
Hi Andy,
Great catches as always. Thank you.
I'll wait for Lee to take a look before blasting out another version.
I'm still holding out hope for this upcoming merge window!
On Mon, 25 Jul 2022, Colin Foster wrote:
> Hi Andy,
>
> Great catches as always. Thank you.
>
> I'll wait for Lee to take a look before blasting out another version.
> I'm still holding out hope for this upcoming merge window!
No chance. :)
Please submit the latest version.
--
Lee Jones [李琼斯]
Principal Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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