Re: [PATCH v15 mfd 1/9] mfd: ocelot: add helper to get regmap from a resource
From: Andy Shevchenko <hidden>
Date: 2022-08-03 11:32:04
Also in:
linux-arm-kernel, linux-devicetree, linux-gpio, lkml
On Wed, Aug 3, 2022 at 7:47 AM Colin Foster [off-list ref] 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 <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Colin Foster <colin.foster@in-advantage.com> Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- 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.hdiff --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 <colin.foster@in-advantage.com> +S: Supported +F: include/linux/mfd/ocelot.h + OCXL (Open Coherent Accelerator Processor Interface OpenCAPI) DRIVER M: Frederic Barrat <fbarrat@linux.ibm.com> M: Andrew Donnellan <ajd@linux.ibm.com>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