Messages in this thread | | | Date | Thu, 14 Feb 2019 09:34:45 +0000 | From | Lee Jones <> | Subject | Re: [RFC 2/6] mfd: Support for Ettus Research E31x devices PMU |
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On Mon, 11 Feb 2019, Virendra Kakade wrote:
> Signed-off-by: Virendra Kakade <virendra.kakade@ni.com> > --- > drivers/mfd/Kconfig | 7 +++ > drivers/mfd/Makefile | 2 +- > drivers/mfd/e31x-pmu.c | 89 ++++++++++++++++++++++++++++++++++++ > include/linux/mfd/e31x-pmu.h | 20 ++++++++ > 4 files changed, 117 insertions(+), 1 deletion(-) > create mode 100644 drivers/mfd/e31x-pmu.c > create mode 100644 include/linux/mfd/e31x-pmu.h > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index 8c5dfdce4326..6c4c0747f2a5 100644 > --- a/drivers/mfd/Kconfig > +++ b/drivers/mfd/Kconfig > @@ -1916,4 +1916,11 @@ config RAVE_SP_CORE > device found on several devices in RAVE line of hardware. > > endmenu > + > +config MFD_E31X_PMU > + tristate "E31X PMU driver" > + select MFD_SYSCON > + help > + Select this to get support for the Ettus Research E31x devices. > + > endif > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > index 12980a4ad460..e37c2057134b 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -241,4 +241,4 @@ obj-$(CONFIG_MFD_MXS_LRADC) += mxs-lradc.o > obj-$(CONFIG_MFD_SC27XX_PMIC) += sprd-sc27xx-spi.o > obj-$(CONFIG_RAVE_SP_CORE) += rave-sp.o > obj-$(CONFIG_MFD_ROHM_BD718XX) += rohm-bd718x7.o > - > +obj-$(CONFIG_MFD_E31X_PMU) += e31x-pmu.o > diff --git a/drivers/mfd/e31x-pmu.c b/drivers/mfd/e31x-pmu.c > new file mode 100644 > index 000000000000..383df68a538f > --- /dev/null > +++ b/drivers/mfd/e31x-pmu.c > @@ -0,0 +1,89 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2018 National Instruments Corp
This is out of date.
'\n' here.
> + * Author: Virendra Kakade<virendra.kakade@ni.com>
You need a space after your name.
> + * Ettus Research E31x PMU MFD driver
Please expand PMU.
> + */ > + > +#include <linux/err.h> > +#include <linux/delay.h> > +#include <linux/interrupt.h> > +#include <linux/kernel.h> > +#include <linux/mfd/syscon.h> > +#include <linux/module.h> > +#include <linux/pm_runtime.h> > +#include <linux/regmap.h> > +#include <linux/mfd/core.h> > +#include <linux/of_device.h> > +#include <linux/mfd/e31x-pmu.h> > +#include <linux/platform_device.h>
Alphabetical.
> +#define E31X_PMU_MISC_IRQ_MASK BIT(8) > +#define E31X_PMU_MISC_IRQ_SHIFT 8 > +#define E31X_PMU_MISC_VERSION_MIN_MASK GENMASK(3, 0) > +#define E31X_PMU_MISC_VERSION_MIN_SHIFT 0 > +#define E31X_PMU_MISC_VERSION_MAJ_MASK GENMASK(7, 4) > +#define E31X_PMU_MISC_VERSION_MAJ_SHIFT 4 > + > +struct e31x_pmu { > + struct regmap *regmap; > +};
A whole struct for one attribute?
> +static int e31x_pmu_check_version(struct e31x_pmu *pmu) > +{ > + int timeout = 100;
Where does 100 come from?
> + u32 misc, maj; > + int err;
'ret' is more common.
> + /* we need to wait a bit for firmware to populate the fields */
"a bit" ?
What does the datasheet say?
Please use proper grammar. Capital letters.
> + while (timeout--) { > + err = regmap_read(pmu->regmap, E31X_PMU_REG_MISC, &misc); > + if (err) > + return err; > + if (misc) > + break; > + > + usleep_range(2500, 5000);
Formatting.
> + } > + > + /* only firmware versions above 2.0 are supported */
"Only supports firmware version 2.0 and above"
> + maj = E31X_PMU_GET_FIELD(MISC_VERSION_MAJ, misc); > + if (maj < 2) > + return -ENOTSUPP;
'\n' here.
> + return 0; > +} > + > +static int e31x_pmu_probe(struct platform_device *pdev) > +{ > + struct e31x_pmu *pmu; > + > + pmu = devm_kzalloc(&pdev->dev, sizeof(*pmu), GFP_KERNEL); > + if (!pmu) > + return -ENOMEM;
'\n' here.
> + pmu->regmap = syscon_regmap_lookup_by_phandle(\
Why are you storing regmap?
Just pass it directly to e31x_pmu_check_version().
> + pdev->dev.of_node, "regmap"); > +
Remove this line.
> + if (IS_ERR(pmu->regmap)) > + return PTR_ERR(pmu->regmap);
'\n' here.
> + if (e31x_pmu_check_version(pmu))
Please split out the function from the if.
Use a variable 'ret' to feed into and check that.
> + return -ENOTSUPP;
'\n' here.
> + return devm_of_platform_populate(&pdev->dev); > +} > + > +static const struct of_device_id e31x_pmu_id[] = { > + { .compatible = "ni,e31x-pmu" }, > + {}, > +}; > + > +static struct platform_driver e31x_pmu_driver = { > + .driver = { > + .name = "e31x-pmu", > + .of_match_table = e31x_pmu_id,
These 2 lines need indenting.
> + }, > + .probe = e31x_pmu_probe, > +}; > +module_platform_driver(e31x_pmu_driver); > + > +MODULE_DESCRIPTION("E31x PMU driver"); > +MODULE_AUTHOR("Virendra Kakade <virendra.kakade@ni.com>"); > +MODULE_LICENSE("GPL");
So the whole purpose of this driver is to do a version check.
Seems like over-kill!
Probably better to do the version check in an inline function stored in a header file, then call it from each of the children's .probe() function.
> diff --git a/include/linux/mfd/e31x-pmu.h b/include/linux/mfd/e31x-pmu.h > new file mode 100644 > index 000000000000..c57d5a8c1aad > --- /dev/null > +++ b/include/linux/mfd/e31x-pmu.h > @@ -0,0 +1,20 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2018 National Instruments Corp
Out of date.
'\n' here.
> + * Author: Virendra Kakade <virendra.kakade@ni.com> > + * > + * Ettus Research E31x PMU constants > + */ > + > +#ifndef MFD_E31X_PMU_H > +#define MFD_E31X_PMU_H > + > +#include <linux/bitops.h> > + > +#define E31X_PMU_REG_MISC 0x04 > + > +#define E31X_PMU_GET_FIELD(name, reg) \ > + (((reg) & E31X_PMU_## name ##_MASK) >> \ > + E31X_PMU_## name ##_SHIFT) > + > +#endif /* MFD_E31X_PMU_H */
-- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
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