Re: [RFC PATCH v2 1/5] mfd: qpnp: add support for Qualcomm QPNP PMICs

[Lee Jones <lee.jones@linaro.org>]

On Thu, 03 Jul 2014, Stanimir Varbanov wrote:
> From: Josh Cartwright <joshc@codeaurora.org>
> 
> The Qualcomm QPNP PMIC chips are components used with the
> Snapdragon 800 series SoC family.  This driver exists
> largely as a glue mfd component, it exists to be an owner
> of an SPMI regmap for children devices described in
> device tree.
> 
> Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> ---
>  drivers/mfd/Kconfig     |   15 ++++++
>  drivers/mfd/Makefile    |    1 +
>  drivers/mfd/qpnp-spmi.c |  129 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 145 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/mfd/qpnp-spmi.c
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index ee8204c..258b733 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -524,6 +524,21 @@ config MFD_PM8921_CORE
>  	  Say M here if you want to include support for PM8921 chip as a module.
>  	  This will build a module called "pm8921-core".
>  
> +config MFD_QPNP_SPMI
> +	tristate "Qualcomm QPNP SPMI PMIC"
> +	depends on ARCH_QCOM || COMPILE_TEST
> +	depends on OF
> +	select MFD_CORE
> +	select REGMAP_SPMI
> +	help
> +	  This enables support for the Qualcomm QPNP SPMI PMICs.
> +	  These PMICs are currently used with the Snapdragon 800 series of
> +	  SoCs.  Note, that this will only be useful paired with descriptions
> +	  of the independent functions as children nodes in the device tree.

It would be helpful if the expected types of child devices were
mentioned here in the help section.

> +	  Say M here if you want to include support for the QPNP SPMI PMIC
> +	  series as a module.  The module will be called "qpnp-spmi".
> +
>  config MFD_RDC321X
>  	tristate "RDC R-321x southbridge"
>  	select MFD_CORE
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 8afedba..31833d7 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -153,6 +153,7 @@ obj-$(CONFIG_MFD_SI476X_CORE)	+= si476x-core.o
>  obj-$(CONFIG_MFD_CS5535)	+= cs5535-mfd.o
>  obj-$(CONFIG_MFD_OMAP_USB_HOST)	+= omap-usb-host.o omap-usb-tll.o
>  obj-$(CONFIG_MFD_PM8921_CORE) 	+= pm8921-core.o ssbi.o
> +obj-$(CONFIG_MFD_QPNP_SPMI)	+= qpnp-spmi.o
>  obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
>  obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
>  obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
> diff --git a/drivers/mfd/qpnp-spmi.c b/drivers/mfd/qpnp-spmi.c
> new file mode 100644
> index 0000000..efd7d3e
> --- /dev/null
> +++ b/drivers/mfd/qpnp-spmi.c
> @@ -0,0 +1,129 @@
> +/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
> + *

Non-standard multi-line comment.  First line should be blank.

> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.

No author?

> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/spmi.h>
> +#include <linux/regmap.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +#include <linux/mfd/core.h>
> +
> +#define QPNP_RESOURCE_SIZE	256
> +
> +static const struct regmap_config qpnp_regmap_config = {
> +	.reg_bits	= 16,
> +	.val_bits	= 8,
> +	.max_register	= 0xffff,
> +};
> +
> +static int qpnp_index_to_resource(struct device_node *np, int index,
> +				  struct resource *res)
> +{
> +	const char *name = NULL;
> +	const __be32 *addrp;
> +	u64 addr;
> +
> +	addrp = of_get_address(np, index, NULL, NULL);
> +	if (!addrp)
> +		return -EINVAL;
> +
> +	addr = of_read_number(addrp, 1);
> +	if (addr == OF_BAD_ADDR)
> +		return -EINVAL;
> +
> +	of_property_read_string_index(np, "reg-names", index, &name);
> +
> +	res->start = addr;
> +	res->end = addr + QPNP_RESOURCE_SIZE - 1;
> +	res->flags = IORESOURCE_REG;
> +	res->name = name ? name : np->name;
> +
> +	return 0;
> +}
> +
> +static int qpnp_add_device(struct spmi_device *root, struct device_node *child)
> +{
> +	struct mfd_cell cell = {};
> +	struct resource *res, *r;
> +	int num_resources = 0;
> +	const char *compat;
> +	int ret, i;
> +
> +	compat = of_get_property(child, "compatible", NULL);
> +	if (!compat)
> +		return -ENODEV;
> +
> +	while (of_get_address(child, num_resources, NULL, NULL))
> +		num_resources++;
> +
> +	if (!num_resources)
> +		return -ENODEV;
> +
> +	res = kcalloc(num_resources, sizeof(*res), GFP_KERNEL);
> +	if (!res)
> +		return -ENOMEM;
> +
> +	r = res;
> +	for (i = 0; i < num_resources; i++, r++)
> +		qpnp_index_to_resource(child, i, r);
> +
> +	cell.name = kasprintf(GFP_KERNEL, "%x.%04x.%s", root->usid,
> +			      (u16)res[0].start, child->name);
> +	cell.of_compatible = compat;
> +	cell.num_resources = num_resources;
> +	cell.resources = res;
> +
> +	ret = mfd_add_devices(&root->dev, PLATFORM_DEVID_NONE, &cell, 1,
> +			      NULL, 0, NULL);
> +
> +	kfree(res);
> +	kfree(cell.name);
> +
> +	return ret;
> +}
> +
> +static int qpnp_probe(struct spmi_device *sdev)
> +{
> +	struct device_node *root = sdev->dev.of_node;
> +	struct device_node *child;
> +	struct regmap *regmap;
> +
> +	regmap = devm_regmap_init_spmi_ext(sdev, &qpnp_regmap_config);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	for_each_available_child_of_node(root, child)
> +		qpnp_add_device(sdev, child);

This entire driver looks like a re-write of of_platform_populate().

Why?

> +	return 0;
> +}
> +
> +static void qpnp_remove(struct spmi_device *sdev)
> +{
> +	mfd_remove_devices(&sdev->dev);
> +}
> +
> +static const struct of_device_id qpnp_id_table[] = {
> +	{ .compatible = "qcom,qpnp-spmi", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, qpnp_id_table);
> +
> +static struct spmi_driver qpnp_driver = {
> +	.probe = qpnp_probe,
> +	.remove = qpnp_remove,
> +	.driver = {
> +		.name = "qpnp-spmi",
> +		.of_match_table = qpnp_id_table,
> +	},
> +};
> +module_spmi_driver(qpnp_driver);

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog