Re: [PATCH 3/3] soc: fsl: add RCPM driver

[Li Yang]

On Tue, Sep 4, 2018 at 9:58 PM Wang, Dongsheng
<dongsheng.wang@xxxxxxxxxxxxxxxx> wrote:
>
> Please change your comments style.

Although this doesn't get into the Linux kernel coding style
documentation yet, Linus seems changed his mind to prefer // than /*
*/ comment style now.  https://lkml.org/lkml/2017/11/25/133   So the
// style should be acceptable for now.

>
> On 2018/8/31 11:56, Ran Wang wrote:
> > The NXP's QorIQ Processors based on ARM Core have RCPM module (Run
> > Control and Power Management), which performs all device-level
> > tasks associated with power management such as wakeup source control.
> >
> > This driver depends on FSL platform PM driver framework which help to
> > isolate user and PM service provider (such as RCPM driver).
> >
> > Signed-off-by: Chenhui Zhao <chenhui.zhao@xxxxxxx>
> > Signed-off-by: Ying Zhang <ying.zhang22455@xxxxxxx>
> > Signed-off-by: Ran Wang <ran.wang_1@xxxxxxx>
> > ---
> >  drivers/soc/fsl/Kconfig   |    6 ++
> >  drivers/soc/fsl/Makefile  |    1 +
> >  drivers/soc/fsl/ls-rcpm.c |  153 +++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 160 insertions(+), 0 deletions(-)
> >  create mode 100644 drivers/soc/fsl/ls-rcpm.c
> >
> > diff --git a/drivers/soc/fsl/Kconfig b/drivers/soc/fsl/Kconfig
> > index 6517412..882330d 100644
> > --- a/drivers/soc/fsl/Kconfig
> > +++ b/drivers/soc/fsl/Kconfig
> > @@ -30,3 +30,9 @@ config FSL_PLAT_PM
> >         have to know the implement details of wakeup function it require.
> >         Besides, it is also easy for service side to upgrade its logic when
> >         design changed and remain user side unchanged.
> > +
> > +config LS_RCPM
> > +     bool "Freescale RCPM support"
> > +     depends on (FSL_PLAT_PM)
> > +     help
> > +       This feature is to enable specified wakeup source for system sleep.
> > diff --git a/drivers/soc/fsl/Makefile b/drivers/soc/fsl/Makefile
> > index 8f9db23..43ff71a 100644
> > --- a/drivers/soc/fsl/Makefile
> > +++ b/drivers/soc/fsl/Makefile
> > @@ -7,3 +7,4 @@ obj-$(CONFIG_QUICC_ENGINE)            += qe/
> >  obj-$(CONFIG_CPM)                    += qe/
> >  obj-$(CONFIG_FSL_GUTS)                       += guts.o
> >  obj-$(CONFIG_FSL_PLAT_PM)    += plat_pm.o
> > +obj-$(CONFIG_LS_RCPM)                += ls-rcpm.o

Probably use "_" instead of "-" for alignment.

> > diff --git a/drivers/soc/fsl/ls-rcpm.c b/drivers/soc/fsl/ls-rcpm.c
> > new file mode 100644
> > index 0000000..b0feb88
> > --- /dev/null
> > +++ b/drivers/soc/fsl/ls-rcpm.c
> > @@ -0,0 +1,153 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +//
> > +// plat_pm.c - Freescale Layerscape RCPM driver

The file name here is not the same as the real file name.

> > +//
> > +// Copyright 2018 NXP
> > +//
> > +// Author: Ran Wang <ran.wang_1@xxxxxxx>,

Where do you need the comma in the end?

> > +
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/of_address.h>
> > +#include <linux/slab.h>
> > +#include <soc/fsl/plat_pm.h>
> > +
> > +#define MAX_COMPATIBLE_NUM   10
> > +
> > +struct rcpm_t {
> > +     struct device *dev;
> > +     void __iomem *ippdexpcr_addr;
> > +     bool big_endian;        /* Big/Little endian of RCPM module */
> > +};
> > +
> > +// rcpm_handle - Configure RCPM reg according to wake up source request
> > +// @user_dev: pointer to user's device struct
> > +// @flag: to enable(true) or disable(false) wakeup source
> > +// @handle_priv: pointer to struct rcpm_t instance
> > +//
> > +// Return 0 on success other negative errno

Although Linus preferred this // comment style.  I'm not sure if this
will be handled correctly by the kernel-doc compiler.
https://www.kernel.org/doc/html/v4.18/doc-guide/kernel-doc.html

> > +static int rcpm_handle(struct device *user_dev, bool flag, void *handle_priv)
> > +{
> > +     struct rcpm_t *rcpm;
> > +     bool big_endian;
> > +     const char  *dev_compatible_array[MAX_COMPATIBLE_NUM];
> > +     void __iomem *ippdexpcr_addr;
> > +     u32 ippdexpcr;
> > +     u32 set_bit;
> > +     int ret, num, i;
> > +
> > +     rcpm = handle_priv;
> > +     big_endian = rcpm->big_endian;
> > +     ippdexpcr_addr = rcpm->ippdexpcr_addr;
> > +
> > +     num = device_property_read_string_array(user_dev, "compatible",
> > +                     dev_compatible_array, MAX_COMPATIBLE_NUM);
> > +     if (num < 0)
> > +             return num;
> > +
> > +     for (i = 0; i < num; i++) {
> > +             if (!device_property_present(rcpm->dev,
> > +                                     dev_compatible_array[i]))
> > +                     continue;
> > +             else {
> Remove this else.
> > +                     ret = device_property_read_u32(rcpm->dev,
> > +                                     dev_compatible_array[i], &set_bit);
> > +                     if (ret)
> > +                             return ret;
> > +
> > +                     if (!device_property_present(rcpm->dev,
> > +                                             dev_compatible_array[i]))
> This has been checked. Continue ? or return ENODEVï
> > +                             return -ENODEV;
> > +                     else {
> Remove this else.
> > +                             ret = device_property_read_u32(rcpm->dev,
> > +                                             dev_compatible_array[i], &set_bit);
> > +                             if (ret)
> > +                                     return ret;
> > +
> > +                             if (big_endian)
> > +                                     ippdexpcr = ioread32be(ippdexpcr_addr);
> > +                             else
> > +                                     ippdexpcr = ioread32(ippdexpcr_addr);
> > +
> > +                             if (flag)
> > +                                     ippdexpcr |= set_bit;
> > +                             else
> > +                                     ippdexpcr &= ~set_bit;
> > +
> > +                             if (big_endian) {
> > +                                     iowrite32be(ippdexpcr, ippdexpcr_addr);
> > +                                     ippdexpcr = ioread32be(ippdexpcr_addr);
> > +                             } else
> if (x) {
> ....
> ....
> }  else {
>
> }
> > +                                     iowrite32(ippdexpcr, ippdexpcr_addr);
> > +
> > +                             return 0;
> > +                     }
> > +             }
> > +     }
> > +
> > +     return -ENODEV;
> > +}
> > +
> > +static int ls_rcpm_probe(struct platform_device *pdev)
> > +{
> > +     struct resource *r;
> > +     struct rcpm_t *rcpm;
> > +
> > +     r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     if (!r)
> > +             return -ENODEV;
> > +
> > +     rcpm = kmalloc(sizeof(*rcpm), GFP_KERNEL);
> kzalloc is better.
> > +     if (!rcpm)
> > +             return -ENOMEM;
> > +
> > +     rcpm->big_endian = device_property_read_bool(&pdev->dev, "big-endian");
> > +
> > +     rcpm->ippdexpcr_addr = devm_ioremap_resource(&pdev->dev, r);
> > +     if (IS_ERR(rcpm->ippdexpcr_addr))
> > +             return PTR_ERR(rcpm->ippdexpcr_addr);
> > +
> > +     rcpm->dev = &pdev->dev;
> > +     platform_set_drvdata(pdev, rcpm);
> > +
> > +     return register_fsl_platform_wakeup_source(rcpm_handle, rcpm);
> > +}
> > +
> > +static int ls_rcpm_remove(struct platform_device *pdev)
> > +{
> > +     struct rcpm_t   *rcpm;
> Not need a table.
>
> Cheers,
> -Dongsheng
>
> > +
> > +     rcpm = platform_get_drvdata(pdev);
> > +     deregister_fsl_platform_wakeup_source(rcpm);
> > +     kfree(rcpm);
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct of_device_id ls_rcpm_of_match[] = {
> > +     { .compatible = "fsl,qoriq-rcpm-2.1", },
> > +     {}
> > +};
> > +MODULE_DEVICE_TABLE(of, ls_rcpm_of_match);
> > +
> > +static struct platform_driver ls_rcpm_driver = {
> > +     .driver = {
> > +             .name = "ls-rcpm",
> > +             .of_match_table = ls_rcpm_of_match,
> > +     },
> > +     .probe = ls_rcpm_probe,
> > +     .remove = ls_rcpm_remove,
> > +};
> > +
> > +static int __init ls_rcpm_init(void)
> > +{
> > +     return platform_driver_register(&ls_rcpm_driver);
> > +}
> > +subsys_initcall(ls_rcpm_init);
> > +
> > +static void __exit ls_rcpm_exit(void)
> > +{
> > +     platform_driver_unregister(&ls_rcpm_driver);
> > +}
> > +module_exit(ls_rcpm_exit);
>
>