Re: [EXTERNAL] Re: [PATCH v5 3/5] soc: ti: pruss: Add pruss_cfg_read()/update() API

[Md Danish Anwar <a0501179@ti.com>]

On 30/03/23 19:51, Mathieu Poirier wrote:
> On Thu, 30 Mar 2023 at 04:00, Md Danish Anwar <a0501179@ti.com> wrote:
>>
>> Hi Mathieu,
>>
>> On 28/03/23 02:31, Mathieu Poirier wrote:
>>> On Thu, Mar 23, 2023 at 11:54:49AM +0530, MD Danish Anwar wrote:
>>>> From: Suman Anna <s-anna@ti.com>
>>>>
>>>> Add two new generic API pruss_cfg_read() and pruss_cfg_update() to
>>>> the PRUSS platform driver to read and program respectively a register
>>>> within the PRUSS CFG sub-module represented by a syscon driver.
>>>>
>>>> These APIs are internal to PRUSS driver. Various useful registers
>>>> and macros for certain register bit-fields and their values have also
>>>> been added.
>>>>
>>>> Signed-off-by: Suman Anna <s-anna@ti.com>
>>>> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>>>> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>>>> Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
>>>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>>>> ---
>>>>  drivers/soc/ti/pruss.c |   1 +
>>>>  drivers/soc/ti/pruss.h | 112 +++++++++++++++++++++++++++++++++++++++++
>>>>  2 files changed, 113 insertions(+)
>>>>  create mode 100644 drivers/soc/ti/pruss.h
>>>>
>>>
>>> This patch doesn't compile without warnings.
>>>
>>
>> I checked the warnings. Below are the warnings that I am getting for these patch.
>>
>> In file included from drivers/soc/ti/pruss.c:24:
>> drivers/soc/ti/pruss.h:103:12: warning: ‘pruss_cfg_update’ defined but not used
>> [-Wunused-function]
>>   103 | static int pruss_cfg_update(struct pruss *pruss, unsigned int reg,
>>       |            ^~~~~~~~~~~~~~~~
>> drivers/soc/ti/pruss.h:84:12: warning: ‘pruss_cfg_read’ defined but not used
>> [-Wunused-function]
>>    84 | static int pruss_cfg_read(struct pruss *pruss, unsigned int reg,
>> unsigned int *val)
>>
>> These warnings are coming because pruss_cfg_read() / update() APIs are
>> introduced in this patch but they are used later.
>>
>> One way to resolve this warning is to make this API "inline". I compiled after
>> making these APIs inline, it got compiled without any warnings.
>>
>> The other solution is to merge a user API of these APIs in this patch. Patch 4
>> and 5 introduces some APIs that uses pruss_cfg_read() / update() APIs. If we
>> squash patch 5 (as patch 5 uses both read() and update() APIs where as patch 4
>> only uses update() API) with this patch and make it a single patch where
>> pruss_cfg_read() / update() is introduced as well as used, then this warning
>> will be resolved.
>>
> 
> The proper way to do this is to introduce new APIs only when they are needed.
> 

Sure, Mathieu. I will squash this patch with patch 5 ( as it uses both update()
and read() APIs) so that these APIs are introduced and used in the same patch.

>> I still think making these APIs "inline" is a better option as these APIs
>> implement very simple one line logic and can be made inline.
>>
>> Please let me know what do you think and which approach sounds better.
>>
>>
>>>> diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
>>>> index 126b672b9b30..2fa7df667592 100644
>>>> --- a/drivers/soc/ti/pruss.c
>>>> +++ b/drivers/soc/ti/pruss.c
>>>> @@ -21,6 +21,7 @@
>>>>  #include <linux/regmap.h>
>>>>  #include <linux/remoteproc.h>
>>>>  #include <linux/slab.h>
>>>> +#include "pruss.h"
>>>>
>>>>  /**
>>>>   * struct pruss_private_data - PRUSS driver private data
>>>> diff --git a/drivers/soc/ti/pruss.h b/drivers/soc/ti/pruss.h
>>>> new file mode 100644
>>>> index 000000000000..4626d5f6b874
>>>> --- /dev/null
>>>> +++ b/drivers/soc/ti/pruss.h
>>>> @@ -0,0 +1,112 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>>> +/*
>>>> + * PRU-ICSS Subsystem user interfaces
>>>> + *
>>>> + * Copyright (C) 2015-2023 Texas Instruments Incorporated - http://www.ti.com
>>>> + *  MD Danish Anwar <danishanwar@ti.com>
>>>> + */
>>>> +
>>>> +#ifndef _SOC_TI_PRUSS_H_
>>>> +#define _SOC_TI_PRUSS_H_
>>>> +
>>>> +#include <linux/bits.h>
>>>> +#include <linux/regmap.h>
>>>> +
>>>> +/*
>>>> + * PRU_ICSS_CFG registers
>>>> + * SYSCFG, ISRP, ISP, IESP, IECP, SCRP applicable on AMxxxx devices only
>>>> + */
>>>> +#define PRUSS_CFG_REVID         0x00
>>>> +#define PRUSS_CFG_SYSCFG        0x04
>>>> +#define PRUSS_CFG_GPCFG(x)      (0x08 + (x) * 4)
>>>> +#define PRUSS_CFG_CGR           0x10
>>>> +#define PRUSS_CFG_ISRP          0x14
>>>> +#define PRUSS_CFG_ISP           0x18
>>>> +#define PRUSS_CFG_IESP          0x1C
>>>> +#define PRUSS_CFG_IECP          0x20
>>>> +#define PRUSS_CFG_SCRP          0x24
>>>> +#define PRUSS_CFG_PMAO          0x28
>>>> +#define PRUSS_CFG_MII_RT        0x2C
>>>> +#define PRUSS_CFG_IEPCLK        0x30
>>>> +#define PRUSS_CFG_SPP           0x34
>>>> +#define PRUSS_CFG_PIN_MX        0x40
>>>> +
>>>> +/* PRUSS_GPCFG register bits */
>>>> +#define PRUSS_GPCFG_PRU_GPO_SH_SEL              BIT(25)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_DIV1_SHIFT              20
>>>> +#define PRUSS_GPCFG_PRU_DIV1_MASK               GENMASK(24, 20)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_DIV0_SHIFT              15
>>>> +#define PRUSS_GPCFG_PRU_DIV0_MASK               GENMASK(15, 19)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_GPO_MODE                BIT(14)
>>>> +#define PRUSS_GPCFG_PRU_GPO_MODE_DIRECT         0
>>>> +#define PRUSS_GPCFG_PRU_GPO_MODE_SERIAL         BIT(14)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_GPI_SB                  BIT(13)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_GPI_DIV1_SHIFT          8
>>>> +#define PRUSS_GPCFG_PRU_GPI_DIV1_MASK           GENMASK(12, 8)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_GPI_DIV0_SHIFT          3
>>>> +#define PRUSS_GPCFG_PRU_GPI_DIV0_MASK           GENMASK(7, 3)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_GPI_CLK_MODE_POSITIVE   0
>>>> +#define PRUSS_GPCFG_PRU_GPI_CLK_MODE_NEGATIVE   BIT(2)
>>>> +#define PRUSS_GPCFG_PRU_GPI_CLK_MODE            BIT(2)
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_GPI_MODE_MASK           GENMASK(1, 0)
>>>> +#define PRUSS_GPCFG_PRU_GPI_MODE_SHIFT          0
>>>> +
>>>> +#define PRUSS_GPCFG_PRU_MUX_SEL_SHIFT           26
>>>> +#define PRUSS_GPCFG_PRU_MUX_SEL_MASK            GENMASK(29, 26)
>>>> +
>>>> +/* PRUSS_MII_RT register bits */
>>>> +#define PRUSS_MII_RT_EVENT_EN                   BIT(0)
>>>> +
>>>> +/* PRUSS_SPP register bits */
>>>> +#define PRUSS_SPP_XFER_SHIFT_EN                 BIT(1)
>>>> +#define PRUSS_SPP_PRU1_PAD_HP_EN                BIT(0)
>>>> +#define PRUSS_SPP_RTU_XFR_SHIFT_EN              BIT(3)
>>>> +
>>>> +/**
>>>> + * pruss_cfg_read() - read a PRUSS CFG sub-module register
>>>> + * @pruss: the pruss instance handle
>>>> + * @reg: register offset within the CFG sub-module
>>>> + * @val: pointer to return the value in
>>>> + *
>>>> + * Reads a given register within the PRUSS CFG sub-module and
>>>> + * returns it through the passed-in @val pointer
>>>> + *
>>>> + * Return: 0 on success, or an error code otherwise
>>>> + */
>>>> +static int pruss_cfg_read(struct pruss *pruss, unsigned int reg, unsigned int *val)
>>>> +{
>>>> +    if (IS_ERR_OR_NULL(pruss))
>>>> +            return -EINVAL;
>>>> +
>>>> +    return regmap_read(pruss->cfg_regmap, reg, val);
>>>> +}
>>>> +
>>>> +/**
>>>> + * pruss_cfg_update() - configure a PRUSS CFG sub-module register
>>>> + * @pruss: the pruss instance handle
>>>> + * @reg: register offset within the CFG sub-module
>>>> + * @mask: bit mask to use for programming the @val
>>>> + * @val: value to write
>>>> + *
>>>> + * Programs a given register within the PRUSS CFG sub-module
>>>> + *
>>>> + * Return: 0 on success, or an error code otherwise
>>>> + */
>>>> +static int pruss_cfg_update(struct pruss *pruss, unsigned int reg,
>>>> +                        unsigned int mask, unsigned int val)
>>>> +{
>>>> +    if (IS_ERR_OR_NULL(pruss))
>>>> +            return -EINVAL;
>>>> +
>>>> +    return regmap_update_bits(pruss->cfg_regmap, reg, mask, val);
>>>> +}
>>>> +
>>>> +#endif  /* _SOC_TI_PRUSS_H_ */
>>>> --
>>>> 2.25.1
>>>>
>>
>> --
>> Thanks and Regards,
>> Danish.

-- 
Thanks and Regards,
Danish.