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

Mathieu Poirier
2023-03-30T14:21:56Z

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.

> 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.