[3/5] i2c: riic: Add RZ/G2L support

Message ID 20210611165624.30749-4-biju.das.jz@bp.renesas.com
State New
Headers show
Series
  • Add RZ/G2L I2C support
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Commit Message

Biju Das June 11, 2021, 4:56 p.m.
RZ/G2L i2c controller is compatible with RZ/A i2c controller.
By default IP is in reset state, so need to perform release
reset before accessing any register.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/i2c/busses/Kconfig    |  1 +
 drivers/i2c/busses/i2c-riic.c | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

Comments

Geert Uytterhoeven June 14, 2021, 12:38 p.m. | #1
Hi Biju,

On Fri, Jun 11, 2021 at 6:56 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> RZ/G2L i2c controller is compatible with RZ/A i2c controller.

> By default IP is in reset state, so need to perform release

> reset before accessing any register.

>

> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>

> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>


Thanks for your patch!

> --- a/drivers/i2c/busses/Kconfig

> +++ b/drivers/i2c/busses/Kconfig

> @@ -941,6 +941,7 @@ config I2C_QUP

>  config I2C_RIIC

>         tristate "Renesas RIIC adapter"

>         depends on ARCH_RENESAS || COMPILE_TEST

> +       select RESET_CONTROLLER


if ARCH_R9A07G044?

> --- a/drivers/i2c/busses/i2c-riic.c

> +++ b/drivers/i2c/busses/i2c-riic.c

_kzalloc(&pdev->dev, sizeof(*riic), GFP_KERNEL);
>         if (!riic)

> @@ -412,6 +421,17 @@ static int riic_i2c_probe(struct platform_device *pdev)

>                 return PTR_ERR(riic->clk);

>         }

>

> +       type = (enum riic_type)of_device_get_match_data(&pdev->dev);

> +       if (type == RIIC_RZ_G2L) {

> +               rstc = devm_reset_control_get(&pdev->dev, NULL);

> +               if (IS_ERR(rstc)) {

> +                       dev_err(&pdev->dev, "Error: missing reset ctrl\n");

> +                       return PTR_ERR(rstc);

> +               }

> +

> +               reset_control_deassert(rstc);


Just wondering: does it harm if the driver is unloaded or unbounded,
and rebound while the I2C controller is not in reset state?

> +       }

> +

>         for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {

>                 res = platform_get_resource(pdev, IORESOURCE_IRQ, riic_irqs[i].res_num);

>                 if (!res)

> @@ -472,6 +492,7 @@ static int riic_i2c_remove(struct platform_device *pdev)

>  }

>

>  static const struct of_device_id riic_i2c_dt_ids[] = {

> +       { .compatible = "renesas,riic-r9a07g044", .data = (void *)RIIC_RZ_G2L },

>         { .compatible = "renesas,riic-rz" },


Please fill in .data, to avoid relying implicitly on RIIC_RZ_A being zero.

>         { /* Sentinel */ },

>  };


Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
Philipp Zabel June 14, 2021, 1:27 p.m. | #2
Hi Biju,

On Fri, 2021-06-11 at 17:56 +0100, Biju Das wrote:
> RZ/G2L i2c controller is compatible with RZ/A i2c controller.

> By default IP is in reset state, so need to perform release

> reset before accessing any register.

> 

> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>

> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

> ---

>  drivers/i2c/busses/Kconfig    |  1 +

>  drivers/i2c/busses/i2c-riic.c | 21 +++++++++++++++++++++

>  2 files changed, 22 insertions(+)

> 

> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig

> index 281a65d9b44b..5da09288b461 100644

> --- a/drivers/i2c/busses/Kconfig

> +++ b/drivers/i2c/busses/Kconfig

> @@ -941,6 +941,7 @@ config I2C_QUP

>  config I2C_RIIC

>  	tristate "Renesas RIIC adapter"

>  	depends on ARCH_RENESAS || COMPILE_TEST

> +	select RESET_CONTROLLER


There's no need for this. The reset API defines inline stubs so this can
be compiled without RESET_CONTROLLER enabled.

>  	help

>  	  If you say yes to this option, support will be included for the

>  	  Renesas RIIC I2C interface.

> diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c

> index 4eccc0f69861..a3860631c6db 100644

> --- a/drivers/i2c/busses/i2c-riic.c

> +++ b/drivers/i2c/busses/i2c-riic.c

> @@ -42,8 +42,10 @@

>  #include <linux/io.h>

>  #include <linux/module.h>

>  #include <linux/of.h>

> +#include <linux/of_device.h>

>  #include <linux/platform_device.h>

>  #include <linux/pm_runtime.h>

> +#include <linux/reset.h>

>  

>  #define RIIC_ICCR1	0x00

>  #define RIIC_ICCR2	0x04

> @@ -86,6 +88,11 @@

>  

>  #define RIIC_INIT_MSG	-1

>  

> +enum riic_type {

> +	RIIC_RZ_A,

> +	RIIC_RZ_G2L,

> +};

> +

>  struct riic_dev {

>  	void __iomem *base;

>  	u8 *buf;

> @@ -395,7 +402,9 @@ static int riic_i2c_probe(struct platform_device *pdev)

>  	struct i2c_adapter *adap;

>  	struct resource *res;

>  	struct i2c_timings i2c_t;

> +	struct reset_control *rstc;

>  	int i, ret;

> +	enum riic_type type;

>  

>  	riic = devm_kzalloc(&pdev->dev, sizeof(*riic), GFP_KERNEL);

>  	if (!riic)

> @@ -412,6 +421,17 @@ static int riic_i2c_probe(struct platform_device *pdev)

>  		return PTR_ERR(riic->clk);

>  	}

>  

> +	type = (enum riic_type)of_device_get_match_data(&pdev->dev);

> +	if (type == RIIC_RZ_G2L) {

> +		rstc = devm_reset_control_get(&pdev->dev, NULL);


Please use devm_reset_control_get_exclusive().

> +		if (IS_ERR(rstc)) {

> +			dev_err(&pdev->dev, "Error: missing reset ctrl\n");

> +			return PTR_ERR(rstc);

> +		}

> +

> +		reset_control_deassert(rstc);

> +	}

> +

>  	for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {

>  		res = platform_get_resource(pdev, IORESOURCE_IRQ, riic_irqs[i].res_num);

>  		if (!res)

> @@ -472,6 +492,7 @@ static int riic_i2c_remove(struct platform_device *pdev)

>  }

>  

>  static const struct of_device_id riic_i2c_dt_ids[] = {

> +	{ .compatible = "renesas,riic-r9a07g044", .data = (void *)RIIC_RZ_G2L },

>  	{ .compatible = "renesas,riic-rz" },

>  	{ /* Sentinel */ },

>  };


regards
Philipp
Geert Uytterhoeven June 14, 2021, 1:38 p.m. | #3
Hi Philipp,

On Mon, Jun 14, 2021 at 3:27 PM Philipp Zabel <p.zabel@pengutronix.de> wrote:
> On Fri, 2021-06-11 at 17:56 +0100, Biju Das wrote:

> > RZ/G2L i2c controller is compatible with RZ/A i2c controller.

> > By default IP is in reset state, so need to perform release

> > reset before accessing any register.

> >

> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>

> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

> > ---

> >  drivers/i2c/busses/Kconfig    |  1 +

> >  drivers/i2c/busses/i2c-riic.c | 21 +++++++++++++++++++++

> >  2 files changed, 22 insertions(+)

> >

> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig

> > index 281a65d9b44b..5da09288b461 100644

> > --- a/drivers/i2c/busses/Kconfig

> > +++ b/drivers/i2c/busses/Kconfig

> > @@ -941,6 +941,7 @@ config I2C_QUP

> >  config I2C_RIIC

> >       tristate "Renesas RIIC adapter"

> >       depends on ARCH_RENESAS || COMPILE_TEST

> > +     select RESET_CONTROLLER

>

> There's no need for this. The reset API defines inline stubs so this can

> be compiled without RESET_CONTROLLER enabled.


AFAIK, the issue is that RIIC on RZ/G2L requires reset support,
so it must be enabled when building a kernel for RZ/G2L.
As RZ/A does not need or use it, and may run from SRAM, I'd like to
leave it disabled when building a kernel not including RZ/G2L support.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
Biju Das June 14, 2021, 4:04 p.m. | #4
Hi Geert,

Thanks for the feedback.

> -----Original Message-----

> Subject: Re: [PATCH 3/5] i2c: riic: Add RZ/G2L support

> 

> Hi Biju,

> 

> On Fri, Jun 11, 2021 at 6:56 PM Biju Das <biju.das.jz@bp.renesas.com>

> wrote:

> > RZ/G2L i2c controller is compatible with RZ/A i2c controller.

> > By default IP is in reset state, so need to perform release reset

> > before accessing any register.

> >

> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>

> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

> 

> Thanks for your patch!

> 

> > --- a/drivers/i2c/busses/Kconfig

> > +++ b/drivers/i2c/busses/Kconfig

> > @@ -941,6 +941,7 @@ config I2C_QUP

> >  config I2C_RIIC

> >         tristate "Renesas RIIC adapter"

> >         depends on ARCH_RENESAS || COMPILE_TEST

> > +       select RESET_CONTROLLER

> 

> if ARCH_R9A07G044?


OK,Agreed.

> 

> > --- a/drivers/i2c/busses/i2c-riic.c

> > +++ b/drivers/i2c/busses/i2c-riic.c

> _kzalloc(&pdev->dev, sizeof(*riic), GFP_KERNEL);

> >         if (!riic)

> > @@ -412,6 +421,17 @@ static int riic_i2c_probe(struct platform_device

> *pdev)

> >                 return PTR_ERR(riic->clk);

> >         }

> >

> > +       type = (enum riic_type)of_device_get_match_data(&pdev->dev);

> > +       if (type == RIIC_RZ_G2L) {

> > +               rstc = devm_reset_control_get(&pdev->dev, NULL);

> > +               if (IS_ERR(rstc)) {

> > +                       dev_err(&pdev->dev, "Error: missing reset

> ctrl\n");

> > +                       return PTR_ERR(rstc);

> > +               }

> > +

> > +               reset_control_deassert(rstc);

> 

> Just wondering: does it harm if the driver is unloaded or unbounded, and

> rebound while the I2C controller is not in reset state?


I have tested and it works after unloading and reloading it again.

Cheers,
Biju

> 

> > +       }

> > +

> >         for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {

> >                 res = platform_get_resource(pdev, IORESOURCE_IRQ,

> riic_irqs[i].res_num);

> >                 if (!res)

> > @@ -472,6 +492,7 @@ static int riic_i2c_remove(struct platform_device

> > *pdev)  }

> >

> >  static const struct of_device_id riic_i2c_dt_ids[] = {

> > +       { .compatible = "renesas,riic-r9a07g044", .data = (void

> > + *)RIIC_RZ_G2L },

> >         { .compatible = "renesas,riic-rz" },

> 

> Please fill in .data, to avoid relying implicitly on RIIC_RZ_A being zero.

> 

> >         { /* Sentinel */ },

> >  };

> 

> Gr{oetje,eeting}s,

> 

>                         Geert

> 

> --

> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-

> m68k.org

> 

> In personal conversations with technical people, I call myself a hacker.

> But when I'm talking to journalists I just say "programmer" or something

> like that.

>                                 -- Linus Torvalds
Biju Das June 14, 2021, 5:20 p.m. | #5
Hi Philipp,

Thanks for the review.

> Subject: Re: [PATCH 3/5] i2c: riic: Add RZ/G2L support

> 

> Hi Biju,

> 

> On Fri, 2021-06-11 at 17:56 +0100, Biju Das wrote:

> > RZ/G2L i2c controller is compatible with RZ/A i2c controller.

> > By default IP is in reset state, so need to perform release reset

> > before accessing any register.

> >

> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>

> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

> > ---

> >  drivers/i2c/busses/Kconfig    |  1 +

> >  drivers/i2c/busses/i2c-riic.c | 21 +++++++++++++++++++++

> >  2 files changed, 22 insertions(+)

> >

> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig

> > index 281a65d9b44b..5da09288b461 100644

> > --- a/drivers/i2c/busses/Kconfig

> > +++ b/drivers/i2c/busses/Kconfig

> > @@ -941,6 +941,7 @@ config I2C_QUP

> >  config I2C_RIIC

> >  	tristate "Renesas RIIC adapter"

> >  	depends on ARCH_RENESAS || COMPILE_TEST

> > +	select RESET_CONTROLLER

> 

> There's no need for this. The reset API defines inline stubs so this can

> be compiled without RESET_CONTROLLER enabled.


Hope you are ok with Geert's suggestion, as RZ/A boards are resource constrained.
So it is not good to enable for them.

> 

> >  	help

> >  	  If you say yes to this option, support will be included for the

> >  	  Renesas RIIC I2C interface.

> > diff --git a/drivers/i2c/busses/i2c-riic.c

> > b/drivers/i2c/busses/i2c-riic.c index 4eccc0f69861..a3860631c6db

> > 100644

> > --- a/drivers/i2c/busses/i2c-riic.c

> > +++ b/drivers/i2c/busses/i2c-riic.c

> > @@ -42,8 +42,10 @@

> >  #include <linux/io.h>

> >  #include <linux/module.h>

> >  #include <linux/of.h>

> > +#include <linux/of_device.h>

> >  #include <linux/platform_device.h>

> >  #include <linux/pm_runtime.h>

> > +#include <linux/reset.h>

> >

> >  #define RIIC_ICCR1	0x00

> >  #define RIIC_ICCR2	0x04

> > @@ -86,6 +88,11 @@

> >

> >  #define RIIC_INIT_MSG	-1

> >

> > +enum riic_type {

> > +	RIIC_RZ_A,

> > +	RIIC_RZ_G2L,

> > +};

> > +

> >  struct riic_dev {

> >  	void __iomem *base;

> >  	u8 *buf;

> > @@ -395,7 +402,9 @@ static int riic_i2c_probe(struct platform_device

> *pdev)

> >  	struct i2c_adapter *adap;

> >  	struct resource *res;

> >  	struct i2c_timings i2c_t;

> > +	struct reset_control *rstc;

> >  	int i, ret;

> > +	enum riic_type type;

> >

> >  	riic = devm_kzalloc(&pdev->dev, sizeof(*riic), GFP_KERNEL);

> >  	if (!riic)

> > @@ -412,6 +421,17 @@ static int riic_i2c_probe(struct platform_device

> *pdev)

> >  		return PTR_ERR(riic->clk);

> >  	}

> >

> > +	type = (enum riic_type)of_device_get_match_data(&pdev->dev);

> > +	if (type == RIIC_RZ_G2L) {

> > +		rstc = devm_reset_control_get(&pdev->dev, NULL);

> 

> Please use devm_reset_control_get_exclusive().


OK. Will do.

Regards,
Biju

> 

> > +		if (IS_ERR(rstc)) {

> > +			dev_err(&pdev->dev, "Error: missing reset ctrl\n");

> > +			return PTR_ERR(rstc);

> > +		}

> > +

> > +		reset_control_deassert(rstc);

> > +	}

> > +

> >  	for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {

> >  		res = platform_get_resource(pdev, IORESOURCE_IRQ,

> riic_irqs[i].res_num);

> >  		if (!res)

> > @@ -472,6 +492,7 @@ static int riic_i2c_remove(struct platform_device

> > *pdev)  }

> >

> >  static const struct of_device_id riic_i2c_dt_ids[] = {

> > +	{ .compatible = "renesas,riic-r9a07g044", .data = (void

> > +*)RIIC_RZ_G2L },

> >  	{ .compatible = "renesas,riic-rz" },

> >  	{ /* Sentinel */ },

> >  };

> 

> regards

> Philipp

Patch

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 281a65d9b44b..5da09288b461 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -941,6 +941,7 @@  config I2C_QUP
 config I2C_RIIC
 	tristate "Renesas RIIC adapter"
 	depends on ARCH_RENESAS || COMPILE_TEST
+	select RESET_CONTROLLER
 	help
 	  If you say yes to this option, support will be included for the
 	  Renesas RIIC I2C interface.
diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index 4eccc0f69861..a3860631c6db 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -42,8 +42,10 @@ 
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 
 #define RIIC_ICCR1	0x00
 #define RIIC_ICCR2	0x04
@@ -86,6 +88,11 @@ 
 
 #define RIIC_INIT_MSG	-1
 
+enum riic_type {
+	RIIC_RZ_A,
+	RIIC_RZ_G2L,
+};
+
 struct riic_dev {
 	void __iomem *base;
 	u8 *buf;
@@ -395,7 +402,9 @@  static int riic_i2c_probe(struct platform_device *pdev)
 	struct i2c_adapter *adap;
 	struct resource *res;
 	struct i2c_timings i2c_t;
+	struct reset_control *rstc;
 	int i, ret;
+	enum riic_type type;
 
 	riic = devm_kzalloc(&pdev->dev, sizeof(*riic), GFP_KERNEL);
 	if (!riic)
@@ -412,6 +421,17 @@  static int riic_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(riic->clk);
 	}
 
+	type = (enum riic_type)of_device_get_match_data(&pdev->dev);
+	if (type == RIIC_RZ_G2L) {
+		rstc = devm_reset_control_get(&pdev->dev, NULL);
+		if (IS_ERR(rstc)) {
+			dev_err(&pdev->dev, "Error: missing reset ctrl\n");
+			return PTR_ERR(rstc);
+		}
+
+		reset_control_deassert(rstc);
+	}
+
 	for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {
 		res = platform_get_resource(pdev, IORESOURCE_IRQ, riic_irqs[i].res_num);
 		if (!res)
@@ -472,6 +492,7 @@  static int riic_i2c_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id riic_i2c_dt_ids[] = {
+	{ .compatible = "renesas,riic-r9a07g044", .data = (void *)RIIC_RZ_G2L },
 	{ .compatible = "renesas,riic-rz" },
 	{ /* Sentinel */ },
 };