On RZ/G2L devices should be explicitly pulled out of reset for it
to work. This patch adds support to read the "resets" property and
performs deassert/assert when required.
Also, propagate the error to the caller of sci_parse_dt() instead of
returning NULL in case of failure.
Signed-off-by: Lad Prabhakar <[email protected]>
Reviewed-by: Biju Das <[email protected]>
---
Hi Geert,
For handling the resets I was in dual mind whether to perform
reset based on compatible strings or soc-id, let me know your
thoughts. Currently no SoC's use "renesas,sci" so using the same
for performing the reset operation for SCI.
---
drivers/tty/serial/sh-sci.c | 50 +++++++++++++++++++++++++++++++------
1 file changed, 43 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 89ee43061d3a..a0f68b887e29 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -37,6 +37,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/scatterlist.h>
#include <linux/serial.h>
#include <linux/serial_sci.h>
@@ -3203,23 +3204,58 @@ static const struct of_device_id of_sci_match[] = {
};
MODULE_DEVICE_TABLE(of, of_sci_match);
+static void sci_reset_control_assert(void *data)
+{
+ reset_control_assert(data);
+}
+
static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
unsigned int *dev_id)
{
struct device_node *np = pdev->dev.of_node;
+ const struct of_device_id *of_id;
struct plat_sci_port *p;
struct sci_port *sp;
const void *data;
int id;
if (!IS_ENABLED(CONFIG_OF) || !np)
- return NULL;
+ return ERR_PTR(-EINVAL);
+
+ of_id = of_match_device(of_sci_match, &pdev->dev);
+ if (!of_id)
+ return ERR_PTR(-EINVAL);
- data = of_device_get_match_data(&pdev->dev);
+ if (!strcmp(of_id->compatible, "renesas,scif-r9a07g044") ||
+ !strcmp(of_id->compatible, "renesas,sci")) {
+ struct reset_control *rstc;
+ int ret;
+
+ rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(rstc)) {
+ dev_err(&pdev->dev, "Error: missing reset ctrl\n");
+ return ERR_PTR(PTR_ERR(rstc));
+ }
+
+ ret = reset_control_deassert(rstc);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to deassert %d\n", ret);
+ return ERR_PTR(ret);
+ }
+
+ ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
+ ret);
+ return ERR_PTR(ret);
+ }
+ }
+
+ data = of_id->data;
p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
if (!p)
- return NULL;
+ return ERR_PTR(-ENOMEM);
/* Get the line number from the aliases node. */
id = of_alias_get_id(np, "serial");
@@ -3227,11 +3263,11 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
id = ffz(sci_ports_in_use);
if (id < 0) {
dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
- return NULL;
+ return ERR_PTR(-EINVAL);
}
if (id >= ARRAY_SIZE(sci_ports)) {
dev_err(&pdev->dev, "serial%d out of range\n", id);
- return NULL;
+ return ERR_PTR(-EINVAL);
}
sp = &sci_ports[id];
@@ -3318,8 +3354,8 @@ static int sci_probe(struct platform_device *dev)
if (dev->dev.of_node) {
p = sci_parse_dt(dev, &dev_id);
- if (p == NULL)
- return -EINVAL;
+ if (IS_ERR(p))
+ return PTR_ERR(p);
} else {
p = dev->dev.platform_data;
if (p == NULL) {
--
2.17.1
Hi Prabhakar,
On Wed, Nov 3, 2021 at 6:31 PM Lad Prabhakar
<[email protected]> wrote:
> On RZ/G2L devices should be explicitly pulled out of reset for it
> to work. This patch adds support to read the "resets" property and
> performs deassert/assert when required.
>
> Also, propagate the error to the caller of sci_parse_dt() instead of
> returning NULL in case of failure.
>
> Signed-off-by: Lad Prabhakar <[email protected]>
> Reviewed-by: Biju Das <[email protected]>
Thanks for your patch!
> ---
> Hi Geert,
> For handling the resets I was in dual mind whether to perform
> reset based on compatible strings or soc-id, let me know your
> thoughts. Currently no SoC's use "renesas,sci" so using the same
> for performing the reset operation for SCI.
We do, on H8/300.
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -3203,23 +3204,58 @@ static const struct of_device_id of_sci_match[] = {
> };
> MODULE_DEVICE_TABLE(of, of_sci_match);
>
> +static void sci_reset_control_assert(void *data)
> +{
> + reset_control_assert(data);
> +}
> +
> static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
> unsigned int *dev_id)
> {
> struct device_node *np = pdev->dev.of_node;
> + const struct of_device_id *of_id;
> struct plat_sci_port *p;
> struct sci_port *sp;
> const void *data;
> int id;
>
> if (!IS_ENABLED(CONFIG_OF) || !np)
> - return NULL;
> + return ERR_PTR(-EINVAL);
> +
> + of_id = of_match_device(of_sci_match, &pdev->dev);
> + if (!of_id)
> + return ERR_PTR(-EINVAL);
>
> - data = of_device_get_match_data(&pdev->dev);
> + if (!strcmp(of_id->compatible, "renesas,scif-r9a07g044") ||
> + !strcmp(of_id->compatible, "renesas,sci")) {
This will match on H8/300, too, which doesn't have resets.
Please match against "renesas,sci-r9a07g044" instead.
Please don't use explicit strcmp() calls here, but add a flag to
of_sci_match[].data.
> + struct reset_control *rstc;
> + int ret;
> +
> + rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> + if (IS_ERR(rstc)) {
> + dev_err(&pdev->dev, "Error: missing reset ctrl\n");
> + return ERR_PTR(PTR_ERR(rstc));
> + }
> +
> + ret = reset_control_deassert(rstc);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to deassert %d\n", ret);
> + return ERR_PTR(ret);
> + }
> +
> + ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
> + ret);
> + return ERR_PTR(ret);
> + }
> + }
> +
> + data = of_id->data;
>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
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
Hi Geert,
Thank you for the review.
On Mon, Nov 8, 2021 at 4:40 PM Geert Uytterhoeven <[email protected]> wrote:
>
> Hi Prabhakar,
>
> On Wed, Nov 3, 2021 at 6:31 PM Lad Prabhakar
> <[email protected]> wrote:
> > On RZ/G2L devices should be explicitly pulled out of reset for it
> > to work. This patch adds support to read the "resets" property and
> > performs deassert/assert when required.
> >
> > Also, propagate the error to the caller of sci_parse_dt() instead of
> > returning NULL in case of failure.
> >
> > Signed-off-by: Lad Prabhakar <[email protected]>
> > Reviewed-by: Biju Das <[email protected]>
>
> Thanks for your patch!
>
> > ---
> > Hi Geert,
> > For handling the resets I was in dual mind whether to perform
> > reset based on compatible strings or soc-id, let me know your
> > thoughts. Currently no SoC's use "renesas,sci" so using the same
> > for performing the reset operation for SCI.
>
> We do, on H8/300.
>
Missed that.
> > --- a/drivers/tty/serial/sh-sci.c
> > +++ b/drivers/tty/serial/sh-sci.c
> > @@ -3203,23 +3204,58 @@ static const struct of_device_id of_sci_match[] = {
> > };
> > MODULE_DEVICE_TABLE(of, of_sci_match);
> >
> > +static void sci_reset_control_assert(void *data)
> > +{
> > + reset_control_assert(data);
> > +}
> > +
> > static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
> > unsigned int *dev_id)
> > {
> > struct device_node *np = pdev->dev.of_node;
> > + const struct of_device_id *of_id;
> > struct plat_sci_port *p;
> > struct sci_port *sp;
> > const void *data;
> > int id;
> >
> > if (!IS_ENABLED(CONFIG_OF) || !np)
> > - return NULL;
> > + return ERR_PTR(-EINVAL);
> > +
> > + of_id = of_match_device(of_sci_match, &pdev->dev);
> > + if (!of_id)
> > + return ERR_PTR(-EINVAL);
> >
> > - data = of_device_get_match_data(&pdev->dev);
> > + if (!strcmp(of_id->compatible, "renesas,scif-r9a07g044") ||
> > + !strcmp(of_id->compatible, "renesas,sci")) {
>
> This will match on H8/300, too, which doesn't have resets.
> Please match against "renesas,sci-r9a07g044" instead.
>
> Please don't use explicit strcmp() calls here, but add a flag to
> of_sci_match[].data.
>
Agreed, does the below hunk look good for handling the reset?
-#define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
+#define SCIx_RESET BIT(31)
+#define SCI_OF_DATA(type, regtype, reset) (void *)(reset |
(type) << 16 | (regtype))
#define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
#define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
@@ -3169,7 +3170,11 @@ static const struct of_device_id of_sci_match[] = {
},
{
.compatible = "renesas,scif-r9a07g044",
- .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
+ .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE,
SCIx_RESET),
+ },
+ {
+ .compatible = "renesas,sci-r9a07g044",
+ .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE, SCIx_RESET),
},
Cheers,
Prabhakar
> > + struct reset_control *rstc;
> > + int ret;
> > +
> > + rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> > + if (IS_ERR(rstc)) {
> > + dev_err(&pdev->dev, "Error: missing reset ctrl\n");
> > + return ERR_PTR(PTR_ERR(rstc));
> > + }
> > +
> > + ret = reset_control_deassert(rstc);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to deassert %d\n", ret);
> > + return ERR_PTR(ret);
> > + }
> > +
> > + ret = devm_add_action_or_reset(&pdev->dev, sci_reset_control_assert, rstc);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to register assert devm action, %d\n",
> > + ret);
> > + return ERR_PTR(ret);
> > + }
> > + }
> > +
> > + data = of_id->data;
> >
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
>
> 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
Hi Prabhakar,
On Tue, Nov 9, 2021 at 1:34 AM Lad, Prabhakar
<[email protected]> wrote:
> On Mon, Nov 8, 2021 at 4:40 PM Geert Uytterhoeven <[email protected]> wrote:
> > On Wed, Nov 3, 2021 at 6:31 PM Lad Prabhakar
> > <[email protected]> wrote:
> > > On RZ/G2L devices should be explicitly pulled out of reset for it
> > > to work. This patch adds support to read the "resets" property and
> > > performs deassert/assert when required.
> > >
> > > Also, propagate the error to the caller of sci_parse_dt() instead of
> > > returning NULL in case of failure.
> > >
> > > Signed-off-by: Lad Prabhakar <[email protected]>
> > > Reviewed-by: Biju Das <[email protected]>
> >
> > Thanks for your patch!
> >
> > > ---
> > > Hi Geert,
> > > For handling the resets I was in dual mind whether to perform
> > > reset based on compatible strings or soc-id, let me know your
> > > thoughts. Currently no SoC's use "renesas,sci" so using the same
> > > for performing the reset operation for SCI.
> >
> > We do, on H8/300.
> >
> Missed that.
>
> > > --- a/drivers/tty/serial/sh-sci.c
> > > +++ b/drivers/tty/serial/sh-sci.c
> > > @@ -3203,23 +3204,58 @@ static const struct of_device_id of_sci_match[] = {
> > > };
> > > MODULE_DEVICE_TABLE(of, of_sci_match);
> > >
> > > +static void sci_reset_control_assert(void *data)
> > > +{
> > > + reset_control_assert(data);
> > > +}
> > > +
> > > static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
> > > unsigned int *dev_id)
> > > {
> > > struct device_node *np = pdev->dev.of_node;
> > > + const struct of_device_id *of_id;
> > > struct plat_sci_port *p;
> > > struct sci_port *sp;
> > > const void *data;
> > > int id;
> > >
> > > if (!IS_ENABLED(CONFIG_OF) || !np)
> > > - return NULL;
> > > + return ERR_PTR(-EINVAL);
> > > +
> > > + of_id = of_match_device(of_sci_match, &pdev->dev);
> > > + if (!of_id)
> > > + return ERR_PTR(-EINVAL);
> > >
> > > - data = of_device_get_match_data(&pdev->dev);
> > > + if (!strcmp(of_id->compatible, "renesas,scif-r9a07g044") ||
> > > + !strcmp(of_id->compatible, "renesas,sci")) {
> >
> > This will match on H8/300, too, which doesn't have resets.
> > Please match against "renesas,sci-r9a07g044" instead.
> >
> > Please don't use explicit strcmp() calls here, but add a flag to
> > of_sci_match[].data.
> >
> Agreed, does the below hunk look good for handling the reset?
>
> -#define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
> +#define SCIx_RESET BIT(31)
> +#define SCI_OF_DATA(type, regtype, reset) (void *)(reset |
> (type) << 16 | (regtype))
> #define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
> #define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
>
> @@ -3169,7 +3170,11 @@ static const struct of_device_id of_sci_match[] = {
> },
> {
> .compatible = "renesas,scif-r9a07g044",
> - .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
> + .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE,
> SCIx_RESET),
> + },
> + {
> + .compatible = "renesas,sci-r9a07g044",
> + .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE, SCIx_RESET),
> },
That's what I had in mind.
But upon second thought, it might be better to just drop the check,
and obtain an optional reset instead?
After all the reset requirement is not a feature of this specific
SCI(F) variant, but an SoC integration feature. And deasserting
the reset on other SoCs that have a reset should be fine.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
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
Hi Geert,
On Tue, Nov 9, 2021 at 7:50 AM Geert Uytterhoeven <[email protected]> wrote:
>
> Hi Prabhakar,
>
> On Tue, Nov 9, 2021 at 1:34 AM Lad, Prabhakar
> <[email protected]> wrote:
> > On Mon, Nov 8, 2021 at 4:40 PM Geert Uytterhoeven <[email protected]> wrote:
> > > On Wed, Nov 3, 2021 at 6:31 PM Lad Prabhakar
> > > <[email protected]> wrote:
> > > > On RZ/G2L devices should be explicitly pulled out of reset for it
> > > > to work. This patch adds support to read the "resets" property and
> > > > performs deassert/assert when required.
> > > >
> > > > Also, propagate the error to the caller of sci_parse_dt() instead of
> > > > returning NULL in case of failure.
> > > >
> > > > Signed-off-by: Lad Prabhakar <[email protected]>
> > > > Reviewed-by: Biju Das <[email protected]>
> > >
> > > Thanks for your patch!
> > >
> > > > ---
> > > > Hi Geert,
> > > > For handling the resets I was in dual mind whether to perform
> > > > reset based on compatible strings or soc-id, let me know your
> > > > thoughts. Currently no SoC's use "renesas,sci" so using the same
> > > > for performing the reset operation for SCI.
> > >
> > > We do, on H8/300.
> > >
> > Missed that.
> >
> > > > --- a/drivers/tty/serial/sh-sci.c
> > > > +++ b/drivers/tty/serial/sh-sci.c
> > > > @@ -3203,23 +3204,58 @@ static const struct of_device_id of_sci_match[] = {
> > > > };
> > > > MODULE_DEVICE_TABLE(of, of_sci_match);
> > > >
> > > > +static void sci_reset_control_assert(void *data)
> > > > +{
> > > > + reset_control_assert(data);
> > > > +}
> > > > +
> > > > static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
> > > > unsigned int *dev_id)
> > > > {
> > > > struct device_node *np = pdev->dev.of_node;
> > > > + const struct of_device_id *of_id;
> > > > struct plat_sci_port *p;
> > > > struct sci_port *sp;
> > > > const void *data;
> > > > int id;
> > > >
> > > > if (!IS_ENABLED(CONFIG_OF) || !np)
> > > > - return NULL;
> > > > + return ERR_PTR(-EINVAL);
> > > > +
> > > > + of_id = of_match_device(of_sci_match, &pdev->dev);
> > > > + if (!of_id)
> > > > + return ERR_PTR(-EINVAL);
> > > >
> > > > - data = of_device_get_match_data(&pdev->dev);
> > > > + if (!strcmp(of_id->compatible, "renesas,scif-r9a07g044") ||
> > > > + !strcmp(of_id->compatible, "renesas,sci")) {
> > >
> > > This will match on H8/300, too, which doesn't have resets.
> > > Please match against "renesas,sci-r9a07g044" instead.
> > >
> > > Please don't use explicit strcmp() calls here, but add a flag to
> > > of_sci_match[].data.
> > >
> > Agreed, does the below hunk look good for handling the reset?
> >
> > -#define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype))
> > +#define SCIx_RESET BIT(31)
> > +#define SCI_OF_DATA(type, regtype, reset) (void *)(reset |
> > (type) << 16 | (regtype))
> > #define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16)
> > #define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff)
> >
> > @@ -3169,7 +3170,11 @@ static const struct of_device_id of_sci_match[] = {
> > },
> > {
> > .compatible = "renesas,scif-r9a07g044",
> > - .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
> > + .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE,
> > SCIx_RESET),
> > + },
> > + {
> > + .compatible = "renesas,sci-r9a07g044",
> > + .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE, SCIx_RESET),
> > },
>
> That's what I had in mind.
>
> But upon second thought, it might be better to just drop the check,
> and obtain an optional reset instead?
Agreed, will do that.
> After all the reset requirement is not a feature of this specific
> SCI(F) variant, but an SoC integration feature. And deasserting
> the reset on other SoCs that have a reset should be fine.
>
Indeed.
Cheers,
Prabhakar
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
>
> 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