| Message ID | 20210517200002.6316-3-dariobin@libero.it (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | am335x: set pinmux registers from pins debug file | expand |
Hi, I noticed few more things I started to wonder about after looking at this again. * Dario Binacchi <dariobin@libero.it> [210517 20:00]: > +static int pcs_pin_dbg_set(struct pinctrl_dev *pctldev, unsigned int pin, > + char *buf) > +{ > + struct pcs_device *pcs; > + unsigned int val, mux_bytes; > + > + buf = skip_spaces(buf); > + if (kstrtouint(buf, 0, &val)) > + return -EINVAL; > + > + pcs = pinctrl_dev_get_drvdata(pctldev); > + > + mux_bytes = pcs->width / BITS_PER_BYTE; > + pcs->write(val, pcs->base + pin * mux_bytes); > + return 0; > +} Since you're adding a new interface, how about pass unsigned int val instead of char *buf? > static void pcs_dt_free_map(struct pinctrl_dev *pctldev, > struct pinctrl_map *map, unsigned num_maps) > { > @@ -331,6 +348,9 @@ static const struct pinctrl_ops pcs_pinctrl_ops = { > .get_group_name = pinctrl_generic_get_group_name, > .get_group_pins = pinctrl_generic_get_group_pins, > .pin_dbg_show = pcs_pin_dbg_show, > +#if IS_ENABLED(CONFIG_DEVMEM) > + .pin_dbg_set = pcs_pin_dbg_set, > +#endif > .dt_node_to_map = pcs_dt_node_to_map, > .dt_free_map = pcs_dt_free_map, > }; It might be better to always have the .pin_dbg_set around to avoid the IS_ENABLED(CONFIG_DEVMEM). Does the new interface need something under Documentation too? Regards, Tony
Hi Tony, > Il 18/05/2021 08:05 Tony Lindgren <tony@atomide.com> ha scritto: > > > Hi, > > I noticed few more things I started to wonder about after > looking at this again. > > * Dario Binacchi <dariobin@libero.it> [210517 20:00]: > > +static int pcs_pin_dbg_set(struct pinctrl_dev *pctldev, unsigned int pin, > > + char *buf) > > +{ > > + struct pcs_device *pcs; > > + unsigned int val, mux_bytes; > > + > > + buf = skip_spaces(buf); > > + if (kstrtouint(buf, 0, &val)) > > + return -EINVAL; > > + > > + pcs = pinctrl_dev_get_drvdata(pctldev); > > + > > + mux_bytes = pcs->width / BITS_PER_BYTE; > > + pcs->write(val, pcs->base + pin * mux_bytes); > > + return 0; > > +} > > Since you're adding a new interface, how about pass unsigned > int val instead of char *buf? I thought about passing char *buf because it seemed more generic to me. As the output of pin_dbg_show() depends on the platform driver, perhaps pin_dbg_set() may need driver-dependent data. Is it possible that only the value to be set in the register (unsigned int) is required? > > > static void pcs_dt_free_map(struct pinctrl_dev *pctldev, > > struct pinctrl_map *map, unsigned num_maps) > > { > > @@ -331,6 +348,9 @@ static const struct pinctrl_ops pcs_pinctrl_ops = { > > .get_group_name = pinctrl_generic_get_group_name, > > .get_group_pins = pinctrl_generic_get_group_pins, > > .pin_dbg_show = pcs_pin_dbg_show, > > +#if IS_ENABLED(CONFIG_DEVMEM) > > + .pin_dbg_set = pcs_pin_dbg_set, > > +#endif > > .dt_node_to_map = pcs_dt_node_to_map, > > .dt_free_map = pcs_dt_free_map, > > }; > > It might be better to always have the .pin_dbg_set around to > avoid the IS_ENABLED(CONFIG_DEVMEM). Ok, I'll remove the CONFIG_DEVMEM dependency > > Does the new interface need something under Documentation too? Yes, the description of `pins` in Documentation/driver-api/pin-control.rst needs to be updated. I'll add another patch to the series. Thanks and regards, Dario > > Regards, > > Tony
* Dario Binacchi <dariobin@libero.it> [210518 08:57]: > I thought about passing char *buf because it seemed more generic > to me. As the output of pin_dbg_show() depends on the platform > driver, perhaps pin_dbg_set() may need driver-dependent data. > Is it possible that only the value to be set in the register > (unsigned int) is required? Maybe Linus W can answer this one. Regards, Tony
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c index 2c9c9835f375..8497414e3384 100644 --- a/drivers/pinctrl/pinctrl-single.c +++ b/drivers/pinctrl/pinctrl-single.c @@ -313,6 +313,23 @@ static void pcs_pin_dbg_show(struct pinctrl_dev *pctldev, seq_printf(s, "%zx %08x %s ", pa, val, DRIVER_NAME); } +static int pcs_pin_dbg_set(struct pinctrl_dev *pctldev, unsigned int pin, + char *buf) +{ + struct pcs_device *pcs; + unsigned int val, mux_bytes; + + buf = skip_spaces(buf); + if (kstrtouint(buf, 0, &val)) + return -EINVAL; + + pcs = pinctrl_dev_get_drvdata(pctldev); + + mux_bytes = pcs->width / BITS_PER_BYTE; + pcs->write(val, pcs->base + pin * mux_bytes); + return 0; +} + static void pcs_dt_free_map(struct pinctrl_dev *pctldev, struct pinctrl_map *map, unsigned num_maps) { @@ -331,6 +348,9 @@ static const struct pinctrl_ops pcs_pinctrl_ops = { .get_group_name = pinctrl_generic_get_group_name, .get_group_pins = pinctrl_generic_get_group_pins, .pin_dbg_show = pcs_pin_dbg_show, +#if IS_ENABLED(CONFIG_DEVMEM) + .pin_dbg_set = pcs_pin_dbg_set, +#endif .dt_node_to_map = pcs_dt_node_to_map, .dt_free_map = pcs_dt_free_map, };
As described in section 9.1 of the TI reference manual for AM335x [1], "For writing to the control module registers, the MPU will need to be in privileged mode of operation and writes will not work from user mode". By adding the pin_dbg_set helper to pcs_pinctrl_ops it will be possible to write these registers from the pins debug: cd /sys/kernel/debug/pinctrl/44e10800.pinmux-pinctrl-single/ echo <pin-number> <reg-value> >pins [1] https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf Signed-off-by: Dario Binacchi <dariobin@libero.it> --- Changes in v2: - Remove CONFIG_SOC_AM33XX dependency. drivers/pinctrl/pinctrl-single.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)