* [PATCH 0/2] am335x: set pinmux registers from pins debug file @ 2021-05-16 13:55 Dario Binacchi 2021-05-16 13:55 ` [PATCH 2/2] pinctrl: single: set pinmux " Dario Binacchi 0 siblings, 1 reply; 3+ messages in thread From: Dario Binacchi @ 2021-05-16 13:55 UTC (permalink / raw) To: linux-kernel Cc: Dario Binacchi, Haojian Zhuang, Linus Walleij, Tony Lindgren, linux-arm-kernel, linux-gpio, linux-omap The patch was born from the need to change the slew rate of the LCD pins of a custom AM335x board during EMC tests. The AM335x, as described in a note in section 9.1 of its reference manual [1], is unable to write pinmux registers from user space. The series now makes it possible to write these registers from the pins debug file. [1] https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf Dario Binacchi (2): pinctrl: core: configure pinmux from pins debug file pinctrl: single: set pinmux from pins debug file drivers/pinctrl/core.c | 56 ++++++++++++++++++++++++++++++-- drivers/pinctrl/pinctrl-single.c | 20 ++++++++++++ include/linux/pinctrl/pinctrl.h | 2 ++ 3 files changed, 76 insertions(+), 2 deletions(-) -- 2.17.1 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 2/2] pinctrl: single: set pinmux from pins debug file 2021-05-16 13:55 [PATCH 0/2] am335x: set pinmux registers from pins debug file Dario Binacchi @ 2021-05-16 13:55 ` Dario Binacchi 2021-05-17 5:57 ` Tony Lindgren 0 siblings, 1 reply; 3+ messages in thread From: Dario Binacchi @ 2021-05-16 13:55 UTC (permalink / raw) To: linux-kernel Cc: Dario Binacchi, Haojian Zhuang, Linus Walleij, Tony Lindgren, linux-arm-kernel, linux-gpio, linux-omap 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> --- drivers/pinctrl/pinctrl-single.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c index 2c9c9835f375..cdbc2298360d 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) && IS_ENABLED(CONFIG_SOC_AM33XX) + .pin_dbg_set = pcs_pin_dbg_set, +#endif .dt_node_to_map = pcs_dt_node_to_map, .dt_free_map = pcs_dt_free_map, }; -- 2.17.1 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2] pinctrl: single: set pinmux from pins debug file 2021-05-16 13:55 ` [PATCH 2/2] pinctrl: single: set pinmux " Dario Binacchi @ 2021-05-17 5:57 ` Tony Lindgren 0 siblings, 0 replies; 3+ messages in thread From: Tony Lindgren @ 2021-05-17 5:57 UTC (permalink / raw) To: Dario Binacchi Cc: linux-kernel, Haojian Zhuang, Linus Walleij, linux-arm-kernel, linux-gpio, linux-omap Hi, * Dario Binacchi <dariobin@libero.it> [210516 13:55]: > @@ -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) && IS_ENABLED(CONFIG_SOC_AM33XX) > + .pin_dbg_set = pcs_pin_dbg_set, > +#endif > .dt_node_to_map = pcs_dt_node_to_map, > .dt_free_map = pcs_dt_free_map, > }; I don't think there should be any CONFIG_SOC_AM33XX dependency here? Regards, Tony ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-05-17 5:57 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-05-16 13:55 [PATCH 0/2] am335x: set pinmux registers from pins debug file Dario Binacchi 2021-05-16 13:55 ` [PATCH 2/2] pinctrl: single: set pinmux " Dario Binacchi 2021-05-17 5:57 ` Tony Lindgren
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