| Message ID | 1532685089-35645-2-git-send-email-biju.das@bp.renesas.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/4] gpio: rcar: Enhance gpio-ranges support | expand |
Hi Biju, On Fri, Jul 27, 2018 at 11:57 AM Biju Das <biju.das@bp.renesas.com> wrote: > Enhance gpio-ranges to support more than one gpio-range. > > Signed-off-by: Biju Das <biju.das@bp.renesas.com> > Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Thanks for your patch! However, I'm wondering if this works as intended, as the discontinuity is not in the pins, but in the GPIO bits. > --- > cat /sys/kernel/debug/pinctrl/e6060000.pin-controller-sh-pfc/gpio- > GPIO ranges handled: > 0: e6050000.gpio GPIOS [1001 - 1023] PINS [0 - 22] > 0: e6051000.gpio GPIOS [978 - 1000] PINS [32 - 54] > 0: e6052000.gpio GPIOS [946 - 977] PINS [64 - 95] > 0: e6053000.gpio GPIOS [926 - 942] PINS [96 - 112] > 17: e6053000.gpio GPIOS [943 - 945] PINS [123 - 125] The above two lines are the result of: + gpio-ranges = <&pfc 0 96 17>, <&pfc 17 123 3>; > 0: e6054000.gpio GPIOS [900 - 925] PINS [128 - 153] > 0: e6055000.gpio GPIOS [868 - 899] PINS [160 - 191] > --- > drivers/gpio/gpio-rcar.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c > index 350390c..a7bbe78 100644 > --- a/drivers/gpio/gpio-rcar.c > +++ b/drivers/gpio/gpio-rcar.c > @@ -399,13 +399,22 @@ static int gpio_rcar_parse_dt(struct gpio_rcar_priv *p, unsigned int *npins) > struct device_node *np = p->pdev->dev.of_node; > const struct gpio_rcar_info *info; > struct of_phandle_args args; > - int ret; > + int index = 0, ret; > > info = of_device_get_match_data(&p->pdev->dev); > > - ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, &args); > - *npins = ret == 0 ? args.args[2] : RCAR_MAX_GPIO_PER_BANK; > p->has_both_edge_trigger = info->has_both_edge_trigger; > + *npins = 0; > + for (;; index++) { > + ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, > + index, &args); > + if (ret) { > + if (index == 0) > + *npins = RCAR_MAX_GPIO_PER_BANK; > + break; > + } > + *npins += args.args[2]; > + } So after this, *npins will be the total number of GPIOs present in this bank (17 + 3 = 20), which will be used as gpio_chip.ngpio. All GPIO operations will use the passed offset as the bit number. gpio_rcar_resume() will resume bits 0..ngpio - 1 of each register. gpio_rcar_set_multiple() uses GENMASK(chip->ngpio - 1, 0) as the bank mask, and uses it to mask of bits in the registers. Hence all of the above assumes the register bits for the GPIOs are 0..19. However, according to the datasheet, the GPIOs in bank 3 are 0..16 and 27..29. So accessing GPIOs 17..19 in the bank will write to bits 17..19, not to 27..29! A simple way to work around this is to set ngpios to the highest bit number in use + 1. But you still need a mechanism to avoid accessing the unused bits in the gap between 16 and 27. > > if (*npins == 0 || *npins > RCAR_MAX_GPIO_PER_BANK) { > dev_warn(&p->pdev->dev, 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 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Geert, Thanks for the feedback. > -----Original Message----- > From: Geert Uytterhoeven [mailto:geert@linux-m68k.org] > Sent: 30 July 2018 11:04 > To: Biju Das <biju.das@bp.renesas.com> > Cc: Linus Walleij <linus.walleij@linaro.org>; open list:GPIO SUBSYSTEM > <linux-gpio@vger.kernel.org>; Simon Horman <horms@verge.net.au>; > Geert Uytterhoeven <geert+renesas@glider.be>; Chris Paterson > <Chris.Paterson2@renesas.com>; Fabrizio Castro > <fabrizio.castro@bp.renesas.com>; Linux-Renesas <linux-renesas- > soc@vger.kernel.org> > Subject: Re: [PATCH 1/4] gpio: rcar: Enhance gpio-ranges support > > Hi Biju, > > On Fri, Jul 27, 2018 at 11:57 AM Biju Das <biju.das@bp.renesas.com> wrote: > > Enhance gpio-ranges to support more than one gpio-range. > > > > Signed-off-by: Biju Das <biju.das@bp.renesas.com> > > Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> > > Thanks for your patch! > > However, I'm wondering if this works as intended, as the discontinuity is not > in the pins, but in the GPIO bits. > > > --- > > cat /sys/kernel/debug/pinctrl/e6060000.pin-controller-sh-pfc/gpio- > > GPIO ranges handled: > > 0: e6050000.gpio GPIOS [1001 - 1023] PINS [0 - 22] > > 0: e6051000.gpio GPIOS [978 - 1000] PINS [32 - 54] > > 0: e6052000.gpio GPIOS [946 - 977] PINS [64 - 95] > > 0: e6053000.gpio GPIOS [926 - 942] PINS [96 - 112] > > 17: e6053000.gpio GPIOS [943 - 945] PINS [123 - 125] > > The above two lines are the result of: > > + gpio-ranges = <&pfc 0 96 17>, <&pfc 17 123 3>; > > > 0: e6054000.gpio GPIOS [900 - 925] PINS [128 - 153] > > 0: e6055000.gpio GPIOS [868 - 899] PINS [160 - 191] > > --- > > drivers/gpio/gpio-rcar.c | 15 ++++++++++++--- > > 1 file changed, 12 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c index > > 350390c..a7bbe78 100644 > > --- a/drivers/gpio/gpio-rcar.c > > +++ b/drivers/gpio/gpio-rcar.c > > @@ -399,13 +399,22 @@ static int gpio_rcar_parse_dt(struct > gpio_rcar_priv *p, unsigned int *npins) > > struct device_node *np = p->pdev->dev.of_node; > > const struct gpio_rcar_info *info; > > struct of_phandle_args args; > > - int ret; > > + int index = 0, ret; > > > > info = of_device_get_match_data(&p->pdev->dev); > > > > - ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, > &args); > > - *npins = ret == 0 ? args.args[2] : RCAR_MAX_GPIO_PER_BANK; > > p->has_both_edge_trigger = info->has_both_edge_trigger; > > + *npins = 0; > > + for (;; index++) { > > + ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, > > + index, &args); > > + if (ret) { > > + if (index == 0) > > + *npins = RCAR_MAX_GPIO_PER_BANK; > > + break; > > + } > > + *npins += args.args[2]; > > + } > > So after this, *npins will be the total number of GPIOs present in this bank > (17 + 3 = 20), which will be used as gpio_chip.ngpio. > > All GPIO operations will use the passed offset as the bit number. > gpio_rcar_resume() will resume bits 0..ngpio - 1 of each register. > gpio_rcar_set_multiple() uses GENMASK(chip->ngpio - 1, 0) as the bank > mask, and uses it to mask of bits in the registers. > > Hence all of the above assumes the register bits for the GPIOs are 0..19. > However, according to the datasheet, the GPIOs in bank 3 are 0..16 and > 27..29. So accessing GPIOs 17..19 in the bank will write to bits 17..19, not to > 27..29! I have done the below GPIO operation using sysfs to check this. (As per this gpio 943 mapped to gpiobit 17 which request Pin123(GP3_27) But I haven't checked GPIO registers to check whether it is actually setting the values to GP3_17 or GP3_27. Will check this. root@iwg23s:~# echo 943 > /sys/class/gpio/export [ 51.796570] sh-pfc e6060000.pin-controller: request pin 123 (GP_3_27) for e6053000.gpio:943 [ 51.804960] sh-pfc e6060000.pin-controller: write_reg addr = e6060010, value = 0x0, field = 4, r_width = 32, f_width = 1 Kernel logs:- ---------------- [ 0.110156] gpio gpiochip3: (e6053000.gpio): created GPIO range 0->16 ==> e6060000.pin-controller PIN 96->112 [ 0.110187] gpio gpiochip3: (e6053000.gpio): created GPIO range 17->19 ==> e6060000.pin-controller PIN 123->125 [ 0.110363] gpio gpiochip3: (e6053000.gpio): added GPIO chardev (254:3) [ 0.110460] gpiochip_setup_dev: registered GPIOs 926 to 945 on device: gpiochip3 (e6053000.gpio) PIncontrol related for GPIO 3 ---------------------------------------- pin 96 (GP_3_0): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 97 (GP_3_1): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 98 (GP_3_2): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 99 (GP_3_3): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 100 (GP_3_4): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 101 (GP_3_5): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 102 (GP_3_6): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 103 (GP_3_7): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 104 (GP_3_8): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 105 (GP_3_9): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 106 (GP_3_10): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 107 (GP_3_11): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 108 (GP_3_12): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 109 (GP_3_13): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 110 (GP_3_14): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 111 (GP_3_15): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 112 (GP_3_16): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 123 (GP_3_27): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 124 (GP_3_28): (MUX UNCLAIMED) (GPIO UNCLAIMED) pin 125 (GP_3_29): (MUX UNCLAIMED) (GPIO UNCLAIMED) range seen by pin control driver ------------------------------------------- cat /sys/kernel/debug/pinctrl/e6060000.pin-controller-sh-pfc/gpio-ranges 0: e6050000.gpio GPIOS [1001 - 1023] PINS [0 - 22] 0: e6051000.gpio GPIOS [978 - 1000] PINS [32 - 54] 0: e6052000.gpio GPIOS [946 - 977] PINS [64 - 95] 0: e6053000.gpio GPIOS [926 - 942] PINS [96 - 112] 17: e6053000.gpio GPIOS [943 - 945] PINS [123 - 125]-- > New gpio range mapping pin 123-125 0: e6054000.gpio GPIOS [900 - 925] PINS [128 - 153] 0: e6055000.gpio GPIOS [868 - 899] PINS [160 - 191] range seen by gpio driver ----------------------------- [ 0.105883] gpio_rcar e6050000.gpio: driving 23 GPIOs [ 0.106328] gpio_rcar e6051000.gpio: driving 23 GPIOs [ 0.106682] gpio_rcar e6052000.gpio: driving 32 GPIOs [ 0.107028] gpio_rcar e6053000.gpio: driving 20 GPIOs [ 0.107388] gpio_rcar e6054000.gpio: driving 26 GPIOs [ 0.107718] gpio_rcar e6055000.gpio: driving 32 GPIOs Regards, Biju > A simple way to work around this is to set ngpios to the highest bit number in > use + 1. But you still need a mechanism to avoid accessing the unused bits in > the gap between 16 and 27. > > > > if (*npins == 0 || *npins > RCAR_MAX_GPIO_PER_BANK) { > > dev_warn(&p->pdev->dev, > > 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 Renesas Electronics Europe Ltd, Dukes Meadow, Millboard Road, Bourne End, Buckinghamshire, SL8 5FH, UK. Registered in England & Wales under Registered No. 04586709.
Hi Geert, > Subject: Re: [PATCH 1/4] gpio: rcar: Enhance gpio-ranges support > A simple way to work around this is to set ngpios to the highest bit number in > use + 1. But you still need a mechanism to avoid accessing the unused bits in > the gap between 16 and 27. > I will send V2 with following changes 1) Dt binding related to changes for adding optional property " gpio-reserved-ranges" on renesas binding documentation 2) SoC Dtsi with " gpio-ranges = <&pfc 0 96 30>" 3) SoC Dtsi with" gpio-reserved-ranges = <17 10>" which defines unused gpios 4) Handle unused gpios in a) gpio_rcar_request b) gpio_rcar_set_multiple c) gpio_rcar_resume Regards, Biju Renesas Electronics Europe Ltd, Dukes Meadow, Millboard Road, Bourne End, Buckinghamshire, SL8 5FH, UK. Registered in England & Wales under Registered No. 04586709.
diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c index 350390c..a7bbe78 100644 --- a/drivers/gpio/gpio-rcar.c +++ b/drivers/gpio/gpio-rcar.c @@ -399,13 +399,22 @@ static int gpio_rcar_parse_dt(struct gpio_rcar_priv *p, unsigned int *npins) struct device_node *np = p->pdev->dev.of_node; const struct gpio_rcar_info *info; struct of_phandle_args args; - int ret; + int index = 0, ret; info = of_device_get_match_data(&p->pdev->dev); - ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, &args); - *npins = ret == 0 ? args.args[2] : RCAR_MAX_GPIO_PER_BANK; p->has_both_edge_trigger = info->has_both_edge_trigger; + *npins = 0; + for (;; index++) { + ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, + index, &args); + if (ret) { + if (index == 0) + *npins = RCAR_MAX_GPIO_PER_BANK; + break; + } + *npins += args.args[2]; + } if (*npins == 0 || *npins > RCAR_MAX_GPIO_PER_BANK) { dev_warn(&p->pdev->dev,