[PATCH 2/5] gpio: qcom_pmic: rework pwrkey driver into a button driver
Stephan Gerhold
stephan at gerhold.net
Tue Nov 7 14:27:44 CET 2023
On Mon, Nov 06, 2023 at 08:57:30PM +0000, Caleb Connolly wrote:
> The power and resin keys were implemented as GPIOs here, but their only
> use would be as buttons. Avoid the additional layer of introspection and
> rework this driver into a button driver.
>
> While we're here, replace the "qcom,pm8998-pwrkey" compatible with
> "qcom,pm8941-pwrkey" to match upstream (Linux).
>
> The dragonboard410c and 820c boards are adjusted to benefit from this
> change too, simplify their custom board init code.
>
> Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
Thanks a lot for working on bringing the Qualcomm DTs in U-Boot closer
to Linux upstream! I agree that modelling the pwr/resin keys is better
than exposing tham as GPIOs.
I'm a bit confused about the actual diff in this patch series though.
Did you perhaps forget to make some changes you had planned or sent the
wrong version?
In particular:
- You talk about replacing the custom "qcom,pm8998-pwrkey" compatible
with "qcom,pm8941-pwrkey" to match upstream, but don't seem to adjust
the users (sdm845.dtsi)?
- sdm845.dtsi also uses GPIOs for PON, but you only update DB410c and
DB820c. Isn't SDM845 the platform you're testing on?
Some more comments below.
> ---
> arch/arm/dts/dragonboard410c-uboot.dtsi | 11 +-
> arch/arm/dts/dragonboard820c-uboot.dtsi | 9 +-
> arch/arm/dts/dragonboard820c.dts | 3 -
> board/qualcomm/dragonboard410c/dragonboard410c.c | 29 ++--
> board/qualcomm/dragonboard820c/dragonboard820c.c | 29 ++--
> drivers/gpio/Kconfig | 3 +-
> drivers/gpio/qcom_pmic_gpio.c | 161 +++++++++++++++--------
> 7 files changed, 139 insertions(+), 106 deletions(-)
>
> diff --git a/arch/arm/dts/dragonboard410c-uboot.dtsi b/arch/arm/dts/dragonboard410c-uboot.dtsi
> index 3b0bd0ed0a1b..c96f1fcc8930 100644
> --- a/arch/arm/dts/dragonboard410c-uboot.dtsi
> +++ b/arch/arm/dts/dragonboard410c-uboot.dtsi
> @@ -5,6 +5,9 @@
> * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski at gmail.com>
> */
>
> +#include <dt-bindings/input/linux-event-codes.h>
> +#include <dt-bindings/interrupt-controller/irq.h>
> +
> / {
>
> smem {
> @@ -46,10 +49,14 @@
>
> &pm8916_pon {
> key_vol_down {
> - gpios = <&pm8916_pon 1 0>;
> + interrupts = <0x0 0x8 1 IRQ_TYPE_EDGE_BOTH>;
> + linux,code = <KEY_DOWN>;
> + label = "key_vol_down";
> };
>
> key_power {
> - gpios = <&pm8916_pon 0 0>;
> + interrupts = <0x0 0x8 0 IRQ_TYPE_EDGE_BOTH>;
> + linux,code = <KEY_ENTER>;
> + label = "key_power";
> };
> };
The upstream Linux DT looks like this:
pon at 800 {
compatible = "qcom,pm8916-pon";
reg = <0x800>;
mode-bootloader = <0x2>;
mode-recovery = <0x1>;
pwrkey {
compatible = "qcom,pm8941-pwrkey";
interrupts = <0x0 0x8 0 IRQ_TYPE_EDGE_BOTH>;
debounce = <15625>;
bias-pull-up;
linux,code = <KEY_POWER>;
};
pm8916_resin: resin {
compatible = "qcom,pm8941-resin";
interrupts = <0x0 0x8 1 IRQ_TYPE_EDGE_BOTH>;
debounce = <15625>;
bias-pull-up;
linux,code = <KEY_VOLUME_DOWN>;
};
};
The new version you add is closer to upstream, but you also add a new
custom property called "label". You could just derive a unique label
from the node name ("pwrkey" vs "resin").
For looking up the buttons in the DB410c/DB820c couldn't you just loop
over all buttons and find a suitable one based on button_get_code()?
I think having different *linux*,code values (KEY_POWER vs KEY_ENTER and
KEY_DOWN vs KEY_VOLUME_DOWN) is also a bit strange. If U-Boot wants
different key codes it's kind of not the Linux code anymore, might as
well call it "u-boot,code" then. :-)
If KEY_POWER => KEY_ENTER and KEY_VOLUME_DOWN => KEY_DOWN is more useful
for U-Boot maybe that mapping could be done automatically in the code,
without having to change the real hardware description in the DT.
> diff --git a/arch/arm/dts/dragonboard820c.dts b/arch/arm/dts/dragonboard820c.dts
> index ad201d48749c..7db0cc9d64cc 100644
> --- a/arch/arm/dts/dragonboard820c.dts
> +++ b/arch/arm/dts/dragonboard820c.dts
> @@ -112,9 +112,6 @@
> pm8994_pon: pm8994_pon at 800 {
> compatible = "qcom,pm8994-pwrkey";
> reg = <0x800 0x96>;
> - #gpio-cells = <2>;
> - gpio-controller;
> - gpio-bank-name="pm8994_key.";
> };
Shouldn't we do the same change for pm8916_pon in db410c.dts?
> diff --git a/drivers/gpio/qcom_pmic_gpio.c b/drivers/gpio/qcom_pmic_gpio.c
> index e5841f502953..3dbc02d83198 100644
> --- a/drivers/gpio/qcom_pmic_gpio.c
> +++ b/drivers/gpio/qcom_pmic_gpio.c
> @@ -5,8 +5,10 @@
> * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski at gmail.com>
> */
>
> +#include <button.h>
> #include <common.h>
> #include <dm.h>
> +#include <dm/lists.h>
> #include <log.h>
> #include <power/pmic.h>
> #include <spmi/spmi.h>
> @@ -275,107 +277,150 @@ U_BOOT_DRIVER(qcom_pmic_gpio) = {
> .priv_auto = sizeof(struct qcom_gpio_bank),
> };
>
> +struct qcom_pmic_btn_priv {
> + u32 base;
> + u32 status_bit;
> + int code;
> + struct udevice *pmic;
> +};
>
> /* Add pmic buttons as GPIO as well - there is no generic way for now */
> #define PON_INT_RT_STS 0x10
> #define KPDPWR_ON_INT_BIT 0
> #define RESIN_ON_INT_BIT 1
>
> -static int qcom_pwrkey_get_function(struct udevice *dev, unsigned offset)
> +static enum button_state_t qcom_pwrkey_get_state(struct udevice *dev)
> {
> - return GPIOF_INPUT;
> -}
> + struct qcom_pmic_btn_priv *priv = dev_get_priv(dev);
>
> -static int qcom_pwrkey_get_value(struct udevice *dev, unsigned offset)
> -{
> - struct qcom_gpio_bank *priv = dev_get_priv(dev);
> -
> - int reg = pmic_reg_read(dev->parent, priv->pid + PON_INT_RT_STS);
> + int reg = pmic_reg_read(priv->pmic, priv->base + PON_INT_RT_STS);
>
> if (reg < 0)
> return 0;
>
> - switch (offset) {
> - case 0: /* Power button */
> - return (reg & BIT(KPDPWR_ON_INT_BIT)) != 0;
> - break;
> - case 1: /* Reset button */
> - default:
> - return (reg & BIT(RESIN_ON_INT_BIT)) != 0;
> - break;
> - }
> + return (reg & BIT(priv->status_bit)) != 0;
> }
>
> -/*
> - * Since pmic buttons modelled as GPIO, we need empty direction functions
> - * to trick u-boot button driver
> - */
> -static int qcom_pwrkey_direction_input(struct udevice *dev, unsigned int offset)
> +static int qcom_pwrkey_get_code(struct udevice *dev)
> {
> - return 0;
> -}
> + struct qcom_pmic_btn_priv *priv = dev_get_priv(dev);
>
> -static int qcom_pwrkey_direction_output(struct udevice *dev, unsigned int offset, int value)
> -{
> - return -EOPNOTSUPP;
> + return priv->code;
> }
>
> -static const struct dm_gpio_ops qcom_pwrkey_ops = {
> - .get_value = qcom_pwrkey_get_value,
> - .get_function = qcom_pwrkey_get_function,
> - .direction_input = qcom_pwrkey_direction_input,
> - .direction_output = qcom_pwrkey_direction_output,
> -};
> -
> static int qcom_pwrkey_probe(struct udevice *dev)
> {
> - struct qcom_gpio_bank *priv = dev_get_priv(dev);
> - int reg;
> - u64 pid;
> + struct button_uc_plat *uc_plat = dev_get_uclass_plat(dev);
> + struct qcom_pmic_btn_priv *priv = dev_get_priv(dev);
> + int ret;
> + u64 base;
>
> - pid = dev_read_addr(dev);
> - if (pid == FDT_ADDR_T_NONE)
> - return log_msg_ret("bad address", -EINVAL);
> + /* Ignore the top-level button node */
> + if (!uc_plat->label)
> + return 0;
>
> - priv->pid = pid;
> + /* the pwrkey and resin nodes are children of the "pon" node, get the
> + * PMIC device to use in pmic_reg_* calls.
> + */
> + priv->pmic = dev->parent->parent;
> +
> + base = dev_read_addr(dev);
> + if (!base || base == FDT_ADDR_T_NONE) {
> + /* Linux devicetrees don't specify an address in the pwrkey node */
> + base = dev_read_addr(dev->parent);
> + if (base == FDT_ADDR_T_NONE) {
> + printf("%s: Can't find address\n", dev->name);
> + return -EINVAL;
> + }
> + }
Is it worth introducing new code that supports non-standard Linux DTs?
Or do we need to stay compatible with old U-Boot DTs too? Would expect
those are always bundled together with U-Boot.
> +
> + priv->base = base;
>
> /* Do a sanity check */
> - reg = pmic_reg_read(dev->parent, priv->pid + REG_TYPE);
> - if (reg != 0x1)
> - return log_msg_ret("bad type", -ENXIO);
> + ret = pmic_reg_read(priv->pmic, priv->base + REG_TYPE);
> + if (ret != 0x1 && ret != 0xb) {
> + printf("%s: unexpected PMIC function type %d\n", dev->name, ret);
> + return -ENXIO;
> + }
>
> - reg = pmic_reg_read(dev->parent, priv->pid + REG_SUBTYPE);
> - if ((reg & 0x5) == 0)
> - return log_msg_ret("bad subtype", -ENXIO);
> + ret = pmic_reg_read(priv->pmic, priv->base + REG_SUBTYPE);
> + if ((ret & 0x7) == 0) {
> + printf("%s: unexpected PMCI function subtype %d\n", dev->name, ret);
> + //return -ENXIO;
I guess this shouldn't be commented out? :D
> + }
> +
> + /* Bit of a hack, we use the interrupt number to derive if this is the pwrkey or resin
> + * node, it just so happens to line up with the bit numbers in the interrupt status register
> + */
> + ret = ofnode_read_u32_index(dev_ofnode(dev), "interrupts", 2, &priv->status_bit);
> + if (ret < 0) {
> + printf("%s: Couldn't read interrupts: %d\n", __func__, ret);
> + return ret;
> + }
> +
> + ret = ofnode_read_u32(dev_ofnode(dev), "linux,code", &priv->code);
> + if (ret < 0) {
> + printf("%s: Couldn't read interrupts: %d\n", __func__, ret);
> + return ret;
> + }
>
> return 0;
> }
>
> -static int qcom_pwrkey_of_to_plat(struct udevice *dev)
> +static int button_qcom_pmic_bind(struct udevice *parent)
> {
> - struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
> + struct udevice *dev;
> + ofnode node;
> + int ret;
>
> - uc_priv->gpio_count = 2;
> - uc_priv->bank_name = dev_read_string(dev, "gpio-bank-name");
> - if (uc_priv->bank_name == NULL)
> - uc_priv->bank_name = "pwkey_qcom";
> + dev_for_each_subnode(node, parent) {
> + struct button_uc_plat *uc_plat;
> + const char *label;
> +
> + if (!ofnode_is_enabled(node))
> + continue;
> +
> + label = ofnode_read_string(node, "label");
> + if (!label) {
> + printf("%s: node %s has no label\n", __func__,
> + ofnode_get_name(node));
> + /* Don't break booting, just print a warning and continue */
> + continue;
> + }
> + /* We need the PMIC device to be the parent, so flatten it out here */
> + ret = device_bind_driver_to_node(parent, "pwrkey_qcom",
> + ofnode_get_name(node),
> + node, &dev);
> + if (ret) {
> + printf("Failed to bind %s! %d\n", label, ret);
> + return ret;
> + }
> + uc_plat = dev_get_uclass_plat(dev);
> + uc_plat->label = label;
> + }
>
> return 0;
> }
>
> +static const struct button_ops button_qcom_pmic_ops = {
> + .get_state = qcom_pwrkey_get_state,
> + .get_code = qcom_pwrkey_get_code,
> +};
> +
> static const struct udevice_id qcom_pwrkey_ids[] = {
> { .compatible = "qcom,pm8916-pwrkey" },
> { .compatible = "qcom,pm8994-pwrkey" },
These are also qcom,pm8941-pwrkey upstream.
> - { .compatible = "qcom,pm8998-pwrkey" },
> + { .compatible = "qcom,pm8941-pwrkey" },
> + { .compatible = "qcom,pm8998-pon" },
"qcom,pm8998-pon" is the outer container node for pwrkey+resin, while
"qcom,pm8941-pwrkey" is the actual power button. Why are both here next
to each other?
> { }
> };
>
> U_BOOT_DRIVER(pwrkey_qcom) = {
> .name = "pwrkey_qcom",
> - .id = UCLASS_GPIO,
> + .id = UCLASS_BUTTON,
> .of_match = qcom_pwrkey_ids,
> - .of_to_plat = qcom_pwrkey_of_to_plat,
> + .bind = button_qcom_pmic_bind,
> .probe = qcom_pwrkey_probe,
> - .ops = &qcom_pwrkey_ops,
> - .priv_auto = sizeof(struct qcom_gpio_bank),
> + .ops = &button_qcom_pmic_ops,
> + .priv_auto = sizeof(struct qcom_pmic_btn_priv),
> };
>
Can we move this out of the drivers/gpio into drivers/button? Seems like
there are now two quite different drivers in the same file. :-)
Thanks,
Stephan
More information about the U-Boot
mailing list