[RFC PATCH 10/15] pwrseq: add support for QCA BT+WiFi power sequencer

[Dmitry Baryshkov]

Hi,

On Fri, 20 Aug 2021 at 02:17, Bjorn Andersson
<bjorn.andersson at linaro.org> wrote:
>
> On Mon 16 Aug 17:55 PDT 2021, Dmitry Baryshkov wrote:
> [..]
> > diff --git a/drivers/power/pwrseq/pwrseq_qca.c b/drivers/power/pwrseq/pwrseq_qca.c
> > new file mode 100644
> > index 000000000000..3421a4821126
> > --- /dev/null
> > +++ b/drivers/power/pwrseq/pwrseq_qca.c
> > @@ -0,0 +1,290 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2021, Linaro Ltd.
> > + *
> > + * Author: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> > + *
> > + * Power Sequencer for Qualcomm WiFi + BT SoCs
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pwrseq/driver.h>
> > +#include <linux/regulator/consumer.h>
> > +
> > +/*
> > + * Voltage regulator information required for configuring the
> > + * QCA WiFi+Bluetooth chipset
> > + */
> > +struct qca_vreg {
> > +     const char *name;
> > +     unsigned int load_uA;
> > +};
> > +
> > +struct qca_device_data {
> > +     struct qca_vreg vddio;
>
> Any particular reason why this isn't just the first entry in vregs and
> operated as part of the bulk API?

Because VDDIO should be up before bringing the rest of the power
sources (at least for wcn39xx). This is usually the case since VDDIO
is S4A, but I'd still prefer to express this in the code.
And register_bulk_enable powers up all the supplies asynchronously,
thus it can not guarantee that the first entry would be powered up
first.

>
> > +     struct qca_vreg *vregs;
> > +     size_t num_vregs;
> > +     bool has_bt_en;
> > +     bool has_wifi_en;
> > +};
> > +
> > +struct pwrseq_qca;
> > +struct pwrseq_qca_one {
> > +     struct pwrseq_qca *common;
> > +     struct gpio_desc *enable;
> > +};
> > +
> > +#define PWRSEQ_QCA_WIFI 0
> > +#define PWRSEQ_QCA_BT 1
> > +
> > +#define PWRSEQ_QCA_MAX 2
> > +
> > +struct pwrseq_qca {
> > +     struct regulator *vddio;
> > +     struct gpio_desc *sw_ctrl;
> > +     struct pwrseq_qca_one pwrseq_qcas[PWRSEQ_QCA_MAX];
> > +     int num_vregs;
> > +     struct regulator_bulk_data vregs[];
> > +};
> > +
> > +static int pwrseq_qca_power_on(struct pwrseq *pwrseq)
> > +{
> > +     struct pwrseq_qca_one *qca_one = pwrseq_get_data(pwrseq);
> > +     int ret;
> > +
> > +     if (qca_one->common->vddio) {
>
> devm_regulator_get() doesn't return NULL, so this is always true.

This is more of the safety guard for the cases when the qca doesn't
have the special vddio supply.

>
> > +             ret = regulator_enable(qca_one->common->vddio);
> > +             if (ret)
> > +                     return ret;
> > +     }
> > +
> > +     ret = regulator_bulk_enable(qca_one->common->num_vregs, qca_one->common->vregs);
> > +     if (ret)
> > +             goto vddio_off;
> > +
> > +     if (qca_one->enable) {
> > +             gpiod_set_value_cansleep(qca_one->enable, 0);
> > +             msleep(50);
> > +             gpiod_set_value_cansleep(qca_one->enable, 1);
> > +             msleep(150);
> > +     }
> > +
> > +     if (qca_one->common->sw_ctrl) {
> > +             bool sw_ctrl_state = gpiod_get_value_cansleep(qca_one->common->sw_ctrl);
> > +             dev_dbg(&pwrseq->dev, "SW_CTRL is %d", sw_ctrl_state);
> > +     }
> > +
> > +     return 0;
> > +
> > +vddio_off:
> > +     regulator_disable(qca_one->common->vddio);
> > +
> > +     return ret;
> > +}
> [..]
> > +static int pwrseq_qca_probe(struct platform_device *pdev)
> > +{
> > +     struct pwrseq_qca *pwrseq_qca;
> > +     struct pwrseq *pwrseq;
> > +     struct pwrseq_provider *provider;
> > +     struct device *dev = &pdev->dev;
> > +     struct pwrseq_onecell_data *onecell;
> > +     const struct qca_device_data *data;
> > +     int ret, i;
> > +
> > +     data = device_get_match_data(dev);
> > +     if (!data)
> > +             return -EINVAL;
> > +
> > +     pwrseq_qca = devm_kzalloc(dev, struct_size(pwrseq_qca, vregs, data->num_vregs), GFP_KERNEL);
> > +     if (!pwrseq_qca)
> > +             return -ENOMEM;
> > +
> > +     onecell = devm_kzalloc(dev, struct_size(onecell, pwrseqs, PWRSEQ_QCA_MAX), GFP_KERNEL);
> > +     if (!onecell)
> > +             return -ENOMEM;
> > +
> > +     ret = pwrseq_qca_regulators_init(dev, pwrseq_qca, data);
> > +     if (ret)
> > +             return ret;
> > +
> > +     if (data->has_wifi_en) {
> > +             pwrseq_qca->pwrseq_qcas[PWRSEQ_QCA_WIFI].enable = devm_gpiod_get(dev, "wifi-enable", GPIOD_OUT_LOW);
> > +             if (IS_ERR(pwrseq_qca->pwrseq_qcas[PWRSEQ_QCA_WIFI].enable)) {
> > +                     return dev_err_probe(dev, PTR_ERR(pwrseq_qca->pwrseq_qcas[PWRSEQ_QCA_WIFI].enable),
> > +                                     "failed to acquire WIFI enable GPIO\n");
> > +             }
> > +     }
> > +
> > +     if (data->has_bt_en) {
> > +             pwrseq_qca->pwrseq_qcas[PWRSEQ_QCA_BT].enable = devm_gpiod_get(dev, "bt-enable", GPIOD_OUT_LOW);
> > +             if (IS_ERR(pwrseq_qca->pwrseq_qcas[PWRSEQ_QCA_BT].enable)) {
> > +                     return dev_err_probe(dev, PTR_ERR(pwrseq_qca->pwrseq_qcas[PWRSEQ_QCA_BT].enable),
> > +                                     "failed to acquire BT enable GPIO\n");
> > +             }
> > +     }
> > +
> > +     pwrseq_qca->sw_ctrl = devm_gpiod_get_optional(dev, "swctrl", GPIOD_IN);
> > +     if (IS_ERR(pwrseq_qca->sw_ctrl)) {
> > +             return dev_err_probe(dev, PTR_ERR(pwrseq_qca->sw_ctrl),
> > +                             "failed to acquire SW_CTRL gpio\n");
> > +     } else if (!pwrseq_qca->sw_ctrl)
> > +             dev_info(dev, "No SW_CTRL gpio\n");
>
> Some {} around the else as well please.

ack

>
> Regards,
> Bjorn



-- 
With best wishes
Dmitry