[RFC v2 06/13] pwrseq: pwrseq_qca: implement fallback support

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

While we are waiting for all users of wcn399x-bt to be converted to the
pwrseq declaration in the device tree, provide support for the pwrseq
fallback: if the regulators are declared in the device itself, create
pwrseq instance. This way the hci_qca driver doesn't have to cope with
old and new dts bindings.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/power/pwrseq/pwrseq_qca.c | 148 +++++++++++++++++++++++++++++-
 1 file changed, 147 insertions(+), 1 deletion(-)

diff --git a/drivers/power/pwrseq/pwrseq_qca.c b/drivers/power/pwrseq/pwrseq_qca.c
index 7aa5f2d94039..d01f1ef4626b 100644
--- a/drivers/power/pwrseq/pwrseq_qca.c
+++ b/drivers/power/pwrseq/pwrseq_qca.c
@@ -11,9 +11,11 @@
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/mod_devicetable.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/pwrseq/driver.h>
+#include <linux/pwrseq/fallback.h>
 #include <linux/regulator/consumer.h>
 
 /* susclk rate */
@@ -367,5 +369,149 @@ static struct platform_driver pwrseq_qca_driver = {
 	},
 };
 
-module_platform_driver(pwrseq_qca_driver);
+struct pwrseq_qca_fallback {
+	struct pwrseq_qca_one qca_one;
+	struct pwrseq_qca_common common;
+};
+
+static const struct of_device_id pwrseq_qca_bt_of_match[] = {
+	{ .compatible = "qcom,qca6174-bt" },
+	{ .compatible = "qcom,qca6390-bt", .data = &qca_soc_data_qca6390},
+	{ .compatible = "qcom,qca9377-bt" },
+	{ .compatible = "qcom,wcn3990-bt", .data = &qca_soc_data_wcn3990 },
+	{ .compatible = "qcom,wcn3991-bt", .data = &qca_soc_data_wcn3990 },
+	{ .compatible = "qcom,wcn3998-bt", .data = &qca_soc_data_wcn3998 },
+	{ .compatible = "qcom,wcn6750-bt", .data = &qca_soc_data_wcn6750 },
+	{ /* sentinel */ },
+};
+
+static const struct qca_device_data qca_soc_data_wifi = {
+	.vregs = {
+		{ "vdd-1.8-xo", 80000  },
+		{ "vdd-1.3-rfa", 300000 },
+		{ "vdd-3.3-ch0", 450000 },
+		{ "vdd-3.3-ch1", 450000 },
+	},
+	.num_vregs = 4,
+};
+
+static const struct of_device_id pwrseq_qca_wifi_of_match[] = {
+	{ .compatible = "qcom,wcn3990-wifi", .data = &qca_soc_data_wifi },
+	{ /* sentinel */ }
+};
+
+static struct pwrseq * pwrseq_qca_fallback_get(struct device *dev)
+{
+	struct pwrseq_qca_fallback *fallback;
+	const struct of_device_id *match;
+	const struct qca_device_data *data;
+	struct gpio_desc *gpiod;
+	int ret;
+
+	match = of_match_device(pwrseq_qca_bt_of_match, dev);
+	if (!match)
+		return ERR_PTR(-ENODEV);
+
+	data = match->data;
+	if (!data)
+		data = &qca_soc_data_default;
+
+	fallback = devm_kzalloc(dev, struct_size(fallback, common.vregs, data->num_vregs), GFP_KERNEL);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+
+	fallback->qca_one.common = &fallback->common;
+
+	ret = pwrseq_qca_common_init(dev, &fallback->common, data);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (data->has_enable_gpios) {
+		gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+		if (IS_ERR(gpiod))
+			return ERR_PTR(dev_err_probe(dev, PTR_ERR(gpiod), "failed to acquire enable GPIO\n"));
+		fallback->qca_one.enable = gpiod;
+	}
+
+	/* If we have no control over device's enablement, make sure that sleep clock is always running */
+	if (!fallback->common.vddio ||
+	    !fallback->common.num_vregs ||
+	    !fallback->qca_one.enable) {
+		ret = clk_set_rate(fallback->common.susclk, SUSCLK_RATE_32KHZ);
+		if (ret)
+			return ERR_PTR(ret);
+
+		ret = clk_prepare_enable(fallback->common.susclk);
+		if (ret)
+			return ERR_PTR(ret);
+
+		ret = devm_add_action_or_reset(dev, pwrseq_qca_unprepare_susclk, &fallback->common);
+		if (ret)
+			return ERR_PTR(ret);
+	}
+
+	return devm_pwrseq_create(dev, &pwrseq_qca_ops, &fallback->qca_one);
+}
+
+static struct pwrseq * pwrseq_qca_fallback_get_bt(struct device *dev, const char *id)
+{
+	if (strcmp(id, "bt"))
+		return ERR_PTR(-ENODEV);
+
+	return pwrseq_qca_fallback_get(dev);
+}
+
+static struct pwrseq * pwrseq_qca_fallback_get_wifi(struct device *dev, const char *id)
+{
+	if (strcmp(id, "wifi"))
+		return ERR_PTR(-ENODEV);
+
+	return pwrseq_qca_fallback_get(dev);
+}
+
+static struct pwrseq_fallback pwrseq_qca_fallback_bt = {
+	.get = pwrseq_qca_fallback_get_bt,
+	.of_match_table = pwrseq_qca_bt_of_match,
+};
+
+static struct pwrseq_fallback pwrseq_qca_fallback_wifi = {
+	.get = pwrseq_qca_fallback_get_wifi,
+	.of_match_table = pwrseq_qca_wifi_of_match,
+};
+
+static int __init pwrseq_qca_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&pwrseq_qca_driver);
+	if (ret)
+		return ret;
+
+	ret = pwrseq_fallback_register(&pwrseq_qca_fallback_bt);
+	if (ret)
+		goto err_bt;
+
+	ret = pwrseq_fallback_register(&pwrseq_qca_fallback_wifi);
+	if (ret)
+		goto err_wifi;
+
+	return 0;
+
+err_wifi:
+	pwrseq_fallback_unregister(&pwrseq_qca_fallback_bt);
+err_bt:
+	platform_driver_unregister(&pwrseq_qca_driver);
+
+	return ret;
+}
+module_init(pwrseq_qca_init);
+
+static void __exit pwrseq_qca_exit(void)
+{
+	pwrseq_fallback_unregister(&pwrseq_qca_fallback_wifi);
+	pwrseq_fallback_unregister(&pwrseq_qca_fallback_bt);
+	platform_driver_unregister(&pwrseq_qca_driver);
+}
+module_exit(pwrseq_qca_exit);
+
 MODULE_LICENSE("GPL v2");
-- 
2.33.0