[PATCH v7 16/16] PCI/pwrctl: add a PCI power control driver for power sequenced devices

Bartosz Golaszewski
2024-04-10T12:47:16Z

Add a PCI power control driver that's capable of correctly powering up
devices using the power sequencing subsystem. The first user of this
driver is the ath11k module on QCA6390.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
drivers/pci/pwrctl/Kconfig | 9 +++
drivers/pci/pwrctl/Makefile | 2 +
drivers/pci/pwrctl/pci-pwrctl-pwrseq.c | 89 ++++++++++++++++++++++++++
3 files changed, 100 insertions(+)
create mode 100644 drivers/pci/pwrctl/pci-pwrctl-pwrseq.c

diff --git a/drivers/pci/pwrctl/Kconfig b/drivers/pci/pwrctl/Kconfig
index 96195395af69..eb126225eb9f 100644
--- a/drivers/pci/pwrctl/Kconfig
+++ b/drivers/pci/pwrctl/Kconfig
@@ -5,4 +5,13 @@ menu "PCI Power control drivers"
config PCI_PWRCTL
tristate

+config PCI_PWRCTL_PWRSEQ
+ tristate "PCI Power Control driver using the Power Sequencing subsystem"
+ select POWER_SEQUENCING
+ select PCI_PWRCTL
+ default m if (ATH11K_PCI && ARCH_QCOM)
+ help
+ Enable support for the PCI power control driver for device
+ drivers using the Power Sequencing subsystem.
+
endmenu
diff --git a/drivers/pci/pwrctl/Makefile b/drivers/pci/pwrctl/Makefile
index 52ae0640ef7b..d308aae4800c 100644
--- a/drivers/pci/pwrctl/Makefile
+++ b/drivers/pci/pwrctl/Makefile
@@ -2,3 +2,5 @@

obj-$(CONFIG_PCI_PWRCTL) += pci-pwrctl-core.o
pci-pwrctl-core-y := core.o
+
+obj-$(CONFIG_PCI_PWRCTL_PWRSEQ) += pci-pwrctl-pwrseq.o
diff --git a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
new file mode 100644
index 000000000000..c7a113a76c0c
--- /dev/null
+++ b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 Linaro Ltd.
+ */
+
+#include <linux/device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pci-pwrctl.h>
+#include <linux/platform_device.h>
+#include <linux/pwrseq/consumer.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+struct pci_pwrctl_pwrseq_data {
+ struct pci_pwrctl ctx;
+ struct pwrseq_desc *pwrseq;
+};
+
+static void devm_pci_pwrctl_pwrseq_power_off(void *data)
+{
+ struct pwrseq_desc *pwrseq = data;
+
+ pwrseq_power_off(pwrseq);
+}
+
+static int pci_pwrctl_pwrseq_probe(struct platform_device *pdev)
+{
+ struct pci_pwrctl_pwrseq_data *data;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->pwrseq = devm_pwrseq_get(dev, of_device_get_match_data(dev));
+ if (IS_ERR(data->pwrseq))
+ return dev_err_probe(dev, PTR_ERR(data->pwrseq),
+ "Failed to get the power sequencer\n");
+
+ ret = pwrseq_power_on(data->pwrseq);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to power-on the device\n");
+
+ ret = devm_add_action_or_reset(dev, devm_pci_pwrctl_pwrseq_power_off,
+ data->pwrseq);
+ if (ret)
+ return ret;
+
+ data->ctx.dev = dev;
+
+ ret = devm_pci_pwrctl_device_set_ready(dev, &data->ctx);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to register the pwrctl wrapper\n");
+
+ return 0;
+}
+
+static const struct of_device_id pci_pwrctl_pwrseq_of_match[] = {
+ {
+ /* ATH11K in QCA6390 package. */
+ .compatible = "pci17cb,1101",
+ .data = "wlan",
+ },
+ {
+ /* ATH12K in WCN7850 package. */
+ .compatible = "pci17cb,1107",
+ .data = "wlan",
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(of, pci_pwrctl_pwrseq_of_match);
+
+static struct platform_driver pci_pwrctl_pwrseq_driver = {
+ .driver = {
+ .name = "pci-pwrctl-pwrseq",
+ .of_match_table = pci_pwrctl_pwrseq_of_match,
+ },
+ .probe = pci_pwrctl_pwrseq_probe,
+};
+module_platform_driver(pci_pwrctl_pwrseq_driver);
+
+MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>");
+MODULE_DESCRIPTION("Generic PCI Power Control module for power sequenced devices");
+MODULE_LICENSE("GPL");
--
2.40.1