drivers/pci/pwrctrl/pci-pwrctrl-pwrseq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2024 Linaro Ltd.
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/mod_devicetable.h>
   8 #include <linux/module.h>
   9 #include <linux/pci-pwrctrl.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/property.h>
  12 #include <linux/pwrseq/consumer.h>
  13 #include <linux/slab.h>
  14 #include <linux/types.h>
  15
  16 struct pci_pwrctrl_pwrseq_data {
  17         struct pci_pwrctrl ctx;
  18         struct pwrseq_desc *pwrseq;
  19 };
  20
  21 struct pci_pwrctrl_pwrseq_pdata {
  22         const char *target;
  23         /*
  24          * Called before doing anything else to perform device-specific
  25          * verification between requesting the power sequencing handle.
  26          */
  27         int (*validate_device)(struct device *dev);
  28 };
  29
  30 static int pci_pwrctrl_pwrseq_qcm_wcn_validate_device(struct device *dev)
  31 {
  32         /*
  33          * Old device trees for some platforms already define wifi nodes for
  34          * the WCN family of chips since before power sequencing was added
  35          * upstream.
  36          *
  37          * These nodes don't consume the regulator outputs from the PMU, and
  38          * if we allow this driver to bind to one of such "incomplete" nodes,
  39          * we'll see a kernel log error about the indefinite probe deferral.
  40          *
  41          * Check the existence of the regulator supply that exists on all
  42          * WCN models before moving forward.
  43          */
  44         if (!device_property_present(dev, "vddaon-supply"))
  45                 return -ENODEV;
  46
  47         return 0;
  48 }
  49
  50 static const struct pci_pwrctrl_pwrseq_pdata pci_pwrctrl_pwrseq_qcom_wcn_pdata = {
  51         .target = "wlan",
  52         .validate_device = pci_pwrctrl_pwrseq_qcm_wcn_validate_device,
  53 };
  54
  55 static void devm_pci_pwrctrl_pwrseq_power_off(void *data)
  56 {
  57         struct pwrseq_desc *pwrseq = data;
  58
  59         pwrseq_power_off(pwrseq);
  60 }
  61
  62 static int pci_pwrctrl_pwrseq_probe(struct platform_device *pdev)
  63 {
  64         const struct pci_pwrctrl_pwrseq_pdata *pdata;
  65         struct pci_pwrctrl_pwrseq_data *data;
  66         struct device *dev = &pdev->dev;
  67         int ret;
  68
  69         pdata = device_get_match_data(dev);
  70         if (!pdata || !pdata->target)
  71                 return -EINVAL;
  72
  73         if (pdata->validate_device) {
  74                 ret = pdata->validate_device(dev);
  75                 if (ret)
  76                         return ret;
  77         }
  78
  79         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
  80         if (!data)
  81                 return -ENOMEM;
  82
  83         data->pwrseq = devm_pwrseq_get(dev, pdata->target);
  84         if (IS_ERR(data->pwrseq))
  85                 return dev_err_probe(dev, PTR_ERR(data->pwrseq),
  86                                      "Failed to get the power sequencer\n");
  87
  88         ret = pwrseq_power_on(data->pwrseq);
  89         if (ret)
  90                 return dev_err_probe(dev, ret,
  91                                      "Failed to power-on the device\n");
  92
  93         ret = devm_add_action_or_reset(dev, devm_pci_pwrctrl_pwrseq_power_off,
  94                                        data->pwrseq);
  95         if (ret)
  96                 return ret;
  97
  98         pci_pwrctrl_init(&data->ctx, dev);
  99
 100         ret = devm_pci_pwrctrl_device_set_ready(dev, &data->ctx);
 101         if (ret)
 102                 return dev_err_probe(dev, ret,
 103                                      "Failed to register the pwrctrl wrapper\n");
 104
 105         return 0;
 106 }
 107
 108 static const struct of_device_id pci_pwrctrl_pwrseq_of_match[] = {
 109         {
 110                 /* ATH11K in QCA6390 package. */
 111                 .compatible = "pci17cb,1101",
 112                 .data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
 113         },
 114         {
 115                 /* ATH11K in WCN6855 package. */
 116                 .compatible = "pci17cb,1103",
 117                 .data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
 118         },
 119         {
 120                 /* ATH12K in WCN7850 package. */
 121                 .compatible = "pci17cb,1107",
 122                 .data = &pci_pwrctrl_pwrseq_qcom_wcn_pdata,
 123         },
 124         { }
 125 };
 126 MODULE_DEVICE_TABLE(of, pci_pwrctrl_pwrseq_of_match);
 127
 128 static struct platform_driver pci_pwrctrl_pwrseq_driver = {
 129         .driver = {
 130                 .name = "pci-pwrctrl-pwrseq",
 131                 .of_match_table = pci_pwrctrl_pwrseq_of_match,
 132         },
 133         .probe = pci_pwrctrl_pwrseq_probe,
 134 };
 135 module_platform_driver(pci_pwrctrl_pwrseq_driver);
 136
 137 MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>");
 138 MODULE_DESCRIPTION("Generic PCI Power Control module for power sequenced devices");
 139 MODULE_LICENSE("GPL");