David Keitel | 8927ee4 | 2013-03-19 17:25:19 -0700 | [diff] [blame] | 1 | /* Copyright (c) 2013, The Linux Foundation. All rights reserved. |
| 2 | * |
| 3 | * This program is free software; you can redistribute it and/or modify |
| 4 | * it under the terms of the GNU General Public License version 2 and |
| 5 | * only version 2 as published by the Free Software Foundation. |
| 6 | * |
| 7 | * This program is distributed in the hope that it will be useful, |
| 8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 10 | * GNU General Public License for more details. |
| 11 | */ |
| 12 | #define pr_fmt(fmt) "%s: " fmt, __func__ |
| 13 | |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/err.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/spmi.h> |
| 18 | #include <linux/of.h> |
| 19 | #include <linux/of_device.h> |
| 20 | #include <linux/qpnp-misc.h> |
| 21 | |
| 22 | #define QPNP_MISC_DEV_NAME "qcom,qpnp-misc" |
| 23 | |
| 24 | #define REVID_REVISION2 0x1 |
| 25 | |
| 26 | static DEFINE_MUTEX(qpnp_misc_dev_list_mutex); |
| 27 | static LIST_HEAD(qpnp_misc_dev_list); |
| 28 | |
| 29 | /** |
| 30 | * struct qpnp_misc_dev - holds controller device specific information |
| 31 | * @list: Doubly-linked list parameter linking to other |
| 32 | * qpnp_misc devices. |
| 33 | * @mutex: Mutex lock that is used to ensure mutual |
| 34 | * exclusion between probing and accessing misc |
| 35 | * driver information |
| 36 | * @dev: Device pointer to the misc device |
| 37 | * @resource: Resource pointer that holds base address |
| 38 | * @spmi: Spmi pointer which holds spmi information |
| 39 | */ |
| 40 | struct qpnp_misc_dev { |
| 41 | struct list_head list; |
| 42 | struct mutex mutex; |
| 43 | struct device *dev; |
| 44 | struct resource *resource; |
| 45 | struct spmi_device *spmi; |
| 46 | }; |
| 47 | |
| 48 | static struct of_device_id qpnp_misc_match_table[] = { |
| 49 | { .compatible = QPNP_MISC_DEV_NAME }, |
| 50 | {} |
| 51 | }; |
| 52 | |
| 53 | static u8 qpnp_read_byte(struct spmi_device *spmi, u16 addr) |
| 54 | { |
| 55 | int rc; |
| 56 | u8 val; |
| 57 | |
| 58 | rc = spmi_ext_register_readl(spmi->ctrl, spmi->sid, addr, &val, 1); |
| 59 | if (rc) { |
| 60 | pr_err("SPMI read failed rc=%d\n", rc); |
| 61 | return 0; |
| 62 | } |
| 63 | return val; |
| 64 | } |
| 65 | |
| 66 | #define REV2_IRQ_AVAILABLE_VERSION 2 |
| 67 | static bool __misc_irqs_available(struct qpnp_misc_dev *dev) |
| 68 | { |
| 69 | u8 rev2; |
| 70 | |
| 71 | rev2 = qpnp_read_byte(dev->spmi, |
| 72 | dev->resource->start + REVID_REVISION2); |
| 73 | pr_debug("rev2 0x%x\n", rev2); |
| 74 | |
| 75 | if (rev2 >= REV2_IRQ_AVAILABLE_VERSION) |
| 76 | return 1; |
| 77 | |
| 78 | return 0; |
| 79 | } |
| 80 | |
| 81 | int qpnp_misc_irqs_available(struct device *consumer_dev) |
| 82 | { |
| 83 | struct device_node *misc_node = NULL; |
| 84 | struct qpnp_misc_dev *mdev = NULL; |
| 85 | struct qpnp_misc_dev *mdev_found = NULL; |
| 86 | |
| 87 | misc_node = of_parse_phandle(consumer_dev->of_node, "qcom,misc-ref", 0); |
| 88 | if (!misc_node) { |
| 89 | pr_debug("Could not find qcom,misc-ref property in %s\n", |
| 90 | consumer_dev->of_node->full_name); |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | mutex_lock(&qpnp_misc_dev_list_mutex); |
| 95 | list_for_each_entry(mdev, &qpnp_misc_dev_list, list) { |
| 96 | if (mdev->dev->of_node == misc_node) { |
| 97 | mdev_found = mdev; |
| 98 | break; |
| 99 | } |
| 100 | } |
| 101 | mutex_unlock(&qpnp_misc_dev_list_mutex); |
| 102 | |
| 103 | if (!mdev_found) { |
| 104 | /* No MISC device was found. This API should only |
| 105 | * be called by drivers which have specified the |
| 106 | * misc phandle in their device tree node */ |
| 107 | pr_err("no probed misc device found\n"); |
| 108 | return -EPROBE_DEFER; |
| 109 | } |
| 110 | |
| 111 | return __misc_irqs_available(mdev_found); |
| 112 | } |
| 113 | |
| 114 | static int __devinit qpnp_misc_probe(struct spmi_device *spmi) |
| 115 | { |
| 116 | struct resource *resource; |
| 117 | struct qpnp_misc_dev *mdev = ERR_PTR(-EINVAL); |
| 118 | |
| 119 | resource = spmi_get_resource(spmi, NULL, IORESOURCE_MEM, 0); |
| 120 | if (!resource) { |
| 121 | pr_err("Unable to get spmi resource for MISC\n"); |
| 122 | return -EINVAL; |
| 123 | } |
| 124 | |
| 125 | mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); |
| 126 | if (!mdev) { |
| 127 | pr_err("allocation failed\n"); |
| 128 | return -ENOMEM; |
| 129 | } |
| 130 | |
| 131 | mdev->spmi = spmi; |
| 132 | mdev->dev = &(spmi->dev); |
| 133 | mdev->resource = resource; |
| 134 | |
| 135 | mutex_lock(&qpnp_misc_dev_list_mutex); |
| 136 | list_add_tail(&mdev->list, &qpnp_misc_dev_list); |
| 137 | mutex_unlock(&qpnp_misc_dev_list_mutex); |
| 138 | |
| 139 | pr_debug("probed successfully\n"); |
| 140 | return 0; |
| 141 | } |
| 142 | |
| 143 | static struct spmi_driver qpnp_misc_driver = { |
| 144 | .probe = qpnp_misc_probe, |
| 145 | .driver = { |
| 146 | .name = QPNP_MISC_DEV_NAME, |
| 147 | .owner = THIS_MODULE, |
| 148 | .of_match_table = qpnp_misc_match_table, |
| 149 | }, |
| 150 | }; |
| 151 | |
| 152 | static int __init qpnp_misc_init(void) |
| 153 | { |
| 154 | return spmi_driver_register(&qpnp_misc_driver); |
| 155 | } |
| 156 | |
| 157 | static void __exit qpnp_misc_exit(void) |
| 158 | { |
| 159 | return spmi_driver_unregister(&qpnp_misc_driver); |
| 160 | } |
| 161 | |
| 162 | module_init(qpnp_misc_init); |
| 163 | module_exit(qpnp_misc_exit); |
| 164 | |
| 165 | MODULE_DESCRIPTION(QPNP_MISC_DEV_NAME); |
| 166 | MODULE_LICENSE("GPL v2"); |
| 167 | MODULE_ALIAS("platform:" QPNP_MISC_DEV_NAME); |