/drivers/mfd/mfd-core.c

  1/*
  2 * drivers/mfd/mfd-core.c
  3 *
  4 * core MFD support
  5 * Copyright (c) 2006 Ian Molton
  6 * Copyright (c) 2007,2008 Dmitry Baryshkov
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License version 2 as
 10 * published by the Free Software Foundation.
 11 *
 12 */
 13
 14#include <linux/kernel.h>
 15#include <linux/platform_device.h>
 16#include <linux/acpi.h>
 17#include <linux/mfd/core.h>
 18#include <linux/pm_runtime.h>
 19#include <linux/slab.h>
 20
 21int mfd_cell_enable(struct platform_device *pdev)
 22{
 23	const struct mfd_cell *cell = mfd_get_cell(pdev);
 24	int err = 0;
 25
 26	/* only call enable hook if the cell wasn't previously enabled */
 27	if (atomic_inc_return(cell->usage_count) == 1)
 28		err = cell->enable(pdev);
 29
 30	/* if the enable hook failed, decrement counter to allow retries */
 31	if (err)
 32		atomic_dec(cell->usage_count);
 33
 34	return err;
 35}
 36EXPORT_SYMBOL(mfd_cell_enable);
 37
 38int mfd_cell_disable(struct platform_device *pdev)
 39{
 40	const struct mfd_cell *cell = mfd_get_cell(pdev);
 41	int err = 0;
 42
 43	/* only disable if no other clients are using it */
 44	if (atomic_dec_return(cell->usage_count) == 0)
 45		err = cell->disable(pdev);
 46
 47	/* if the disable hook failed, increment to allow retries */
 48	if (err)
 49		atomic_inc(cell->usage_count);
 50
 51	/* sanity check; did someone call disable too many times? */
 52	WARN_ON(atomic_read(cell->usage_count) < 0);
 53
 54	return err;
 55}
 56EXPORT_SYMBOL(mfd_cell_disable);
 57
 58static int mfd_platform_add_cell(struct platform_device *pdev,
 59				 const struct mfd_cell *cell)
 60{
 61	if (!cell)
 62		return 0;
 63
 64	pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL);
 65	if (!pdev->mfd_cell)
 66		return -ENOMEM;
 67
 68	return 0;
 69}
 70
 71static int mfd_add_device(struct device *parent, int id,
 72			  const struct mfd_cell *cell,
 73			  struct resource *mem_base,
 74			  int irq_base)
 75{
 76	struct resource *res;
 77	struct platform_device *pdev;
 78	int ret = -ENOMEM;
 79	int r;
 80
 81	pdev = platform_device_alloc(cell->name, id + cell->id);
 82	if (!pdev)
 83		goto fail_alloc;
 84
 85	res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL);
 86	if (!res)
 87		goto fail_device;
 88
 89	pdev->dev.parent = parent;
 90
 91	if (cell->pdata_size) {
 92		ret = platform_device_add_data(pdev,
 93					cell->platform_data, cell->pdata_size);
 94		if (ret)
 95			goto fail_res;
 96	}
 97
 98	ret = mfd_platform_add_cell(pdev, cell);
 99	if (ret)
100		goto fail_res;
101
102	for (r = 0; r < cell->num_resources; r++) {
103		res[r].name = cell->resources[r].name;
104		res[r].flags = cell->resources[r].flags;
105
106		/* Find out base to use */
107		if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) {
108			res[r].parent = mem_base;
109			res[r].start = mem_base->start +
110				cell->resources[r].start;
111			res[r].end = mem_base->start +
112				cell->resources[r].end;
113		} else if (cell->resources[r].flags & IORESOURCE_IRQ) {
114			res[r].start = irq_base +
115				cell->resources[r].start;
116			res[r].end   = irq_base +
117				cell->resources[r].end;
118		} else {
119			res[r].parent = cell->resources[r].parent;
120			res[r].start = cell->resources[r].start;
121			res[r].end   = cell->resources[r].end;
122		}
123
124		if (!cell->ignore_resource_conflicts) {
125			ret = acpi_check_resource_conflict(&res[r]);
126			if (ret)
127				goto fail_res;
128		}
129	}
130
131	ret = platform_device_add_resources(pdev, res, cell->num_resources);
132	if (ret)
133		goto fail_res;
134
135	ret = platform_device_add(pdev);
136	if (ret)
137		goto fail_res;
138
139	if (cell->pm_runtime_no_callbacks)
140		pm_runtime_no_callbacks(&pdev->dev);
141
142	kfree(res);
143
144	return 0;
145
146fail_res:
147	kfree(res);
148fail_device:
149	platform_device_put(pdev);
150fail_alloc:
151	return ret;
152}
153
154int mfd_add_devices(struct device *parent, int id,
155		    struct mfd_cell *cells, int n_devs,
156		    struct resource *mem_base,
157		    int irq_base)
158{
159	int i;
160	int ret = 0;
161	atomic_t *cnts;
162
163	/* initialize reference counting for all cells */
164	cnts = kcalloc(sizeof(*cnts), n_devs, GFP_KERNEL);
165	if (!cnts)
166		return -ENOMEM;
167
168	for (i = 0; i < n_devs; i++) {
169		atomic_set(&cnts[i], 0);
170		cells[i].usage_count = &cnts[i];
171		ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base);
172		if (ret)
173			break;
174	}
175
176	if (ret)
177		mfd_remove_devices(parent);
178
179	return ret;
180}
181EXPORT_SYMBOL(mfd_add_devices);
182
183static int mfd_remove_devices_fn(struct device *dev, void *c)
184{
185	struct platform_device *pdev = to_platform_device(dev);
186	const struct mfd_cell *cell = mfd_get_cell(pdev);
187	atomic_t **usage_count = c;
188
189	/* find the base address of usage_count pointers (for freeing) */
190	if (!*usage_count || (cell->usage_count < *usage_count))
191		*usage_count = cell->usage_count;
192
193	platform_device_unregister(pdev);
194	return 0;
195}
196
197void mfd_remove_devices(struct device *parent)
198{
199	atomic_t *cnts = NULL;
200
201	device_for_each_child(parent, &cnts, mfd_remove_devices_fn);
202	kfree(cnts);
203}
204EXPORT_SYMBOL(mfd_remove_devices);
205
206int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones)
207{
208	struct mfd_cell cell_entry;
209	struct device *dev;
210	struct platform_device *pdev;
211	int i;
212
213	/* fetch the parent cell's device (should already be registered!) */
214	dev = bus_find_device_by_name(&platform_bus_type, NULL, cell);
215	if (!dev) {
216		printk(KERN_ERR "failed to find device for cell %s\n", cell);
217		return -ENODEV;
218	}
219	pdev = to_platform_device(dev);
220	memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry));
221
222	WARN_ON(!cell_entry.enable);
223
224	for (i = 0; i < n_clones; i++) {
225		cell_entry.name = clones[i];
226		/* don't give up if a single call fails; just report error */
227		if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0))
228			dev_err(dev, "failed to create platform device '%s'\n",
229					clones[i]);
230	}
231
232	return 0;
233}
234EXPORT_SYMBOL(mfd_clone_cell);
235
236MODULE_LICENSE("GPL");
237MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov");