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  1/*
  2 * AppliedMicro X-Gene SoC GPIO-Standby Driver
  3 *
  4 * Copyright (c) 2014, Applied Micro Circuits Corporation
  5 * Author:	Tin Huynh <tnhuynh@apm.com>.
  6 *		Y Vo <yvo@apm.com>.
  7 *		Quan Nguyen <qnguyen@apm.com>.
  8 *
  9 * This program is free software; you can redistribute  it and/or modify it
 10 * under  the terms of  the GNU General  Public License as published by the
 11 * Free Software Foundation;  either version 2 of the  License, or (at your
 12 * option) any later version.
 13 *
 14 * This program is distributed in the hope that it will be useful,
 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17 * GNU General Public License for more details.
 18 *
 19 * You should have received a copy of the GNU General Public License
 20 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 21 */
 22
 23#include <linux/module.h>
 24#include <linux/io.h>
 25#include <linux/platform_device.h>
 26#include <linux/of_gpio.h>
 27#include <linux/gpio/driver.h>
 28#include <linux/acpi.h>
 29
 30#include "gpiolib.h"
 31
 32/* Common property names */
 33#define XGENE_NIRQ_PROPERTY		"apm,nr-irqs"
 34#define XGENE_NGPIO_PROPERTY		"apm,nr-gpios"
 35#define XGENE_IRQ_START_PROPERTY	"apm,irq-start"
 36
 37#define XGENE_DFLT_MAX_NGPIO		22
 38#define XGENE_DFLT_MAX_NIRQ		6
 39#define XGENE_DFLT_IRQ_START_PIN	8
 40#define GPIO_MASK(x)			(1U << ((x) % 32))
 41
 42#define MPA_GPIO_INT_LVL		0x0290
 43#define MPA_GPIO_OE_ADDR		0x029c
 44#define MPA_GPIO_OUT_ADDR		0x02a0
 45#define MPA_GPIO_IN_ADDR 		0x02a4
 46#define MPA_GPIO_SEL_LO 		0x0294
 47
 48#define GPIO_INT_LEVEL_H	0x000001
 49#define GPIO_INT_LEVEL_L	0x000000
 50
 51/**
 52 * struct xgene_gpio_sb - GPIO-Standby private data structure.
 53 * @gc:				memory-mapped GPIO controllers.
 54 * @regs:			GPIO register base offset
 55 * @irq_domain:			GPIO interrupt domain
 56 * @irq_start:			GPIO pin that start support interrupt
 57 * @nirq:			Number of GPIO pins that supports interrupt
 58 * @parent_irq_base:		Start parent HWIRQ
 59 */
 60struct xgene_gpio_sb {
 61	struct gpio_chip	gc;
 62	void __iomem		*regs;
 63	struct irq_domain	*irq_domain;
 64	u16			irq_start;
 65	u16			nirq;
 66	u16			parent_irq_base;
 67};
 68
 69#define HWIRQ_TO_GPIO(priv, hwirq) ((hwirq) + (priv)->irq_start)
 70#define GPIO_TO_HWIRQ(priv, gpio) ((gpio) - (priv)->irq_start)
 71
 72static void xgene_gpio_set_bit(struct gpio_chip *gc,
 73				void __iomem *reg, u32 gpio, int val)
 74{
 75	u32 data;
 76
 77	data = gc->read_reg(reg);
 78	if (val)
 79		data |= GPIO_MASK(gpio);
 80	else
 81		data &= ~GPIO_MASK(gpio);
 82	gc->write_reg(reg, data);
 83}
 84
 85static int xgene_gpio_sb_irq_set_type(struct irq_data *d, unsigned int type)
 86{
 87	struct xgene_gpio_sb *priv = irq_data_get_irq_chip_data(d);
 88	int gpio = HWIRQ_TO_GPIO(priv, d->hwirq);
 89	int lvl_type = GPIO_INT_LEVEL_H;
 90
 91	switch (type & IRQ_TYPE_SENSE_MASK) {
 92	case IRQ_TYPE_EDGE_RISING:
 93	case IRQ_TYPE_LEVEL_HIGH:
 94		lvl_type = GPIO_INT_LEVEL_H;
 95		break;
 96	case IRQ_TYPE_EDGE_FALLING:
 97	case IRQ_TYPE_LEVEL_LOW:
 98		lvl_type = GPIO_INT_LEVEL_L;
 99		break;
100	default:
101		break;
102	}
103
104	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
105			gpio * 2, 1);
106	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_INT_LVL,
107			d->hwirq, lvl_type);
108
109	/* Propagate IRQ type setting to parent */
110	if (type & IRQ_TYPE_EDGE_BOTH)
111		return irq_chip_set_type_parent(d, IRQ_TYPE_EDGE_RISING);
112	else
113		return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
114}
115
116static struct irq_chip xgene_gpio_sb_irq_chip = {
117	.name           = "sbgpio",
118	.irq_eoi	= irq_chip_eoi_parent,
119	.irq_mask       = irq_chip_mask_parent,
120	.irq_unmask     = irq_chip_unmask_parent,
121	.irq_set_type   = xgene_gpio_sb_irq_set_type,
122};
123
124static int xgene_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
125{
126	struct xgene_gpio_sb *priv = gpiochip_get_data(gc);
127	struct irq_fwspec fwspec;
128
129	if ((gpio < priv->irq_start) ||
130			(gpio > HWIRQ_TO_GPIO(priv, priv->nirq)))
131		return -ENXIO;
132
133	if (gc->parent->of_node)
134		fwspec.fwnode = of_node_to_fwnode(gc->parent->of_node);
135	else
136		fwspec.fwnode = gc->parent->fwnode;
137	fwspec.param_count = 2;
138	fwspec.param[0] = GPIO_TO_HWIRQ(priv, gpio);
139	fwspec.param[1] = IRQ_TYPE_NONE;
140	return irq_create_fwspec_mapping(&fwspec);
141}
142
143static void xgene_gpio_sb_domain_activate(struct irq_domain *d,
144		struct irq_data *irq_data)
145{
146	struct xgene_gpio_sb *priv = d->host_data;
147	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
148
149	if (gpiochip_lock_as_irq(&priv->gc, gpio)) {
150		dev_err(priv->gc.parent,
151		"Unable to configure XGene GPIO standby pin %d as IRQ\n",
152				gpio);
153		return;
154	}
155
156	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
157			gpio * 2, 1);
158}
159
160static void xgene_gpio_sb_domain_deactivate(struct irq_domain *d,
161		struct irq_data *irq_data)
162{
163	struct xgene_gpio_sb *priv = d->host_data;
164	u32 gpio = HWIRQ_TO_GPIO(priv, irq_data->hwirq);
165
166	gpiochip_unlock_as_irq(&priv->gc, gpio);
167	xgene_gpio_set_bit(&priv->gc, priv->regs + MPA_GPIO_SEL_LO,
168			gpio * 2, 0);
169}
170
171static int xgene_gpio_sb_domain_translate(struct irq_domain *d,
172		struct irq_fwspec *fwspec,
173		unsigned long *hwirq,
174		unsigned int *type)
175{
176	struct xgene_gpio_sb *priv = d->host_data;
177
178	if ((fwspec->param_count != 2) ||
179		(fwspec->param[0] >= priv->nirq))
180		return -EINVAL;
181	*hwirq = fwspec->param[0];
182	*type = fwspec->param[1];
183	return 0;
184}
185
186static int xgene_gpio_sb_domain_alloc(struct irq_domain *domain,
187					unsigned int virq,
188					unsigned int nr_irqs, void *data)
189{
190	struct irq_fwspec *fwspec = data;
191	struct irq_fwspec parent_fwspec;
192	struct xgene_gpio_sb *priv = domain->host_data;
193	irq_hw_number_t hwirq;
194	unsigned int i;
195
196	hwirq = fwspec->param[0];
197	for (i = 0; i < nr_irqs; i++)
198		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
199				&xgene_gpio_sb_irq_chip, priv);
200
201	parent_fwspec.fwnode = domain->parent->fwnode;
202	if (is_of_node(parent_fwspec.fwnode)) {
203		parent_fwspec.param_count = 3;
204		parent_fwspec.param[0] = 0;/* SPI */
205		/* Skip SGIs and PPIs*/
206		parent_fwspec.param[1] = hwirq + priv->parent_irq_base - 32;
207		parent_fwspec.param[2] = fwspec->param[1];
208	} else if (is_fwnode_irqchip(parent_fwspec.fwnode)) {
209		parent_fwspec.param_count = 2;
210		parent_fwspec.param[0] = hwirq + priv->parent_irq_base;
211		parent_fwspec.param[1] = fwspec->param[1];
212	} else
213		return -EINVAL;
214
215	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
216			&parent_fwspec);
217}
218
219static void xgene_gpio_sb_domain_free(struct irq_domain *domain,
220		unsigned int virq,
221		unsigned int nr_irqs)
222{
223	struct irq_data *d;
224	unsigned int i;
225
226	for (i = 0; i < nr_irqs; i++) {
227		d = irq_domain_get_irq_data(domain, virq + i);
228		irq_domain_reset_irq_data(d);
229	}
230}
231
232static const struct irq_domain_ops xgene_gpio_sb_domain_ops = {
233	.translate      = xgene_gpio_sb_domain_translate,
234	.alloc          = xgene_gpio_sb_domain_alloc,
235	.free           = xgene_gpio_sb_domain_free,
236	.activate	= xgene_gpio_sb_domain_activate,
237	.deactivate	= xgene_gpio_sb_domain_deactivate,
238};
239
240static int xgene_gpio_sb_probe(struct platform_device *pdev)
241{
242	struct xgene_gpio_sb *priv;
243	int ret;
244	struct resource *res;
245	void __iomem *regs;
246	struct irq_domain *parent_domain = NULL;
247	struct fwnode_handle *fwnode;
248	u32 val32;
249
250	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
251	if (!priv)
252		return -ENOMEM;
253
254	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
255	regs = devm_ioremap_resource(&pdev->dev, res);
256	if (IS_ERR(regs))
257		return PTR_ERR(regs);
258
259	priv->regs = regs;
260
261	ret = platform_get_irq(pdev, 0);
262	if (ret > 0) {
263		priv->parent_irq_base = irq_get_irq_data(ret)->hwirq;
264		parent_domain = irq_get_irq_data(ret)->domain;
265	}
266	if (!parent_domain) {
267		dev_err(&pdev->dev, "unable to obtain parent domain\n");
268		return -ENODEV;
269	}
270
271	ret = bgpio_init(&priv->gc, &pdev->dev, 4,
272			regs + MPA_GPIO_IN_ADDR,
273			regs + MPA_GPIO_OUT_ADDR, NULL,
274			regs + MPA_GPIO_OE_ADDR, NULL, 0);
275        if (ret)
276                return ret;
277
278	priv->gc.to_irq = xgene_gpio_sb_to_irq;
279
280	/* Retrieve start irq pin, use default if property not found */
281	priv->irq_start = XGENE_DFLT_IRQ_START_PIN;
282	if (!device_property_read_u32(&pdev->dev,
283					XGENE_IRQ_START_PROPERTY, &val32))
284		priv->irq_start = val32;
285
286	/* Retrieve number irqs, use default if property not found */
287	priv->nirq = XGENE_DFLT_MAX_NIRQ;
288	if (!device_property_read_u32(&pdev->dev, XGENE_NIRQ_PROPERTY, &val32))
289		priv->nirq = val32;
290
291	/* Retrieve number gpio, use default if property not found */
292	priv->gc.ngpio = XGENE_DFLT_MAX_NGPIO;
293	if (!device_property_read_u32(&pdev->dev, XGENE_NGPIO_PROPERTY, &val32))
294		priv->gc.ngpio = val32;
295
296	dev_info(&pdev->dev, "Support %d gpios, %d irqs start from pin %d\n",
297			priv->gc.ngpio, priv->nirq, priv->irq_start);
298
299	platform_set_drvdata(pdev, priv);
300
301	if (pdev->dev.of_node)
302		fwnode = of_node_to_fwnode(pdev->dev.of_node);
303	else
304		fwnode = pdev->dev.fwnode;
305
306	priv->irq_domain = irq_domain_create_hierarchy(parent_domain,
307					0, priv->nirq, fwnode,
308					&xgene_gpio_sb_domain_ops, priv);
309	if (!priv->irq_domain)
310		return -ENODEV;
311
312	priv->gc.irqdomain = priv->irq_domain;
313
314	ret = devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
315	if (ret) {
316		dev_err(&pdev->dev,
317			"failed to register X-Gene GPIO Standby driver\n");
318		irq_domain_remove(priv->irq_domain);
319		return ret;
320	}
321
322	dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
323
324	if (priv->nirq > 0) {
325		/* Register interrupt handlers for gpio signaled acpi events */
326		acpi_gpiochip_request_interrupts(&priv->gc);
327	}
328
329	return ret;
330}
331
332static int xgene_gpio_sb_remove(struct platform_device *pdev)
333{
334	struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);
335
336	if (priv->nirq > 0) {
337		acpi_gpiochip_free_interrupts(&priv->gc);
338	}
339
340	irq_domain_remove(priv->irq_domain);
341
342	return 0;
343}
344
345static const struct of_device_id xgene_gpio_sb_of_match[] = {
346	{.compatible = "apm,xgene-gpio-sb", },
347	{},
348};
349MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);
350
351#ifdef CONFIG_ACPI
352static const struct acpi_device_id xgene_gpio_sb_acpi_match[] = {
353	{"APMC0D15", 0},
354	{},
355};
356MODULE_DEVICE_TABLE(acpi, xgene_gpio_sb_acpi_match);
357#endif
358
359static struct platform_driver xgene_gpio_sb_driver = {
360	.driver = {
361		   .name = "xgene-gpio-sb",
362		   .of_match_table = xgene_gpio_sb_of_match,
363		   .acpi_match_table = ACPI_PTR(xgene_gpio_sb_acpi_match),
364		   },
365	.probe = xgene_gpio_sb_probe,
366	.remove = xgene_gpio_sb_remove,
367};
368module_platform_driver(xgene_gpio_sb_driver);
369
370MODULE_AUTHOR("AppliedMicro");
371MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
372MODULE_LICENSE("GPL");