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  1/*
  2 * Intel MID GPIO driver
  3 *
  4 * Copyright (c) 2008-2014,2016 Intel Corporation.
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 */
 15
 16/* Supports:
 17 * Moorestown platform Langwell chip.
 18 * Medfield platform Penwell chip.
 19 * Clovertrail platform Cloverview chip.
 20 */
 21
 22#include <linux/delay.h>
 23#include <linux/init.h>
 24#include <linux/interrupt.h>
 25#include <linux/io.h>
 26#include <linux/gpio/driver.h>
 27#include <linux/kernel.h>
 28#include <linux/module.h>
 29#include <linux/pci.h>
 30#include <linux/platform_device.h>
 31#include <linux/pm_runtime.h>
 32#include <linux/slab.h>
 33#include <linux/stddef.h>
 34
 35#define INTEL_MID_IRQ_TYPE_EDGE		(1 << 0)
 36#define INTEL_MID_IRQ_TYPE_LEVEL	(1 << 1)
 37
 38/*
 39 * Langwell chip has 64 pins and thus there are 2 32bit registers to control
 40 * each feature, while Penwell chip has 96 pins for each block, and need 3 32bit
 41 * registers to control them, so we only define the order here instead of a
 42 * structure, to get a bit offset for a pin (use GPDR as an example):
 43 *
 44 * nreg = ngpio / 32;
 45 * reg = offset / 32;
 46 * bit = offset % 32;
 47 * reg_addr = reg_base + GPDR * nreg * 4 + reg * 4;
 48 *
 49 * so the bit of reg_addr is to control pin offset's GPDR feature
 50*/
 51
 52enum GPIO_REG {
 53	GPLR = 0,	/* pin level read-only */
 54	GPDR,		/* pin direction */
 55	GPSR,		/* pin set */
 56	GPCR,		/* pin clear */
 57	GRER,		/* rising edge detect */
 58	GFER,		/* falling edge detect */
 59	GEDR,		/* edge detect result */
 60	GAFR,		/* alt function */
 61};
 62
 63/* intel_mid gpio driver data */
 64struct intel_mid_gpio_ddata {
 65	u16 ngpio;		/* number of gpio pins */
 66	u32 chip_irq_type;	/* chip interrupt type */
 67};
 68
 69struct intel_mid_gpio {
 70	struct gpio_chip		chip;
 71	void __iomem			*reg_base;
 72	spinlock_t			lock;
 73	struct pci_dev			*pdev;
 74};
 75
 76static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
 77			      enum GPIO_REG reg_type)
 78{
 79	struct intel_mid_gpio *priv = gpiochip_get_data(chip);
 80	unsigned nreg = chip->ngpio / 32;
 81	u8 reg = offset / 32;
 82
 83	return priv->reg_base + reg_type * nreg * 4 + reg * 4;
 84}
 85
 86static void __iomem *gpio_reg_2bit(struct gpio_chip *chip, unsigned offset,
 87				   enum GPIO_REG reg_type)
 88{
 89	struct intel_mid_gpio *priv = gpiochip_get_data(chip);
 90	unsigned nreg = chip->ngpio / 32;
 91	u8 reg = offset / 16;
 92
 93	return priv->reg_base + reg_type * nreg * 4 + reg * 4;
 94}
 95
 96static int intel_gpio_request(struct gpio_chip *chip, unsigned offset)
 97{
 98	void __iomem *gafr = gpio_reg_2bit(chip, offset, GAFR);
 99	u32 value = readl(gafr);
100	int shift = (offset % 16) << 1, af = (value >> shift) & 3;
101
102	if (af) {
103		value &= ~(3 << shift);
104		writel(value, gafr);
105	}
106	return 0;
107}
108
109static int intel_gpio_get(struct gpio_chip *chip, unsigned offset)
110{
111	void __iomem *gplr = gpio_reg(chip, offset, GPLR);
112
113	return !!(readl(gplr) & BIT(offset % 32));
114}
115
116static void intel_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
117{
118	void __iomem *gpsr, *gpcr;
119
120	if (value) {
121		gpsr = gpio_reg(chip, offset, GPSR);
122		writel(BIT(offset % 32), gpsr);
123	} else {
124		gpcr = gpio_reg(chip, offset, GPCR);
125		writel(BIT(offset % 32), gpcr);
126	}
127}
128
129static int intel_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
130{
131	struct intel_mid_gpio *priv = gpiochip_get_data(chip);
132	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
133	u32 value;
134	unsigned long flags;
135
136	if (priv->pdev)
137		pm_runtime_get(&priv->pdev->dev);
138
139	spin_lock_irqsave(&priv->lock, flags);
140	value = readl(gpdr);
141	value &= ~BIT(offset % 32);
142	writel(value, gpdr);
143	spin_unlock_irqrestore(&priv->lock, flags);
144
145	if (priv->pdev)
146		pm_runtime_put(&priv->pdev->dev);
147
148	return 0;
149}
150
151static int intel_gpio_direction_output(struct gpio_chip *chip,
152			unsigned offset, int value)
153{
154	struct intel_mid_gpio *priv = gpiochip_get_data(chip);
155	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
156	unsigned long flags;
157
158	intel_gpio_set(chip, offset, value);
159
160	if (priv->pdev)
161		pm_runtime_get(&priv->pdev->dev);
162
163	spin_lock_irqsave(&priv->lock, flags);
164	value = readl(gpdr);
165	value |= BIT(offset % 32);
166	writel(value, gpdr);
167	spin_unlock_irqrestore(&priv->lock, flags);
168
169	if (priv->pdev)
170		pm_runtime_put(&priv->pdev->dev);
171
172	return 0;
173}
174
175static int intel_mid_irq_type(struct irq_data *d, unsigned type)
176{
177	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
178	struct intel_mid_gpio *priv = gpiochip_get_data(gc);
179	u32 gpio = irqd_to_hwirq(d);
180	unsigned long flags;
181	u32 value;
182	void __iomem *grer = gpio_reg(&priv->chip, gpio, GRER);
183	void __iomem *gfer = gpio_reg(&priv->chip, gpio, GFER);
184
185	if (gpio >= priv->chip.ngpio)
186		return -EINVAL;
187
188	if (priv->pdev)
189		pm_runtime_get(&priv->pdev->dev);
190
191	spin_lock_irqsave(&priv->lock, flags);
192	if (type & IRQ_TYPE_EDGE_RISING)
193		value = readl(grer) | BIT(gpio % 32);
194	else
195		value = readl(grer) & (~BIT(gpio % 32));
196	writel(value, grer);
197
198	if (type & IRQ_TYPE_EDGE_FALLING)
199		value = readl(gfer) | BIT(gpio % 32);
200	else
201		value = readl(gfer) & (~BIT(gpio % 32));
202	writel(value, gfer);
203	spin_unlock_irqrestore(&priv->lock, flags);
204
205	if (priv->pdev)
206		pm_runtime_put(&priv->pdev->dev);
207
208	return 0;
209}
210
211static void intel_mid_irq_unmask(struct irq_data *d)
212{
213}
214
215static void intel_mid_irq_mask(struct irq_data *d)
216{
217}
218
219static struct irq_chip intel_mid_irqchip = {
220	.name		= "INTEL_MID-GPIO",
221	.irq_mask	= intel_mid_irq_mask,
222	.irq_unmask	= intel_mid_irq_unmask,
223	.irq_set_type	= intel_mid_irq_type,
224};
225
226static const struct intel_mid_gpio_ddata gpio_lincroft = {
227	.ngpio = 64,
228};
229
230static const struct intel_mid_gpio_ddata gpio_penwell_aon = {
231	.ngpio = 96,
232	.chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE,
233};
234
235static const struct intel_mid_gpio_ddata gpio_penwell_core = {
236	.ngpio = 96,
237	.chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE,
238};
239
240static const struct intel_mid_gpio_ddata gpio_cloverview_aon = {
241	.ngpio = 96,
242	.chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE | INTEL_MID_IRQ_TYPE_LEVEL,
243};
244
245static const struct intel_mid_gpio_ddata gpio_cloverview_core = {
246	.ngpio = 96,
247	.chip_irq_type = INTEL_MID_IRQ_TYPE_EDGE,
248};
249
250static const struct pci_device_id intel_gpio_ids[] = {
251	{
252		/* Lincroft */
253		PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f),
254		.driver_data = (kernel_ulong_t)&gpio_lincroft,
255	},
256	{
257		/* Penwell AON */
258		PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081f),
259		.driver_data = (kernel_ulong_t)&gpio_penwell_aon,
260	},
261	{
262		/* Penwell Core */
263		PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081a),
264		.driver_data = (kernel_ulong_t)&gpio_penwell_core,
265	},
266	{
267		/* Cloverview Aon */
268		PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x08eb),
269		.driver_data = (kernel_ulong_t)&gpio_cloverview_aon,
270	},
271	{
272		/* Cloverview Core */
273		PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x08f7),
274		.driver_data = (kernel_ulong_t)&gpio_cloverview_core,
275	},
276	{ 0 }
277};
278MODULE_DEVICE_TABLE(pci, intel_gpio_ids);
279
280static void intel_mid_irq_handler(struct irq_desc *desc)
281{
282	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
283	struct intel_mid_gpio *priv = gpiochip_get_data(gc);
284	struct irq_data *data = irq_desc_get_irq_data(desc);
285	struct irq_chip *chip = irq_data_get_irq_chip(data);
286	u32 base, gpio, mask;
287	unsigned long pending;
288	void __iomem *gedr;
289
290	/* check GPIO controller to check which pin triggered the interrupt */
291	for (base = 0; base < priv->chip.ngpio; base += 32) {
292		gedr = gpio_reg(&priv->chip, base, GEDR);
293		while ((pending = readl(gedr))) {
294			gpio = __ffs(pending);
295			mask = BIT(gpio);
296			/* Clear before handling so we can't lose an edge */
297			writel(mask, gedr);
298			generic_handle_irq(irq_find_mapping(gc->irq.domain,
299							    base + gpio));
300		}
301	}
302
303	chip->irq_eoi(data);
304}
305
306static void intel_mid_irq_init_hw(struct intel_mid_gpio *priv)
307{
308	void __iomem *reg;
309	unsigned base;
310
311	for (base = 0; base < priv->chip.ngpio; base += 32) {
312		/* Clear the rising-edge detect register */
313		reg = gpio_reg(&priv->chip, base, GRER);
314		writel(0, reg);
315		/* Clear the falling-edge detect register */
316		reg = gpio_reg(&priv->chip, base, GFER);
317		writel(0, reg);
318		/* Clear the edge detect status register */
319		reg = gpio_reg(&priv->chip, base, GEDR);
320		writel(~0, reg);
321	}
322}
323
324static int __maybe_unused intel_gpio_runtime_idle(struct device *dev)
325{
326	int err = pm_schedule_suspend(dev, 500);
327	return err ?: -EBUSY;
328}
329
330static const struct dev_pm_ops intel_gpio_pm_ops = {
331	SET_RUNTIME_PM_OPS(NULL, NULL, intel_gpio_runtime_idle)
332};
333
334static int intel_gpio_probe(struct pci_dev *pdev,
335			  const struct pci_device_id *id)
336{
337	void __iomem *base;
338	struct intel_mid_gpio *priv;
339	u32 gpio_base;
340	u32 irq_base;
341	int retval;
342	struct intel_mid_gpio_ddata *ddata =
343				(struct intel_mid_gpio_ddata *)id->driver_data;
344
345	retval = pcim_enable_device(pdev);
346	if (retval)
347		return retval;
348
349	retval = pcim_iomap_regions(pdev, 1 << 0 | 1 << 1, pci_name(pdev));
350	if (retval) {
351		dev_err(&pdev->dev, "I/O memory mapping error\n");
352		return retval;
353	}
354
355	base = pcim_iomap_table(pdev)[1];
356
357	irq_base = readl(base);
358	gpio_base = readl(sizeof(u32) + base);
359
360	/* release the IO mapping, since we already get the info from bar1 */
361	pcim_iounmap_regions(pdev, 1 << 1);
362
363	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
364	if (!priv)
365		return -ENOMEM;
366
367	priv->reg_base = pcim_iomap_table(pdev)[0];
368	priv->chip.label = dev_name(&pdev->dev);
369	priv->chip.parent = &pdev->dev;
370	priv->chip.request = intel_gpio_request;
371	priv->chip.direction_input = intel_gpio_direction_input;
372	priv->chip.direction_output = intel_gpio_direction_output;
373	priv->chip.get = intel_gpio_get;
374	priv->chip.set = intel_gpio_set;
375	priv->chip.base = gpio_base;
376	priv->chip.ngpio = ddata->ngpio;
377	priv->chip.can_sleep = false;
378	priv->pdev = pdev;
379
380	spin_lock_init(&priv->lock);
381
382	pci_set_drvdata(pdev, priv);
383	retval = devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
384	if (retval) {
385		dev_err(&pdev->dev, "gpiochip_add error %d\n", retval);
386		return retval;
387	}
388
389	retval = gpiochip_irqchip_add(&priv->chip,
390				      &intel_mid_irqchip,
391				      irq_base,
392				      handle_simple_irq,
393				      IRQ_TYPE_NONE);
394	if (retval) {
395		dev_err(&pdev->dev,
396			"could not connect irqchip to gpiochip\n");
397		return retval;
398	}
399
400	intel_mid_irq_init_hw(priv);
401
402	gpiochip_set_chained_irqchip(&priv->chip,
403				     &intel_mid_irqchip,
404				     pdev->irq,
405				     intel_mid_irq_handler);
406
407	pm_runtime_put_noidle(&pdev->dev);
408	pm_runtime_allow(&pdev->dev);
409
410	return 0;
411}
412
413static struct pci_driver intel_gpio_driver = {
414	.name		= "intel_mid_gpio",
415	.id_table	= intel_gpio_ids,
416	.probe		= intel_gpio_probe,
417	.driver		= {
418		.pm	= &intel_gpio_pm_ops,
419	},
420};
421
422builtin_pci_driver(intel_gpio_driver);