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v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2//
  3// IXP4 GPIO driver
  4// Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
  5//
  6// based on previous work and know-how from:
  7// Deepak Saxena <dsaxena@plexity.net>
  8
  9#include <linux/bitops.h>
 10#include <linux/gpio/driver.h>
 11#include <linux/io.h>
 12#include <linux/irq.h>
 13#include <linux/irqdomain.h>
 14#include <linux/irqchip.h>
 15#include <linux/of_irq.h>
 16#include <linux/platform_device.h>
 17#include <linux/property.h>
 
 
 
 
 18
 19#define IXP4XX_REG_GPOUT	0x00
 20#define IXP4XX_REG_GPOE		0x04
 21#define IXP4XX_REG_GPIN		0x08
 22#define IXP4XX_REG_GPIS		0x0C
 23#define IXP4XX_REG_GPIT1	0x10
 24#define IXP4XX_REG_GPIT2	0x14
 25#define IXP4XX_REG_GPCLK	0x18
 26#define IXP4XX_REG_GPDBSEL	0x1C
 27
 28/*
 29 * The hardware uses 3 bits to indicate interrupt "style".
 30 * we clear and set these three bits accordingly. The lower 24
 31 * bits in two registers (GPIT1 and GPIT2) are used to set up
 32 * the style for 8 lines each for a total of 16 GPIO lines.
 33 */
 34#define IXP4XX_GPIO_STYLE_ACTIVE_HIGH	0x0
 35#define IXP4XX_GPIO_STYLE_ACTIVE_LOW	0x1
 36#define IXP4XX_GPIO_STYLE_RISING_EDGE	0x2
 37#define IXP4XX_GPIO_STYLE_FALLING_EDGE	0x3
 38#define IXP4XX_GPIO_STYLE_TRANSITIONAL	0x4
 39#define IXP4XX_GPIO_STYLE_MASK		GENMASK(2, 0)
 40#define IXP4XX_GPIO_STYLE_SIZE		3
 41
 42/*
 43 * Clock output control register defines.
 44 */
 45#define IXP4XX_GPCLK_CLK0DC_SHIFT	0
 46#define IXP4XX_GPCLK_CLK0TC_SHIFT	4
 47#define IXP4XX_GPCLK_CLK0_MASK		GENMASK(7, 0)
 48#define IXP4XX_GPCLK_MUX14		BIT(8)
 49#define IXP4XX_GPCLK_CLK1DC_SHIFT	16
 50#define IXP4XX_GPCLK_CLK1TC_SHIFT	20
 51#define IXP4XX_GPCLK_CLK1_MASK		GENMASK(23, 16)
 52#define IXP4XX_GPCLK_MUX15		BIT(24)
 53
 54/**
 55 * struct ixp4xx_gpio - IXP4 GPIO state container
 56 * @dev: containing device for this instance
 
 57 * @gc: gpiochip for this instance
 58 * @base: remapped I/O-memory base
 59 * @irq_edge: Each bit represents an IRQ: 1: edge-triggered,
 60 * 0: level triggered
 61 */
 62struct ixp4xx_gpio {
 63	struct gpio_chip gc;
 64	struct device *dev;
 
 
 65	void __iomem *base;
 66	unsigned long long irq_edge;
 67};
 68
 69static void ixp4xx_gpio_irq_ack(struct irq_data *d)
 70{
 71	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 72	struct ixp4xx_gpio *g = gpiochip_get_data(gc);
 73
 74	__raw_writel(BIT(d->hwirq), g->base + IXP4XX_REG_GPIS);
 75}
 76
 77static void ixp4xx_gpio_mask_irq(struct irq_data *d)
 78{
 79	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 80
 81	irq_chip_mask_parent(d);
 82	gpiochip_disable_irq(gc, d->hwirq);
 83}
 84
 85static void ixp4xx_gpio_irq_unmask(struct irq_data *d)
 86{
 87	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 88	struct ixp4xx_gpio *g = gpiochip_get_data(gc);
 89
 90	/* ACK when unmasking if not edge-triggered */
 91	if (!(g->irq_edge & BIT(d->hwirq)))
 92		ixp4xx_gpio_irq_ack(d);
 93
 94	gpiochip_enable_irq(gc, d->hwirq);
 95	irq_chip_unmask_parent(d);
 96}
 97
 98static int ixp4xx_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 99{
100	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
101	struct ixp4xx_gpio *g = gpiochip_get_data(gc);
102	int line = d->hwirq;
103	unsigned long flags;
104	u32 int_style;
105	u32 int_reg;
106	u32 val;
107
108	switch (type) {
109	case IRQ_TYPE_EDGE_BOTH:
110		irq_set_handler_locked(d, handle_edge_irq);
111		int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL;
112		g->irq_edge |= BIT(d->hwirq);
113		break;
114	case IRQ_TYPE_EDGE_RISING:
115		irq_set_handler_locked(d, handle_edge_irq);
116		int_style = IXP4XX_GPIO_STYLE_RISING_EDGE;
117		g->irq_edge |= BIT(d->hwirq);
118		break;
119	case IRQ_TYPE_EDGE_FALLING:
120		irq_set_handler_locked(d, handle_edge_irq);
121		int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE;
122		g->irq_edge |= BIT(d->hwirq);
123		break;
124	case IRQ_TYPE_LEVEL_HIGH:
125		irq_set_handler_locked(d, handle_level_irq);
126		int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH;
127		g->irq_edge &= ~BIT(d->hwirq);
128		break;
129	case IRQ_TYPE_LEVEL_LOW:
130		irq_set_handler_locked(d, handle_level_irq);
131		int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW;
132		g->irq_edge &= ~BIT(d->hwirq);
133		break;
134	default:
135		return -EINVAL;
136	}
137
138	if (line >= 8) {
139		/* pins 8-15 */
140		line -= 8;
141		int_reg = IXP4XX_REG_GPIT2;
142	} else {
143		/* pins 0-7 */
144		int_reg = IXP4XX_REG_GPIT1;
145	}
146
147	raw_spin_lock_irqsave(&g->gc.bgpio_lock, flags);
148
149	/* Clear the style for the appropriate pin */
150	val = __raw_readl(g->base + int_reg);
151	val &= ~(IXP4XX_GPIO_STYLE_MASK << (line * IXP4XX_GPIO_STYLE_SIZE));
152	__raw_writel(val, g->base + int_reg);
153
154	__raw_writel(BIT(line), g->base + IXP4XX_REG_GPIS);
155
156	/* Set the new style */
157	val = __raw_readl(g->base + int_reg);
158	val |= (int_style << (line * IXP4XX_GPIO_STYLE_SIZE));
159	__raw_writel(val, g->base + int_reg);
160
161	/* Force-configure this line as an input */
162	val = __raw_readl(g->base + IXP4XX_REG_GPOE);
163	val |= BIT(d->hwirq);
164	__raw_writel(val, g->base + IXP4XX_REG_GPOE);
165
166	raw_spin_unlock_irqrestore(&g->gc.bgpio_lock, flags);
167
168	/* This parent only accept level high (asserted) */
169	return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
170}
171
172static const struct irq_chip ixp4xx_gpio_irqchip = {
173	.name = "IXP4GPIO",
174	.irq_ack = ixp4xx_gpio_irq_ack,
175	.irq_mask = ixp4xx_gpio_mask_irq,
176	.irq_unmask = ixp4xx_gpio_irq_unmask,
177	.irq_set_type = ixp4xx_gpio_irq_set_type,
178	.flags = IRQCHIP_IMMUTABLE,
179	GPIOCHIP_IRQ_RESOURCE_HELPERS,
180};
181
182static int ixp4xx_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
183					     unsigned int child,
184					     unsigned int child_type,
185					     unsigned int *parent,
186					     unsigned int *parent_type)
187{
188	/* All these interrupts are level high in the CPU */
189	*parent_type = IRQ_TYPE_LEVEL_HIGH;
190
191	/* GPIO lines 0..12 have dedicated IRQs */
192	if (child == 0) {
193		*parent = 6;
194		return 0;
195	}
196	if (child == 1) {
197		*parent = 7;
198		return 0;
199	}
200	if (child >= 2 && child <= 12) {
201		*parent = child + 17;
202		return 0;
203	}
204	return -EINVAL;
205}
206
207static int ixp4xx_gpio_probe(struct platform_device *pdev)
208{
209	unsigned long flags;
210	struct device *dev = &pdev->dev;
211	struct device_node *np = dev->of_node;
212	struct irq_domain *parent;
 
213	struct ixp4xx_gpio *g;
214	struct gpio_irq_chip *girq;
215	struct device_node *irq_parent;
216	bool clk_14, clk_15;
217	u32 val;
218	int ret;
219
220	g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
221	if (!g)
222		return -ENOMEM;
223	g->dev = dev;
224
225	g->base = devm_platform_ioremap_resource(pdev, 0);
 
226	if (IS_ERR(g->base))
227		return PTR_ERR(g->base);
228
229	irq_parent = of_irq_find_parent(np);
230	if (!irq_parent) {
231		dev_err(dev, "no IRQ parent node\n");
232		return -ENODEV;
233	}
234	parent = irq_find_host(irq_parent);
235	if (!parent) {
236		dev_err(dev, "no IRQ parent domain\n");
237		return -ENODEV;
238	}
239
240	/*
241	 * If either clock output is enabled explicitly in the device tree
242	 * we take full control of the clock by masking off all bits for
243	 * the clock control and selectively enabling them. Otherwise
244	 * we leave the hardware default settings.
245	 *
246	 * Enable clock outputs with default timings of requested clock.
247	 * If you need control over TC and DC, add these to the device
248	 * tree bindings and use them here.
249	 */
250	clk_14 = of_property_read_bool(np, "intel,ixp4xx-gpio14-clkout");
251	clk_15 = of_property_read_bool(np, "intel,ixp4xx-gpio15-clkout");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
252
253	/*
254	 * Make sure GPIO 14 and 15 are NOT used as clocks but GPIO on
255	 * specific machines.
256	 */
257	if (of_machine_is_compatible("dlink,dsm-g600-a") ||
258	    of_machine_is_compatible("iom,nas-100d"))
259		val = 0;
260	else {
261		val = __raw_readl(g->base + IXP4XX_REG_GPCLK);
262
263		if (clk_14 || clk_15) {
264			val &= ~(IXP4XX_GPCLK_MUX14 | IXP4XX_GPCLK_MUX15);
265			val &= ~IXP4XX_GPCLK_CLK0_MASK;
266			val &= ~IXP4XX_GPCLK_CLK1_MASK;
267			if (clk_14) {
268				/* IXP4XX_GPCLK_CLK0DC implicit low */
269				val |= (1 << IXP4XX_GPCLK_CLK0TC_SHIFT);
270				val |= IXP4XX_GPCLK_MUX14;
271			}
272
273			if (clk_15) {
274				/* IXP4XX_GPCLK_CLK1DC implicit low */
275				val |= (1 << IXP4XX_GPCLK_CLK1TC_SHIFT);
276				val |= IXP4XX_GPCLK_MUX15;
277			}
278		}
279	}
280
281	__raw_writel(val, g->base + IXP4XX_REG_GPCLK);
282
283	/*
284	 * This is a very special big-endian ARM issue: when the IXP4xx is
285	 * run in big endian mode, all registers in the machine are switched
286	 * around to the CPU-native endianness. As you see mostly in the
287	 * driver we use __raw_readl()/__raw_writel() to access the registers
288	 * in the appropriate order. With the GPIO library we need to specify
289	 * byte order explicitly, so this flag needs to be set when compiling
290	 * for big endian.
291	 */
292#if defined(CONFIG_CPU_BIG_ENDIAN)
293	flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER;
294#else
295	flags = 0;
296#endif
297
298	/* Populate and register gpio chip */
299	ret = bgpio_init(&g->gc, dev, 4,
300			 g->base + IXP4XX_REG_GPIN,
301			 g->base + IXP4XX_REG_GPOUT,
302			 NULL,
303			 NULL,
304			 g->base + IXP4XX_REG_GPOE,
305			 flags);
306	if (ret) {
307		dev_err(dev, "unable to init generic GPIO\n");
308		return ret;
309	}
310	g->gc.ngpio = 16;
311	g->gc.label = "IXP4XX_GPIO_CHIP";
312	/*
313	 * TODO: when we have migrated to device tree and all GPIOs
314	 * are fetched using phandles, set this to -1 to get rid of
315	 * the fixed gpiochip base.
316	 */
317	g->gc.base = 0;
318	g->gc.parent = &pdev->dev;
319	g->gc.owner = THIS_MODULE;
320
321	girq = &g->gc.irq;
322	gpio_irq_chip_set_chip(girq, &ixp4xx_gpio_irqchip);
323	girq->fwnode = dev_fwnode(dev);
324	girq->parent_domain = parent;
325	girq->child_to_parent_hwirq = ixp4xx_gpio_child_to_parent_hwirq;
326	girq->handler = handle_bad_irq;
327	girq->default_type = IRQ_TYPE_NONE;
328
329	ret = devm_gpiochip_add_data(dev, &g->gc, g);
330	if (ret) {
331		dev_err(dev, "failed to add SoC gpiochip\n");
332		return ret;
333	}
334
335	platform_set_drvdata(pdev, g);
336	dev_info(dev, "IXP4 GPIO registered\n");
337
338	return 0;
339}
340
341static const struct of_device_id ixp4xx_gpio_of_match[] = {
342	{
343		.compatible = "intel,ixp4xx-gpio",
344	},
345	{},
346};
347
348
349static struct platform_driver ixp4xx_gpio_driver = {
350	.driver = {
351		.name		= "ixp4xx-gpio",
352		.of_match_table = ixp4xx_gpio_of_match,
353	},
354	.probe = ixp4xx_gpio_probe,
355};
356builtin_platform_driver(ixp4xx_gpio_driver);
v5.14.15
  1// SPDX-License-Identifier: GPL-2.0
  2//
  3// IXP4 GPIO driver
  4// Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
  5//
  6// based on previous work and know-how from:
  7// Deepak Saxena <dsaxena@plexity.net>
  8
 
  9#include <linux/gpio/driver.h>
 10#include <linux/io.h>
 11#include <linux/irq.h>
 12#include <linux/irqdomain.h>
 13#include <linux/irqchip.h>
 14#include <linux/of_irq.h>
 15#include <linux/platform_device.h>
 16#include <linux/bitops.h>
 17/* Include that go away with DT transition */
 18#include <linux/irqchip/irq-ixp4xx.h>
 19
 20#include <asm/mach-types.h>
 21
 22#define IXP4XX_REG_GPOUT	0x00
 23#define IXP4XX_REG_GPOE		0x04
 24#define IXP4XX_REG_GPIN		0x08
 25#define IXP4XX_REG_GPIS		0x0C
 26#define IXP4XX_REG_GPIT1	0x10
 27#define IXP4XX_REG_GPIT2	0x14
 28#define IXP4XX_REG_GPCLK	0x18
 29#define IXP4XX_REG_GPDBSEL	0x1C
 30
 31/*
 32 * The hardware uses 3 bits to indicate interrupt "style".
 33 * we clear and set these three bits accordingly. The lower 24
 34 * bits in two registers (GPIT1 and GPIT2) are used to set up
 35 * the style for 8 lines each for a total of 16 GPIO lines.
 36 */
 37#define IXP4XX_GPIO_STYLE_ACTIVE_HIGH	0x0
 38#define IXP4XX_GPIO_STYLE_ACTIVE_LOW	0x1
 39#define IXP4XX_GPIO_STYLE_RISING_EDGE	0x2
 40#define IXP4XX_GPIO_STYLE_FALLING_EDGE	0x3
 41#define IXP4XX_GPIO_STYLE_TRANSITIONAL	0x4
 42#define IXP4XX_GPIO_STYLE_MASK		GENMASK(2, 0)
 43#define IXP4XX_GPIO_STYLE_SIZE		3
 44
 
 
 
 
 
 
 
 
 
 
 
 
 45/**
 46 * struct ixp4xx_gpio - IXP4 GPIO state container
 47 * @dev: containing device for this instance
 48 * @fwnode: the fwnode for this GPIO chip
 49 * @gc: gpiochip for this instance
 50 * @base: remapped I/O-memory base
 51 * @irq_edge: Each bit represents an IRQ: 1: edge-triggered,
 52 * 0: level triggered
 53 */
 54struct ixp4xx_gpio {
 
 55	struct device *dev;
 56	struct fwnode_handle *fwnode;
 57	struct gpio_chip gc;
 58	void __iomem *base;
 59	unsigned long long irq_edge;
 60};
 61
 62static void ixp4xx_gpio_irq_ack(struct irq_data *d)
 63{
 64	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 65	struct ixp4xx_gpio *g = gpiochip_get_data(gc);
 66
 67	__raw_writel(BIT(d->hwirq), g->base + IXP4XX_REG_GPIS);
 68}
 69
 
 
 
 
 
 
 
 
 70static void ixp4xx_gpio_irq_unmask(struct irq_data *d)
 71{
 72	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 73	struct ixp4xx_gpio *g = gpiochip_get_data(gc);
 74
 75	/* ACK when unmasking if not edge-triggered */
 76	if (!(g->irq_edge & BIT(d->hwirq)))
 77		ixp4xx_gpio_irq_ack(d);
 78
 
 79	irq_chip_unmask_parent(d);
 80}
 81
 82static int ixp4xx_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 83{
 84	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 85	struct ixp4xx_gpio *g = gpiochip_get_data(gc);
 86	int line = d->hwirq;
 87	unsigned long flags;
 88	u32 int_style;
 89	u32 int_reg;
 90	u32 val;
 91
 92	switch (type) {
 93	case IRQ_TYPE_EDGE_BOTH:
 94		irq_set_handler_locked(d, handle_edge_irq);
 95		int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL;
 96		g->irq_edge |= BIT(d->hwirq);
 97		break;
 98	case IRQ_TYPE_EDGE_RISING:
 99		irq_set_handler_locked(d, handle_edge_irq);
100		int_style = IXP4XX_GPIO_STYLE_RISING_EDGE;
101		g->irq_edge |= BIT(d->hwirq);
102		break;
103	case IRQ_TYPE_EDGE_FALLING:
104		irq_set_handler_locked(d, handle_edge_irq);
105		int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE;
106		g->irq_edge |= BIT(d->hwirq);
107		break;
108	case IRQ_TYPE_LEVEL_HIGH:
109		irq_set_handler_locked(d, handle_level_irq);
110		int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH;
111		g->irq_edge &= ~BIT(d->hwirq);
112		break;
113	case IRQ_TYPE_LEVEL_LOW:
114		irq_set_handler_locked(d, handle_level_irq);
115		int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW;
116		g->irq_edge &= ~BIT(d->hwirq);
117		break;
118	default:
119		return -EINVAL;
120	}
121
122	if (line >= 8) {
123		/* pins 8-15 */
124		line -= 8;
125		int_reg = IXP4XX_REG_GPIT2;
126	} else {
127		/* pins 0-7 */
128		int_reg = IXP4XX_REG_GPIT1;
129	}
130
131	spin_lock_irqsave(&g->gc.bgpio_lock, flags);
132
133	/* Clear the style for the appropriate pin */
134	val = __raw_readl(g->base + int_reg);
135	val &= ~(IXP4XX_GPIO_STYLE_MASK << (line * IXP4XX_GPIO_STYLE_SIZE));
136	__raw_writel(val, g->base + int_reg);
137
138	__raw_writel(BIT(line), g->base + IXP4XX_REG_GPIS);
139
140	/* Set the new style */
141	val = __raw_readl(g->base + int_reg);
142	val |= (int_style << (line * IXP4XX_GPIO_STYLE_SIZE));
143	__raw_writel(val, g->base + int_reg);
144
145	/* Force-configure this line as an input */
146	val = __raw_readl(g->base + IXP4XX_REG_GPOE);
147	val |= BIT(d->hwirq);
148	__raw_writel(val, g->base + IXP4XX_REG_GPOE);
149
150	spin_unlock_irqrestore(&g->gc.bgpio_lock, flags);
151
152	/* This parent only accept level high (asserted) */
153	return irq_chip_set_type_parent(d, IRQ_TYPE_LEVEL_HIGH);
154}
155
156static struct irq_chip ixp4xx_gpio_irqchip = {
157	.name = "IXP4GPIO",
158	.irq_ack = ixp4xx_gpio_irq_ack,
159	.irq_mask = irq_chip_mask_parent,
160	.irq_unmask = ixp4xx_gpio_irq_unmask,
161	.irq_set_type = ixp4xx_gpio_irq_set_type,
 
 
162};
163
164static int ixp4xx_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
165					     unsigned int child,
166					     unsigned int child_type,
167					     unsigned int *parent,
168					     unsigned int *parent_type)
169{
170	/* All these interrupts are level high in the CPU */
171	*parent_type = IRQ_TYPE_LEVEL_HIGH;
172
173	/* GPIO lines 0..12 have dedicated IRQs */
174	if (child == 0) {
175		*parent = 6;
176		return 0;
177	}
178	if (child == 1) {
179		*parent = 7;
180		return 0;
181	}
182	if (child >= 2 && child <= 12) {
183		*parent = child + 17;
184		return 0;
185	}
186	return -EINVAL;
187}
188
189static int ixp4xx_gpio_probe(struct platform_device *pdev)
190{
191	unsigned long flags;
192	struct device *dev = &pdev->dev;
193	struct device_node *np = dev->of_node;
194	struct irq_domain *parent;
195	struct resource *res;
196	struct ixp4xx_gpio *g;
197	struct gpio_irq_chip *girq;
 
 
 
198	int ret;
199
200	g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
201	if (!g)
202		return -ENOMEM;
203	g->dev = dev;
204
205	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
206	g->base = devm_ioremap_resource(dev, res);
207	if (IS_ERR(g->base))
208		return PTR_ERR(g->base);
209
 
 
 
 
 
 
 
 
 
 
 
210	/*
211	 * When we convert to device tree we will simply look up the
212	 * parent irqdomain using irq_find_host(parent) as parent comes
213	 * from IRQCHIP_DECLARE(), then use of_node_to_fwnode() to get
214	 * the fwnode. For now we need this boardfile style code.
 
 
 
 
215	 */
216	if (np) {
217		struct device_node *irq_parent;
218
219		irq_parent = of_irq_find_parent(np);
220		if (!irq_parent) {
221			dev_err(dev, "no IRQ parent node\n");
222			return -ENODEV;
223		}
224		parent = irq_find_host(irq_parent);
225		if (!parent) {
226			dev_err(dev, "no IRQ parent domain\n");
227			return -ENODEV;
228		}
229		g->fwnode = of_node_to_fwnode(np);
230	} else {
231		parent = ixp4xx_get_irq_domain();
232		g->fwnode = irq_domain_alloc_fwnode(&res->start);
233		if (!g->fwnode) {
234			dev_err(dev, "no domain base\n");
235			return -ENODEV;
236		}
237	}
238
239	/*
240	 * Make sure GPIO 14 and 15 are NOT used as clocks but GPIO on
241	 * specific machines.
242	 */
243	if (machine_is_dsmg600() || machine_is_nas100d())
244		__raw_writel(0x0, g->base + IXP4XX_REG_GPCLK);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
245
246	/*
247	 * This is a very special big-endian ARM issue: when the IXP4xx is
248	 * run in big endian mode, all registers in the machine are switched
249	 * around to the CPU-native endianness. As you see mostly in the
250	 * driver we use __raw_readl()/__raw_writel() to access the registers
251	 * in the appropriate order. With the GPIO library we need to specify
252	 * byte order explicitly, so this flag needs to be set when compiling
253	 * for big endian.
254	 */
255#if defined(CONFIG_CPU_BIG_ENDIAN)
256	flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER;
257#else
258	flags = 0;
259#endif
260
261	/* Populate and register gpio chip */
262	ret = bgpio_init(&g->gc, dev, 4,
263			 g->base + IXP4XX_REG_GPIN,
264			 g->base + IXP4XX_REG_GPOUT,
265			 NULL,
266			 NULL,
267			 g->base + IXP4XX_REG_GPOE,
268			 flags);
269	if (ret) {
270		dev_err(dev, "unable to init generic GPIO\n");
271		return ret;
272	}
273	g->gc.ngpio = 16;
274	g->gc.label = "IXP4XX_GPIO_CHIP";
275	/*
276	 * TODO: when we have migrated to device tree and all GPIOs
277	 * are fetched using phandles, set this to -1 to get rid of
278	 * the fixed gpiochip base.
279	 */
280	g->gc.base = 0;
281	g->gc.parent = &pdev->dev;
282	g->gc.owner = THIS_MODULE;
283
284	girq = &g->gc.irq;
285	girq->chip = &ixp4xx_gpio_irqchip;
286	girq->fwnode = g->fwnode;
287	girq->parent_domain = parent;
288	girq->child_to_parent_hwirq = ixp4xx_gpio_child_to_parent_hwirq;
289	girq->handler = handle_bad_irq;
290	girq->default_type = IRQ_TYPE_NONE;
291
292	ret = devm_gpiochip_add_data(dev, &g->gc, g);
293	if (ret) {
294		dev_err(dev, "failed to add SoC gpiochip\n");
295		return ret;
296	}
297
298	platform_set_drvdata(pdev, g);
299	dev_info(dev, "IXP4 GPIO registered\n");
300
301	return 0;
302}
303
304static const struct of_device_id ixp4xx_gpio_of_match[] = {
305	{
306		.compatible = "intel,ixp4xx-gpio",
307	},
308	{},
309};
310
311
312static struct platform_driver ixp4xx_gpio_driver = {
313	.driver = {
314		.name		= "ixp4xx-gpio",
315		.of_match_table = of_match_ptr(ixp4xx_gpio_of_match),
316	},
317	.probe = ixp4xx_gpio_probe,
318};
319builtin_platform_driver(ixp4xx_gpio_driver);