1 /* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
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.
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.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 #define pr_fmt(fmt) "%s: " fmt, __func__
20 #include <linux/bitmap.h>
21 #include <linux/bitops.h>
22 #include <linux/err.h>
23 #include <linux/gpio.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
27 #include <linux/irqchip/chained_irq.h>
28 #include <linux/irq.h>
29 #include <linux/irqdomain.h>
30 #include <linux/module.h>
31 #include <linux/of_address.h>
32 #include <linux/platform_device.h>
33 #include <linux/spinlock.h>
34 #include <linux/slab.h>
36 #define MAX_NR_GPIO 300
38 /* Bits of interest in the GPIO_IN_OUT register.
45 /* Bits of interest in the GPIO_INTR_STATUS register.
51 /* Bits of interest in the GPIO_CFG register.
57 /* Bits of interest in the GPIO_INTR_CFG register.
58 * When a GPIO triggers, two separate decisions are made, controlled
59 * by two separate flags.
61 * - First, INTR_RAW_STATUS_EN controls whether or not the GPIO_INTR_STATUS
62 * register for that GPIO will be updated to reflect the triggering of that
63 * gpio. If this bit is 0, this register will not be updated.
64 * - Second, INTR_ENABLE controls whether an interrupt is triggered.
66 * If INTR_ENABLE is set and INTR_RAW_STATUS_EN is NOT set, an interrupt
67 * can be triggered but the status register will not reflect it.
73 INTR_RAW_STATUS_EN = 3,
76 /* Codes of interest in GPIO_INTR_CFG_SU.
79 TARGET_PROC_SCORPION = 4,
84 * struct msm_gpio_dev: the MSM8660 SoC GPIO device structure
86 * @enabled_irqs: a bitmap used to optimize the summary-irq handler. By
87 * keeping track of which gpios are unmasked as irq sources, we avoid
88 * having to do readl calls on hundreds of iomapped registers each time
89 * the summary interrupt fires in order to locate the active interrupts.
91 * @wake_irqs: a bitmap for tracking which interrupt lines are enabled
92 * as wakeup sources. When the device is suspended, interrupts which are
93 * not wakeup sources are disabled.
95 * @dual_edge_irqs: a bitmap used to track which irqs are configured
96 * as dual-edge, as this is not supported by the hardware and requires
97 * some special handling in the driver.
100 struct gpio_chip gpio_chip;
101 DECLARE_BITMAP(enabled_irqs, MAX_NR_GPIO);
102 DECLARE_BITMAP(wake_irqs, MAX_NR_GPIO);
103 DECLARE_BITMAP(dual_edge_irqs, MAX_NR_GPIO);
104 struct irq_domain *domain;
106 void __iomem *msm_tlmm_base;
109 static struct msm_gpio_dev msm_gpio;
111 #define GPIO_INTR_CFG_SU(gpio) (msm_gpio.msm_tlmm_base + 0x0400 + \
113 #define GPIO_CONFIG(gpio) (msm_gpio.msm_tlmm_base + 0x1000 + \
115 #define GPIO_IN_OUT(gpio) (msm_gpio.msm_tlmm_base + 0x1004 + \
117 #define GPIO_INTR_CFG(gpio) (msm_gpio.msm_tlmm_base + 0x1008 + \
119 #define GPIO_INTR_STATUS(gpio) (msm_gpio.msm_tlmm_base + 0x100c + \
122 static DEFINE_SPINLOCK(tlmm_lock);
124 static inline struct msm_gpio_dev *to_msm_gpio_dev(struct gpio_chip *chip)
126 return container_of(chip, struct msm_gpio_dev, gpio_chip);
129 static inline void set_gpio_bits(unsigned n, void __iomem *reg)
131 writel(readl(reg) | n, reg);
134 static inline void clear_gpio_bits(unsigned n, void __iomem *reg)
136 writel(readl(reg) & ~n, reg);
139 static int msm_gpio_get(struct gpio_chip *chip, unsigned offset)
141 return readl(GPIO_IN_OUT(offset)) & BIT(GPIO_IN);
144 static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
146 writel(val ? BIT(GPIO_OUT) : 0, GPIO_IN_OUT(offset));
149 static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
151 unsigned long irq_flags;
153 spin_lock_irqsave(&tlmm_lock, irq_flags);
154 clear_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));
155 spin_unlock_irqrestore(&tlmm_lock, irq_flags);
159 static int msm_gpio_direction_output(struct gpio_chip *chip,
163 unsigned long irq_flags;
165 spin_lock_irqsave(&tlmm_lock, irq_flags);
166 msm_gpio_set(chip, offset, val);
167 set_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));
168 spin_unlock_irqrestore(&tlmm_lock, irq_flags);
172 static int msm_gpio_request(struct gpio_chip *chip, unsigned offset)
177 static void msm_gpio_free(struct gpio_chip *chip, unsigned offset)
182 static int msm_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
184 struct msm_gpio_dev *g_dev = to_msm_gpio_dev(chip);
185 struct irq_domain *domain = g_dev->domain;
187 return irq_create_mapping(domain, offset);
190 /* For dual-edge interrupts in software, since the hardware has no
193 * At appropriate moments, this function may be called to flip the polarity
194 * settings of both-edge irq lines to try and catch the next edge.
196 * The attempt is considered successful if:
197 * - the status bit goes high, indicating that an edge was caught, or
198 * - the input value of the gpio doesn't change during the attempt.
199 * If the value changes twice during the process, that would cause the first
200 * test to fail but would force the second, as two opposite
201 * transitions would cause a detection no matter the polarity setting.
203 * The do-loop tries to sledge-hammer closed the timing hole between
204 * the initial value-read and the polarity-write - if the line value changes
205 * during that window, an interrupt is lost, the new polarity setting is
206 * incorrect, and the first success test will fail, causing a retry.
208 * Algorithm comes from Google's msmgpio driver, see mach-msm/gpio.c.
210 static void msm_gpio_update_dual_edge_pos(unsigned gpio)
212 int loop_limit = 100;
213 unsigned val, val2, intstat;
216 val = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN);
218 clear_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio));
220 set_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio));
221 val2 = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN);
222 intstat = readl(GPIO_INTR_STATUS(gpio)) & BIT(INTR_STATUS);
223 if (intstat || val == val2)
225 } while (loop_limit-- > 0);
226 pr_err("%s: dual-edge irq failed to stabilize, "
227 "interrupts dropped. %#08x != %#08x\n",
228 __func__, val, val2);
231 static void msm_gpio_irq_ack(struct irq_data *d)
235 writel(BIT(INTR_STATUS), GPIO_INTR_STATUS(gpio));
236 if (test_bit(gpio, msm_gpio.dual_edge_irqs))
237 msm_gpio_update_dual_edge_pos(gpio);
240 static void msm_gpio_irq_mask(struct irq_data *d)
242 unsigned long irq_flags;
245 spin_lock_irqsave(&tlmm_lock, irq_flags);
246 writel(TARGET_PROC_NONE, GPIO_INTR_CFG_SU(gpio));
247 clear_gpio_bits(BIT(INTR_RAW_STATUS_EN) | BIT(INTR_ENABLE), GPIO_INTR_CFG(gpio));
248 __clear_bit(gpio, msm_gpio.enabled_irqs);
249 spin_unlock_irqrestore(&tlmm_lock, irq_flags);
252 static void msm_gpio_irq_unmask(struct irq_data *d)
254 unsigned long irq_flags;
257 spin_lock_irqsave(&tlmm_lock, irq_flags);
258 __set_bit(gpio, msm_gpio.enabled_irqs);
259 set_gpio_bits(BIT(INTR_RAW_STATUS_EN) | BIT(INTR_ENABLE), GPIO_INTR_CFG(gpio));
260 writel(TARGET_PROC_SCORPION, GPIO_INTR_CFG_SU(gpio));
261 spin_unlock_irqrestore(&tlmm_lock, irq_flags);
264 static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int flow_type)
266 unsigned long irq_flags;
270 spin_lock_irqsave(&tlmm_lock, irq_flags);
272 bits = readl(GPIO_INTR_CFG(gpio));
274 if (flow_type & IRQ_TYPE_EDGE_BOTH) {
275 bits |= BIT(INTR_DECT_CTL);
276 irq_set_handler_locked(d, handle_edge_irq);
277 if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
278 __set_bit(gpio, msm_gpio.dual_edge_irqs);
280 __clear_bit(gpio, msm_gpio.dual_edge_irqs);
282 bits &= ~BIT(INTR_DECT_CTL);
283 irq_set_handler_locked(d, handle_level_irq);
284 __clear_bit(gpio, msm_gpio.dual_edge_irqs);
287 if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))
288 bits |= BIT(INTR_POL_CTL);
290 bits &= ~BIT(INTR_POL_CTL);
292 writel(bits, GPIO_INTR_CFG(gpio));
294 if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
295 msm_gpio_update_dual_edge_pos(gpio);
297 spin_unlock_irqrestore(&tlmm_lock, irq_flags);
303 * When the summary IRQ is raised, any number of GPIO lines may be high.
304 * It is the job of the summary handler to find all those GPIO lines
305 * which have been set as summary IRQ lines and which are triggered,
306 * and to call their interrupt handlers.
308 static void msm_summary_irq_handler(struct irq_desc *desc)
311 struct irq_chip *chip = irq_desc_get_chip(desc);
313 chained_irq_enter(chip, desc);
315 for_each_set_bit(i, msm_gpio.enabled_irqs, MAX_NR_GPIO) {
316 if (readl(GPIO_INTR_STATUS(i)) & BIT(INTR_STATUS))
317 generic_handle_irq(irq_find_mapping(msm_gpio.domain,
321 chained_irq_exit(chip, desc);
324 static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
329 if (bitmap_empty(msm_gpio.wake_irqs, MAX_NR_GPIO))
330 irq_set_irq_wake(msm_gpio.summary_irq, 1);
331 set_bit(gpio, msm_gpio.wake_irqs);
333 clear_bit(gpio, msm_gpio.wake_irqs);
334 if (bitmap_empty(msm_gpio.wake_irqs, MAX_NR_GPIO))
335 irq_set_irq_wake(msm_gpio.summary_irq, 0);
341 static struct irq_chip msm_gpio_irq_chip = {
343 .irq_mask = msm_gpio_irq_mask,
344 .irq_unmask = msm_gpio_irq_unmask,
345 .irq_ack = msm_gpio_irq_ack,
346 .irq_set_type = msm_gpio_irq_set_type,
347 .irq_set_wake = msm_gpio_irq_set_wake,
350 static struct lock_class_key msm_gpio_lock_class;
352 static int msm_gpio_irq_domain_map(struct irq_domain *d, unsigned int irq,
353 irq_hw_number_t hwirq)
355 irq_set_lockdep_class(irq, &msm_gpio_lock_class);
356 irq_set_chip_and_handler(irq, &msm_gpio_irq_chip,
362 static const struct irq_domain_ops msm_gpio_irq_domain_ops = {
363 .xlate = irq_domain_xlate_twocell,
364 .map = msm_gpio_irq_domain_map,
367 static int msm_gpio_probe(struct platform_device *pdev)
370 struct resource *res;
372 if (of_property_read_u32(pdev->dev.of_node, "ngpio", &ngpio)) {
373 dev_err(&pdev->dev, "%s: ngpio property missing\n", __func__);
377 if (ngpio > MAX_NR_GPIO)
378 WARN(1, "ngpio exceeds the MAX_NR_GPIO. Increase MAX_NR_GPIO\n");
380 bitmap_zero(msm_gpio.enabled_irqs, MAX_NR_GPIO);
381 bitmap_zero(msm_gpio.wake_irqs, MAX_NR_GPIO);
382 bitmap_zero(msm_gpio.dual_edge_irqs, MAX_NR_GPIO);
384 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
385 msm_gpio.msm_tlmm_base = devm_ioremap_resource(&pdev->dev, res);
386 if (IS_ERR(msm_gpio.msm_tlmm_base))
387 return PTR_ERR(msm_gpio.msm_tlmm_base);
389 msm_gpio.gpio_chip.ngpio = ngpio;
390 msm_gpio.gpio_chip.label = pdev->name;
391 msm_gpio.gpio_chip.dev = &pdev->dev;
392 msm_gpio.gpio_chip.base = 0;
393 msm_gpio.gpio_chip.direction_input = msm_gpio_direction_input;
394 msm_gpio.gpio_chip.direction_output = msm_gpio_direction_output;
395 msm_gpio.gpio_chip.get = msm_gpio_get;
396 msm_gpio.gpio_chip.set = msm_gpio_set;
397 msm_gpio.gpio_chip.to_irq = msm_gpio_to_irq;
398 msm_gpio.gpio_chip.request = msm_gpio_request;
399 msm_gpio.gpio_chip.free = msm_gpio_free;
401 ret = gpiochip_add(&msm_gpio.gpio_chip);
403 dev_err(&pdev->dev, "gpiochip_add failed with error %d\n", ret);
407 msm_gpio.summary_irq = platform_get_irq(pdev, 0);
408 if (msm_gpio.summary_irq < 0) {
409 dev_err(&pdev->dev, "No Summary irq defined for msmgpio\n");
410 return msm_gpio.summary_irq;
413 msm_gpio.domain = irq_domain_add_linear(pdev->dev.of_node, ngpio,
414 &msm_gpio_irq_domain_ops,
416 if (!msm_gpio.domain)
419 irq_set_chained_handler(msm_gpio.summary_irq, msm_summary_irq_handler);
424 static const struct of_device_id msm_gpio_of_match[] = {
425 { .compatible = "qcom,msm-gpio", },
428 MODULE_DEVICE_TABLE(of, msm_gpio_of_match);
430 static int msm_gpio_remove(struct platform_device *dev)
432 gpiochip_remove(&msm_gpio.gpio_chip);
434 irq_set_handler(msm_gpio.summary_irq, NULL);
439 static struct platform_driver msm_gpio_driver = {
440 .probe = msm_gpio_probe,
441 .remove = msm_gpio_remove,
444 .of_match_table = msm_gpio_of_match,
448 module_platform_driver(msm_gpio_driver)
450 MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
451 MODULE_DESCRIPTION("Driver for Qualcomm MSM TLMMv2 SoC GPIOs");
452 MODULE_LICENSE("GPL v2");
453 MODULE_ALIAS("platform:msmgpio");