2 * SPEAr platform PLGPIO driver
4 * Copyright (C) 2012 ST Microelectronics
5 * Viresh Kumar <viresh.kumar@linaro.org>
7 * This file is licensed under the terms of the GNU General Public
8 * License version 2. This program is licensed "as is" without any
9 * warranty of any kind, whether express or implied.
12 #include <linux/clk.h>
13 #include <linux/err.h>
14 #include <linux/gpio/driver.h>
16 #include <linux/module.h>
18 #include <linux/of_platform.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/platform_device.h>
22 #include <linux/spinlock.h>
24 #define MAX_GPIO_PER_REG 32
25 #define PIN_OFFSET(pin) (pin % MAX_GPIO_PER_REG)
26 #define REG_OFFSET(base, reg, pin) (base + reg + (pin / MAX_GPIO_PER_REG) \
30 * plgpio pins in all machines are not one to one mapped, bitwise with registers
31 * bits. These set of macros define register masks for which below functions
32 * (pin_to_offset and offset_to_pin) are required to be called.
34 #define PTO_ENB_REG 0x001
35 #define PTO_WDATA_REG 0x002
36 #define PTO_DIR_REG 0x004
37 #define PTO_IE_REG 0x008
38 #define PTO_RDATA_REG 0x010
39 #define PTO_MIS_REG 0x020
42 u32 enb
; /* enable register */
43 u32 wdata
; /* write data register */
44 u32 dir
; /* direction set register */
45 u32 rdata
; /* read data register */
46 u32 ie
; /* interrupt enable register */
47 u32 mis
; /* mask interrupt status register */
48 u32 eit
; /* edge interrupt type */
52 * struct plgpio: plgpio driver specific structure
54 * lock: lock for guarding gpio registers
55 * base: base address of plgpio block
56 * chip: gpio framework specific chip information structure
57 * p2o: function ptr for pin to offset conversion. This is required only for
58 * machines where mapping b/w pin and offset is not 1-to-1.
59 * o2p: function ptr for offset to pin conversion. This is required only for
60 * machines where mapping b/w pin and offset is not 1-to-1.
61 * p2o_regs: mask of registers for which p2o and o2p are applicable
62 * regs: register offsets
63 * csave_regs: context save registers for standby/sleep/hibernate cases
69 struct gpio_chip chip
;
70 int (*p2o
)(int pin
); /* pin_to_offset */
71 int (*o2p
)(int offset
); /* offset_to_pin */
73 struct plgpio_regs regs
;
74 #ifdef CONFIG_PM_SLEEP
75 struct plgpio_regs
*csave_regs
;
79 /* register manipulation inline functions */
80 static inline u32
is_plgpio_set(void __iomem
*base
, u32 pin
, u32 reg
)
82 u32 offset
= PIN_OFFSET(pin
);
83 void __iomem
*reg_off
= REG_OFFSET(base
, reg
, pin
);
84 u32 val
= readl_relaxed(reg_off
);
86 return !!(val
& (1 << offset
));
89 static inline void plgpio_reg_set(void __iomem
*base
, u32 pin
, u32 reg
)
91 u32 offset
= PIN_OFFSET(pin
);
92 void __iomem
*reg_off
= REG_OFFSET(base
, reg
, pin
);
93 u32 val
= readl_relaxed(reg_off
);
95 writel_relaxed(val
| (1 << offset
), reg_off
);
98 static inline void plgpio_reg_reset(void __iomem
*base
, u32 pin
, u32 reg
)
100 u32 offset
= PIN_OFFSET(pin
);
101 void __iomem
*reg_off
= REG_OFFSET(base
, reg
, pin
);
102 u32 val
= readl_relaxed(reg_off
);
104 writel_relaxed(val
& ~(1 << offset
), reg_off
);
107 /* gpio framework specific routines */
108 static int plgpio_direction_input(struct gpio_chip
*chip
, unsigned offset
)
110 struct plgpio
*plgpio
= gpiochip_get_data(chip
);
113 /* get correct offset for "offset" pin */
114 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& PTO_DIR_REG
)) {
115 offset
= plgpio
->p2o(offset
);
120 spin_lock_irqsave(&plgpio
->lock
, flags
);
121 plgpio_reg_set(plgpio
->base
, offset
, plgpio
->regs
.dir
);
122 spin_unlock_irqrestore(&plgpio
->lock
, flags
);
127 static int plgpio_direction_output(struct gpio_chip
*chip
, unsigned offset
,
130 struct plgpio
*plgpio
= gpiochip_get_data(chip
);
132 unsigned dir_offset
= offset
, wdata_offset
= offset
, tmp
;
134 /* get correct offset for "offset" pin */
135 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& (PTO_DIR_REG
| PTO_WDATA_REG
))) {
136 tmp
= plgpio
->p2o(offset
);
140 if (plgpio
->p2o_regs
& PTO_DIR_REG
)
142 if (plgpio
->p2o_regs
& PTO_WDATA_REG
)
146 spin_lock_irqsave(&plgpio
->lock
, flags
);
148 plgpio_reg_set(plgpio
->base
, wdata_offset
,
151 plgpio_reg_reset(plgpio
->base
, wdata_offset
,
154 plgpio_reg_reset(plgpio
->base
, dir_offset
, plgpio
->regs
.dir
);
155 spin_unlock_irqrestore(&plgpio
->lock
, flags
);
160 static int plgpio_get_value(struct gpio_chip
*chip
, unsigned offset
)
162 struct plgpio
*plgpio
= gpiochip_get_data(chip
);
164 if (offset
>= chip
->ngpio
)
167 /* get correct offset for "offset" pin */
168 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& PTO_RDATA_REG
)) {
169 offset
= plgpio
->p2o(offset
);
174 return is_plgpio_set(plgpio
->base
, offset
, plgpio
->regs
.rdata
);
177 static void plgpio_set_value(struct gpio_chip
*chip
, unsigned offset
, int value
)
179 struct plgpio
*plgpio
= gpiochip_get_data(chip
);
181 if (offset
>= chip
->ngpio
)
184 /* get correct offset for "offset" pin */
185 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& PTO_WDATA_REG
)) {
186 offset
= plgpio
->p2o(offset
);
192 plgpio_reg_set(plgpio
->base
, offset
, plgpio
->regs
.wdata
);
194 plgpio_reg_reset(plgpio
->base
, offset
, plgpio
->regs
.wdata
);
197 static int plgpio_request(struct gpio_chip
*chip
, unsigned offset
)
199 struct plgpio
*plgpio
= gpiochip_get_data(chip
);
200 int gpio
= chip
->base
+ offset
;
204 if (offset
>= chip
->ngpio
)
207 ret
= pinctrl_request_gpio(gpio
);
211 if (!IS_ERR(plgpio
->clk
)) {
212 ret
= clk_enable(plgpio
->clk
);
217 if (plgpio
->regs
.enb
== -1)
221 * put gpio in IN mode before enabling it. This make enabling gpio safe
223 ret
= plgpio_direction_input(chip
, offset
);
227 /* get correct offset for "offset" pin */
228 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& PTO_ENB_REG
)) {
229 offset
= plgpio
->p2o(offset
);
236 spin_lock_irqsave(&plgpio
->lock
, flags
);
237 plgpio_reg_set(plgpio
->base
, offset
, plgpio
->regs
.enb
);
238 spin_unlock_irqrestore(&plgpio
->lock
, flags
);
242 if (!IS_ERR(plgpio
->clk
))
243 clk_disable(plgpio
->clk
);
245 pinctrl_free_gpio(gpio
);
249 static void plgpio_free(struct gpio_chip
*chip
, unsigned offset
)
251 struct plgpio
*plgpio
= gpiochip_get_data(chip
);
252 int gpio
= chip
->base
+ offset
;
255 if (offset
>= chip
->ngpio
)
258 if (plgpio
->regs
.enb
== -1)
261 /* get correct offset for "offset" pin */
262 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& PTO_ENB_REG
)) {
263 offset
= plgpio
->p2o(offset
);
268 spin_lock_irqsave(&plgpio
->lock
, flags
);
269 plgpio_reg_reset(plgpio
->base
, offset
, plgpio
->regs
.enb
);
270 spin_unlock_irqrestore(&plgpio
->lock
, flags
);
273 if (!IS_ERR(plgpio
->clk
))
274 clk_disable(plgpio
->clk
);
276 pinctrl_free_gpio(gpio
);
280 static void plgpio_irq_disable(struct irq_data
*d
)
282 struct gpio_chip
*gc
= irq_data_get_irq_chip_data(d
);
283 struct plgpio
*plgpio
= gpiochip_get_data(gc
);
284 int offset
= d
->hwirq
;
287 /* get correct offset for "offset" pin */
288 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& PTO_IE_REG
)) {
289 offset
= plgpio
->p2o(offset
);
294 spin_lock_irqsave(&plgpio
->lock
, flags
);
295 plgpio_reg_set(plgpio
->base
, offset
, plgpio
->regs
.ie
);
296 spin_unlock_irqrestore(&plgpio
->lock
, flags
);
299 static void plgpio_irq_enable(struct irq_data
*d
)
301 struct gpio_chip
*gc
= irq_data_get_irq_chip_data(d
);
302 struct plgpio
*plgpio
= gpiochip_get_data(gc
);
303 int offset
= d
->hwirq
;
306 /* get correct offset for "offset" pin */
307 if (plgpio
->p2o
&& (plgpio
->p2o_regs
& PTO_IE_REG
)) {
308 offset
= plgpio
->p2o(offset
);
313 spin_lock_irqsave(&plgpio
->lock
, flags
);
314 plgpio_reg_reset(plgpio
->base
, offset
, plgpio
->regs
.ie
);
315 spin_unlock_irqrestore(&plgpio
->lock
, flags
);
318 static int plgpio_irq_set_type(struct irq_data
*d
, unsigned trigger
)
320 struct gpio_chip
*gc
= irq_data_get_irq_chip_data(d
);
321 struct plgpio
*plgpio
= gpiochip_get_data(gc
);
322 int offset
= d
->hwirq
;
323 void __iomem
*reg_off
;
324 unsigned int supported_type
= 0, val
;
326 if (offset
>= plgpio
->chip
.ngpio
)
329 if (plgpio
->regs
.eit
== -1)
330 supported_type
= IRQ_TYPE_LEVEL_HIGH
;
332 supported_type
= IRQ_TYPE_EDGE_RISING
| IRQ_TYPE_EDGE_FALLING
;
334 if (!(trigger
& supported_type
))
337 if (plgpio
->regs
.eit
== -1)
340 reg_off
= REG_OFFSET(plgpio
->base
, plgpio
->regs
.eit
, offset
);
341 val
= readl_relaxed(reg_off
);
343 offset
= PIN_OFFSET(offset
);
344 if (trigger
& IRQ_TYPE_EDGE_RISING
)
345 writel_relaxed(val
| (1 << offset
), reg_off
);
347 writel_relaxed(val
& ~(1 << offset
), reg_off
);
352 static struct irq_chip plgpio_irqchip
= {
354 .irq_enable
= plgpio_irq_enable
,
355 .irq_disable
= plgpio_irq_disable
,
356 .irq_set_type
= plgpio_irq_set_type
,
359 static void plgpio_irq_handler(struct irq_desc
*desc
)
361 struct gpio_chip
*gc
= irq_desc_get_handler_data(desc
);
362 struct plgpio
*plgpio
= gpiochip_get_data(gc
);
363 struct irq_chip
*irqchip
= irq_desc_get_chip(desc
);
364 int regs_count
, count
, pin
, offset
, i
= 0;
365 unsigned long pending
;
367 count
= plgpio
->chip
.ngpio
;
368 regs_count
= DIV_ROUND_UP(count
, MAX_GPIO_PER_REG
);
370 chained_irq_enter(irqchip
, desc
);
371 /* check all plgpio MIS registers for a possible interrupt */
372 for (; i
< regs_count
; i
++) {
373 pending
= readl_relaxed(plgpio
->base
+ plgpio
->regs
.mis
+
378 /* clear interrupts */
379 writel_relaxed(~pending
, plgpio
->base
+ plgpio
->regs
.mis
+
382 * clear extra bits in last register having gpios < MAX/REG
383 * ex: Suppose there are max 102 plgpios. then last register
384 * must have only (102 - MAX_GPIO_PER_REG * 3) = 6 relevant bits
385 * so, we must not take other 28 bits into consideration for
386 * checking interrupt. so clear those bits.
388 count
= count
- i
* MAX_GPIO_PER_REG
;
389 if (count
< MAX_GPIO_PER_REG
)
390 pending
&= (1 << count
) - 1;
392 for_each_set_bit(offset
, &pending
, MAX_GPIO_PER_REG
) {
393 /* get correct pin for "offset" */
394 if (plgpio
->o2p
&& (plgpio
->p2o_regs
& PTO_MIS_REG
)) {
395 pin
= plgpio
->o2p(offset
);
401 /* get correct irq line number */
402 pin
= i
* MAX_GPIO_PER_REG
+ pin
;
404 irq_find_mapping(gc
->irqdomain
, pin
));
407 chained_irq_exit(irqchip
, desc
);
411 * pin to offset and offset to pin converter functions
413 * In spear310 there is inconsistency among bit positions in plgpio regiseters,
414 * for different plgpio pins. For example: for pin 27, bit offset is 23, pin
415 * 28-33 are not supported, pin 95 has offset bit 95, bit 100 has offset bit 1
417 static int spear310_p2o(int pin
)
435 static int spear310_o2p(int offset
)
439 else if (offset
<= 31)
445 static int plgpio_probe_dt(struct platform_device
*pdev
, struct plgpio
*plgpio
)
447 struct device_node
*np
= pdev
->dev
.of_node
;
451 if (of_machine_is_compatible("st,spear310")) {
452 plgpio
->p2o
= spear310_p2o
;
453 plgpio
->o2p
= spear310_o2p
;
454 plgpio
->p2o_regs
= PTO_WDATA_REG
| PTO_DIR_REG
| PTO_IE_REG
|
455 PTO_RDATA_REG
| PTO_MIS_REG
;
458 if (!of_property_read_u32(np
, "st-plgpio,ngpio", &val
)) {
459 plgpio
->chip
.ngpio
= val
;
461 dev_err(&pdev
->dev
, "DT: Invalid ngpio field\n");
465 if (!of_property_read_u32(np
, "st-plgpio,enb-reg", &val
))
466 plgpio
->regs
.enb
= val
;
468 plgpio
->regs
.enb
= -1;
470 if (!of_property_read_u32(np
, "st-plgpio,wdata-reg", &val
)) {
471 plgpio
->regs
.wdata
= val
;
473 dev_err(&pdev
->dev
, "DT: Invalid wdata reg\n");
477 if (!of_property_read_u32(np
, "st-plgpio,dir-reg", &val
)) {
478 plgpio
->regs
.dir
= val
;
480 dev_err(&pdev
->dev
, "DT: Invalid dir reg\n");
484 if (!of_property_read_u32(np
, "st-plgpio,ie-reg", &val
)) {
485 plgpio
->regs
.ie
= val
;
487 dev_err(&pdev
->dev
, "DT: Invalid ie reg\n");
491 if (!of_property_read_u32(np
, "st-plgpio,rdata-reg", &val
)) {
492 plgpio
->regs
.rdata
= val
;
494 dev_err(&pdev
->dev
, "DT: Invalid rdata reg\n");
498 if (!of_property_read_u32(np
, "st-plgpio,mis-reg", &val
)) {
499 plgpio
->regs
.mis
= val
;
501 dev_err(&pdev
->dev
, "DT: Invalid mis reg\n");
505 if (!of_property_read_u32(np
, "st-plgpio,eit-reg", &val
))
506 plgpio
->regs
.eit
= val
;
508 plgpio
->regs
.eit
= -1;
515 static int plgpio_probe(struct platform_device
*pdev
)
517 struct plgpio
*plgpio
;
518 struct resource
*res
;
521 plgpio
= devm_kzalloc(&pdev
->dev
, sizeof(*plgpio
), GFP_KERNEL
);
523 dev_err(&pdev
->dev
, "memory allocation fail\n");
527 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
528 plgpio
->base
= devm_ioremap_resource(&pdev
->dev
, res
);
529 if (IS_ERR(plgpio
->base
))
530 return PTR_ERR(plgpio
->base
);
532 ret
= plgpio_probe_dt(pdev
, plgpio
);
534 dev_err(&pdev
->dev
, "DT probe failed\n");
538 plgpio
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
539 if (IS_ERR(plgpio
->clk
))
540 dev_warn(&pdev
->dev
, "clk_get() failed, work without it\n");
542 #ifdef CONFIG_PM_SLEEP
543 plgpio
->csave_regs
= devm_kzalloc(&pdev
->dev
,
544 sizeof(*plgpio
->csave_regs
) *
545 DIV_ROUND_UP(plgpio
->chip
.ngpio
, MAX_GPIO_PER_REG
),
547 if (!plgpio
->csave_regs
) {
548 dev_err(&pdev
->dev
, "csave registers memory allocation fail\n");
553 platform_set_drvdata(pdev
, plgpio
);
554 spin_lock_init(&plgpio
->lock
);
556 plgpio
->chip
.base
= -1;
557 plgpio
->chip
.request
= plgpio_request
;
558 plgpio
->chip
.free
= plgpio_free
;
559 plgpio
->chip
.direction_input
= plgpio_direction_input
;
560 plgpio
->chip
.direction_output
= plgpio_direction_output
;
561 plgpio
->chip
.get
= plgpio_get_value
;
562 plgpio
->chip
.set
= plgpio_set_value
;
563 plgpio
->chip
.label
= dev_name(&pdev
->dev
);
564 plgpio
->chip
.parent
= &pdev
->dev
;
565 plgpio
->chip
.owner
= THIS_MODULE
;
566 plgpio
->chip
.of_node
= pdev
->dev
.of_node
;
568 if (!IS_ERR(plgpio
->clk
)) {
569 ret
= clk_prepare(plgpio
->clk
);
571 dev_err(&pdev
->dev
, "clk prepare failed\n");
576 ret
= gpiochip_add_data(&plgpio
->chip
, plgpio
);
578 dev_err(&pdev
->dev
, "unable to add gpio chip\n");
582 irq
= platform_get_irq(pdev
, 0);
584 dev_info(&pdev
->dev
, "PLGPIO registered without IRQs\n");
588 ret
= gpiochip_irqchip_add(&plgpio
->chip
,
594 dev_err(&pdev
->dev
, "failed to add irqchip to gpiochip\n");
595 goto remove_gpiochip
;
598 gpiochip_set_chained_irqchip(&plgpio
->chip
,
603 dev_info(&pdev
->dev
, "PLGPIO registered with IRQs\n");
608 dev_info(&pdev
->dev
, "Remove gpiochip\n");
609 gpiochip_remove(&plgpio
->chip
);
611 if (!IS_ERR(plgpio
->clk
))
612 clk_unprepare(plgpio
->clk
);
617 #ifdef CONFIG_PM_SLEEP
618 static int plgpio_suspend(struct device
*dev
)
620 struct plgpio
*plgpio
= dev_get_drvdata(dev
);
621 int i
, reg_count
= DIV_ROUND_UP(plgpio
->chip
.ngpio
, MAX_GPIO_PER_REG
);
624 for (i
= 0; i
< reg_count
; i
++) {
625 off
= plgpio
->base
+ i
* sizeof(int *);
627 if (plgpio
->regs
.enb
!= -1)
628 plgpio
->csave_regs
[i
].enb
=
629 readl_relaxed(plgpio
->regs
.enb
+ off
);
630 if (plgpio
->regs
.eit
!= -1)
631 plgpio
->csave_regs
[i
].eit
=
632 readl_relaxed(plgpio
->regs
.eit
+ off
);
633 plgpio
->csave_regs
[i
].wdata
= readl_relaxed(plgpio
->regs
.wdata
+
635 plgpio
->csave_regs
[i
].dir
= readl_relaxed(plgpio
->regs
.dir
+
637 plgpio
->csave_regs
[i
].ie
= readl_relaxed(plgpio
->regs
.ie
+ off
);
644 * This is used to correct the values in end registers. End registers contain
645 * extra bits that might be used for other purpose in platform. So, we shouldn't
646 * overwrite these bits. This macro, reads given register again, preserves other
647 * bit values (non-plgpio bits), and retain captured value (plgpio bits).
649 #define plgpio_prepare_reg(__reg, _off, _mask, _tmp) \
651 _tmp = readl_relaxed(plgpio->regs.__reg + _off); \
653 plgpio->csave_regs[i].__reg = \
654 _tmp | (plgpio->csave_regs[i].__reg & _mask); \
657 static int plgpio_resume(struct device
*dev
)
659 struct plgpio
*plgpio
= dev_get_drvdata(dev
);
660 int i
, reg_count
= DIV_ROUND_UP(plgpio
->chip
.ngpio
, MAX_GPIO_PER_REG
);
664 for (i
= 0; i
< reg_count
; i
++) {
665 off
= plgpio
->base
+ i
* sizeof(int *);
667 if (i
== reg_count
- 1) {
668 mask
= (1 << (plgpio
->chip
.ngpio
- i
*
669 MAX_GPIO_PER_REG
)) - 1;
671 if (plgpio
->regs
.enb
!= -1)
672 plgpio_prepare_reg(enb
, off
, mask
, tmp
);
674 if (plgpio
->regs
.eit
!= -1)
675 plgpio_prepare_reg(eit
, off
, mask
, tmp
);
677 plgpio_prepare_reg(wdata
, off
, mask
, tmp
);
678 plgpio_prepare_reg(dir
, off
, mask
, tmp
);
679 plgpio_prepare_reg(ie
, off
, mask
, tmp
);
682 writel_relaxed(plgpio
->csave_regs
[i
].wdata
, plgpio
->regs
.wdata
+
684 writel_relaxed(plgpio
->csave_regs
[i
].dir
, plgpio
->regs
.dir
+
687 if (plgpio
->regs
.eit
!= -1)
688 writel_relaxed(plgpio
->csave_regs
[i
].eit
,
689 plgpio
->regs
.eit
+ off
);
691 writel_relaxed(plgpio
->csave_regs
[i
].ie
, plgpio
->regs
.ie
+ off
);
693 if (plgpio
->regs
.enb
!= -1)
694 writel_relaxed(plgpio
->csave_regs
[i
].enb
,
695 plgpio
->regs
.enb
+ off
);
702 static SIMPLE_DEV_PM_OPS(plgpio_dev_pm_ops
, plgpio_suspend
, plgpio_resume
);
704 static const struct of_device_id plgpio_of_match
[] = {
705 { .compatible
= "st,spear-plgpio" },
708 MODULE_DEVICE_TABLE(of
, plgpio_of_match
);
710 static struct platform_driver plgpio_driver
= {
711 .probe
= plgpio_probe
,
713 .name
= "spear-plgpio",
714 .pm
= &plgpio_dev_pm_ops
,
715 .of_match_table
= plgpio_of_match
,
719 static int __init
plgpio_init(void)
721 return platform_driver_register(&plgpio_driver
);
723 subsys_initcall(plgpio_init
);
725 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
726 MODULE_DESCRIPTION("STMicroelectronics SPEAr PLGPIO driver");
727 MODULE_LICENSE("GPL");