warp.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * PIKA Warp(tm) board specific routines
  4 *
  5 * Copyright (c) 2008-2009 PIKA Technologies
  6 *   Sean MacLennan <smaclennan@pikatech.com>
  7 */
  8#include <linux/err.h>
  9#include <linux/init.h>
 10#include <linux/of_platform.h>
 11#include <linux/platform_device.h>
 12#include <linux/kthread.h>
 13#include <linux/leds.h>
 14#include <linux/i2c.h>
 15#include <linux/interrupt.h>
 16#include <linux/delay.h>
 17#include <linux/of_address.h>
 18#include <linux/of_irq.h>
 19#include <linux/gpio/consumer.h>
 20#include <linux/slab.h>
 21#include <linux/export.h>
 22
 23#include <asm/machdep.h>
 24#include <asm/udbg.h>
 25#include <asm/time.h>
 26#include <asm/uic.h>
 27#include <asm/ppc4xx.h>
 28#include <asm/dma.h>
 29
 30
 31static const struct of_device_id warp_of_bus[] __initconst = {
 32	{ .compatible = "ibm,plb4", },
 33	{ .compatible = "ibm,opb", },
 34	{ .compatible = "ibm,ebc", },
 35	{},
 36};
 37
 38static int __init warp_device_probe(void)
 39{
 40	of_platform_bus_probe(NULL, warp_of_bus, NULL);
 41	return 0;
 42}
 43machine_device_initcall(warp, warp_device_probe);
 44
 45define_machine(warp) {
 46	.name		= "Warp",
 47	.compatible	= "pika,warp",
 48	.progress 	= udbg_progress,
 49	.init_IRQ 	= uic_init_tree,
 50	.get_irq 	= uic_get_irq,
 51	.restart	= ppc4xx_reset_system,
 52};
 53
 54
 55static int __init warp_post_info(void)
 56{
 57	struct device_node *np;
 58	void __iomem *fpga;
 59	u32 post1, post2;
 60
 61	/* Sighhhh... POST information is in the sd area. */
 62	np = of_find_compatible_node(NULL, NULL, "pika,fpga-sd");
 63	if (np == NULL)
 64		return -ENOENT;
 65
 66	fpga = of_iomap(np, 0);
 67	of_node_put(np);
 68	if (fpga == NULL)
 69		return -ENOENT;
 70
 71	post1 = in_be32(fpga + 0x40);
 72	post2 = in_be32(fpga + 0x44);
 73
 74	iounmap(fpga);
 75
 76	if (post1 || post2)
 77		printk(KERN_INFO "Warp POST %08x %08x\n", post1, post2);
 78	else
 79		printk(KERN_INFO "Warp POST OK\n");
 80
 81	return 0;
 82}
 83
 84
 85#ifdef CONFIG_SENSORS_AD7414
 86
 87static void __iomem *dtm_fpga;
 88
 89#define WARP_GREEN_LED	0
 90#define WARP_RED_LED	1
 91
 92static struct gpio_led warp_gpio_led_pins[] = {
 93	[WARP_GREEN_LED] = {
 94		.name		= "green",
 95		.default_state	= LEDS_DEFSTATE_KEEP,
 96		.gpiod		= NULL, /* to be filled by pika_setup_leds() */
 97	},
 98	[WARP_RED_LED] = {
 99		.name		= "red",
100		.default_state	= LEDS_DEFSTATE_KEEP,
101		.gpiod		= NULL, /* to be filled by pika_setup_leds() */
102	},
103};
104
105static struct gpio_led_platform_data warp_gpio_led_data = {
106	.leds		= warp_gpio_led_pins,
107	.num_leds	= ARRAY_SIZE(warp_gpio_led_pins),
108};
109
110static struct platform_device warp_gpio_leds = {
111	.name	= "leds-gpio",
112	.id	= -1,
113	.dev	= {
114		.platform_data = &warp_gpio_led_data,
115	},
116};
117
118static irqreturn_t temp_isr(int irq, void *context)
119{
120	int value = 1;
121
122	local_irq_disable();
123
124	gpiod_set_value(warp_gpio_led_pins[WARP_GREEN_LED].gpiod, 0);
125
126	printk(KERN_EMERG "\n\nCritical Temperature Shutdown\n\n");
127
128	while (1) {
129		if (dtm_fpga) {
130			unsigned reset = in_be32(dtm_fpga + 0x14);
131			out_be32(dtm_fpga + 0x14, reset);
132		}
133
134		gpiod_set_value(warp_gpio_led_pins[WARP_RED_LED].gpiod, value);
135		value ^= 1;
136		mdelay(500);
137	}
138
139	/* Not reached */
140	return IRQ_HANDLED;
141}
142
143/*
144 * Because green and red power LEDs are normally driven by leds-gpio driver,
145 * but in case of critical temperature shutdown we want to drive them
146 * ourselves, we acquire both and then create leds-gpio platform device
147 * ourselves, instead of doing it through device tree. This way we can still
148 * keep access to the gpios and use them when needed.
149 */
150static int pika_setup_leds(void)
151{
152	struct device_node *np, *child;
153	struct gpio_desc *gpio;
154	struct gpio_led *led;
155	int led_count = 0;
156	int error;
157	int i;
158
159	np = of_find_compatible_node(NULL, NULL, "warp-power-leds");
160	if (!np) {
161		printk(KERN_ERR __FILE__ ": Unable to find leds\n");
162		return -ENOENT;
163	}
164
165	for_each_child_of_node(np, child) {
166		for (i = 0; i < ARRAY_SIZE(warp_gpio_led_pins); i++) {
167			led = &warp_gpio_led_pins[i];
168
169			if (!of_node_name_eq(child, led->name))
170				continue;
171
172			if (led->gpiod) {
173				printk(KERN_ERR __FILE__ ": %s led has already been defined\n",
174				       led->name);
175				continue;
176			}
177
178			gpio = fwnode_gpiod_get_index(of_fwnode_handle(child),
179						      NULL, 0, GPIOD_ASIS,
180						      led->name);
181			error = PTR_ERR_OR_ZERO(gpio);
182			if (error) {
183				printk(KERN_ERR __FILE__ ": Failed to get %s led gpio: %d\n",
184				       led->name, error);
185				of_node_put(child);
186				goto err_cleanup_pins;
187			}
188
189			led->gpiod = gpio;
190			led_count++;
191		}
192	}
193
194	of_node_put(np);
195
196	/* Skip device registration if no leds have been defined */
197	if (led_count) {
198		error = platform_device_register(&warp_gpio_leds);
199		if (error) {
200			printk(KERN_ERR __FILE__ ": Unable to add leds-gpio: %d\n",
201			       error);
202			goto err_cleanup_pins;
203		}
204	}
205
206	return 0;
207
208err_cleanup_pins:
209	for (i = 0; i < ARRAY_SIZE(warp_gpio_led_pins); i++) {
210		led = &warp_gpio_led_pins[i];
211		gpiod_put(led->gpiod);
212		led->gpiod = NULL;
213	}
214	return error;
215}
216
217static void pika_setup_critical_temp(struct device_node *np,
218				     struct i2c_client *client)
219{
220	int irq, rc;
221
222	/* Do this before enabling critical temp interrupt since we
223	 * may immediately interrupt.
224	 */
225	pika_setup_leds();
226
227	/* These registers are in 1 degree increments. */
228	i2c_smbus_write_byte_data(client, 2, 65); /* Thigh */
229	i2c_smbus_write_byte_data(client, 3,  0); /* Tlow */
230
231	irq = irq_of_parse_and_map(np, 0);
232	if (!irq) {
233		printk(KERN_ERR __FILE__ ": Unable to get ad7414 irq\n");
234		return;
235	}
236
237	rc = request_irq(irq, temp_isr, 0, "ad7414", NULL);
238	if (rc) {
239		printk(KERN_ERR __FILE__
240		       ": Unable to request ad7414 irq %d = %d\n", irq, rc);
241		return;
242	}
243}
244
245static inline void pika_dtm_check_fan(void __iomem *fpga)
246{
247	static int fan_state;
248	u32 fan = in_be32(fpga + 0x34) & (1 << 14);
249
250	if (fan_state != fan) {
251		fan_state = fan;
252		if (fan)
253			printk(KERN_WARNING "Fan rotation error detected."
254				   " Please check hardware.\n");
255	}
256}
257
258static int pika_dtm_thread(void __iomem *fpga)
259{
260	struct device_node *np;
261	struct i2c_client *client;
262
263	np = of_find_compatible_node(NULL, NULL, "adi,ad7414");
264	if (np == NULL)
265		return -ENOENT;
266
267	client = of_find_i2c_device_by_node(np);
268	if (client == NULL) {
269		of_node_put(np);
270		return -ENOENT;
271	}
272
273	pika_setup_critical_temp(np, client);
274
275	of_node_put(np);
276
277	printk(KERN_INFO "Warp DTM thread running.\n");
278
279	while (!kthread_should_stop()) {
280		int val;
281
282		val = i2c_smbus_read_word_data(client, 0);
283		if (val < 0)
284			dev_dbg(&client->dev, "DTM read temp failed.\n");
285		else {
286			s16 temp = swab16(val);
287			out_be32(fpga + 0x20, temp);
288		}
289
290		pika_dtm_check_fan(fpga);
291
292		set_current_state(TASK_INTERRUPTIBLE);
293		schedule_timeout(HZ);
294	}
295
296	return 0;
297}
298
299static int __init pika_dtm_start(void)
300{
301	struct task_struct *dtm_thread;
302	struct device_node *np;
303
304	np = of_find_compatible_node(NULL, NULL, "pika,fpga");
305	if (np == NULL)
306		return -ENOENT;
307
308	dtm_fpga = of_iomap(np, 0);
309	of_node_put(np);
310	if (dtm_fpga == NULL)
311		return -ENOENT;
312
313	/* Must get post info before thread starts. */
314	warp_post_info();
315
316	dtm_thread = kthread_run(pika_dtm_thread, dtm_fpga, "pika-dtm");
317	if (IS_ERR(dtm_thread)) {
318		iounmap(dtm_fpga);
319		return PTR_ERR(dtm_thread);
320	}
321
322	return 0;
323}
324machine_late_initcall(warp, pika_dtm_start);
325
326#else /* !CONFIG_SENSORS_AD7414 */
327
328machine_late_initcall(warp, warp_post_info);
329
330#endif