2 * arch/arm/mach-at91/pm.c
3 * AT91 Power Management
5 * Copyright (C) 2005 David Brownell
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
13 #include <linux/gpio.h>
14 #include <linux/suspend.h>
15 #include <linux/sched.h>
16 #include <linux/proc_fs.h>
17 #include <linux/genalloc.h>
18 #include <linux/interrupt.h>
19 #include <linux/sysfs.h>
20 #include <linux/module.h>
22 #include <linux/of_platform.h>
23 #include <linux/of_address.h>
24 #include <linux/platform_device.h>
25 #include <linux/platform_data/atmel.h>
27 #include <linux/clk/at91_pmc.h>
30 #include <linux/atomic.h>
31 #include <asm/mach/time.h>
32 #include <asm/mach/irq.h>
33 #include <asm/fncpy.h>
34 #include <asm/cacheflush.h>
35 #include <asm/system_misc.h>
40 static void __iomem
*pmc
;
43 * FIXME: this is needed to communicate between the pinctrl driver and
44 * the PM implementation in the machine. Possibly part of the PM
45 * implementation should be moved down into the pinctrl driver and get
46 * called as part of the generic suspend/resume path.
48 #ifdef CONFIG_PINCTRL_AT91
49 extern void at91_pinctrl_gpio_suspend(void);
50 extern void at91_pinctrl_gpio_resume(void);
54 unsigned long uhp_udp_mask
;
58 void __iomem
*at91_ramc_base
[2];
60 static int at91_pm_valid_state(suspend_state_t state
)
64 case PM_SUSPEND_STANDBY
:
74 static suspend_state_t target_state
;
77 * Called after processes are frozen, but before we shutdown devices.
79 static int at91_pm_begin(suspend_state_t state
)
86 * Verify that all the clocks are correct before entering
89 static int at91_pm_verify_clocks(void)
94 scsr
= readl(pmc
+ AT91_PMC_SCSR
);
96 /* USB must not be using PLLB */
97 if ((scsr
& at91_pm_data
.uhp_udp_mask
) != 0) {
98 pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
102 /* PCK0..PCK3 must be disabled, or configured to use clk32k */
103 for (i
= 0; i
< 4; i
++) {
106 if ((scsr
& (AT91_PMC_PCK0
<< i
)) == 0)
108 css
= readl(pmc
+ AT91_PMC_PCKR(i
)) & AT91_PMC_CSS
;
109 if (css
!= AT91_PMC_CSS_SLOW
) {
110 pr_err("AT91: PM - Suspend-to-RAM with PCK%d src %d\n", i
, css
);
119 * Call this from platform driver suspend() to see how deeply to suspend.
120 * For example, some controllers (like OHCI) need one of the PLL clocks
121 * in order to act as a wakeup source, and those are not available when
122 * going into slow clock mode.
124 * REVISIT: generalize as clk_will_be_available(clk)? Other platforms have
125 * the very same problem (but not using at91 main_clk), and it'd be better
126 * to add one generic API rather than lots of platform-specific ones.
128 int at91_suspend_entering_slow_clock(void)
130 return (target_state
== PM_SUSPEND_MEM
);
132 EXPORT_SYMBOL(at91_suspend_entering_slow_clock
);
134 static void (*at91_suspend_sram_fn
)(void __iomem
*pmc
, void __iomem
*ramc0
,
135 void __iomem
*ramc1
, int memctrl
);
137 extern void at91_pm_suspend_in_sram(void __iomem
*pmc
, void __iomem
*ramc0
,
138 void __iomem
*ramc1
, int memctrl
);
139 extern u32 at91_pm_suspend_in_sram_sz
;
141 static void at91_pm_suspend(suspend_state_t state
)
143 unsigned int pm_data
= at91_pm_data
.memctrl
;
145 pm_data
|= (state
== PM_SUSPEND_MEM
) ?
146 AT91_PM_MODE(AT91_PM_SLOW_CLOCK
) : 0;
151 at91_suspend_sram_fn(pmc
, at91_ramc_base
[0],
152 at91_ramc_base
[1], pm_data
);
157 static int at91_pm_enter(suspend_state_t state
)
159 #ifdef CONFIG_PINCTRL_AT91
160 at91_pinctrl_gpio_suspend();
164 * Suspend-to-RAM is like STANDBY plus slow clock mode, so
165 * drivers must suspend more deeply, the master clock switches
166 * to the clk32k and turns off the main oscillator
170 * Ensure that clocks are in a valid state.
172 if (!at91_pm_verify_clocks())
175 at91_pm_suspend(state
);
180 * STANDBY mode has *all* drivers suspended; ignores irqs not
181 * marked as 'wakeup' event sources; and reduces DRAM power.
182 * But otherwise it's identical to PM_SUSPEND_ON: cpu idle, and
183 * nothing fancy done with main or cpu clocks.
185 case PM_SUSPEND_STANDBY
:
186 at91_pm_suspend(state
);
194 pr_debug("AT91: PM - bogus suspend state %d\n", state
);
199 target_state
= PM_SUSPEND_ON
;
201 #ifdef CONFIG_PINCTRL_AT91
202 at91_pinctrl_gpio_resume();
208 * Called right prior to thawing processes.
210 static void at91_pm_end(void)
212 target_state
= PM_SUSPEND_ON
;
216 static const struct platform_suspend_ops at91_pm_ops
= {
217 .valid
= at91_pm_valid_state
,
218 .begin
= at91_pm_begin
,
219 .enter
= at91_pm_enter
,
223 static struct platform_device at91_cpuidle_device
= {
224 .name
= "cpuidle-at91",
227 static void at91_pm_set_standby(void (*at91_standby
)(void))
230 at91_cpuidle_device
.dev
.platform_data
= at91_standby
;
234 * The AT91RM9200 goes into self-refresh mode with this command, and will
235 * terminate self-refresh automatically on the next SDRAM access.
237 * Self-refresh mode is exited as soon as a memory access is made, but we don't
238 * know for sure when that happens. However, we need to restore the low-power
239 * mode if it was enabled before going idle. Restoring low-power mode while
240 * still in self-refresh is "not recommended", but seems to work.
242 static void at91rm9200_standby(void)
244 u32 lpr
= at91_ramc_read(0, AT91_MC_SDRAMC_LPR
);
249 "1: mcr p15, 0, %0, c7, c10, 4\n\t"
250 " str %0, [%1, %2]\n\t"
251 " str %3, [%1, %4]\n\t"
252 " mcr p15, 0, %0, c7, c0, 4\n\t"
255 : "r" (0), "r" (at91_ramc_base
[0]), "r" (AT91_MC_SDRAMC_LPR
),
256 "r" (1), "r" (AT91_MC_SDRAMC_SRR
),
260 /* We manage both DDRAM/SDRAM controllers, we need more than one value to
263 static void at91_ddr_standby(void)
265 /* Those two values allow us to delay self-refresh activation
268 u32 saved_lpr0
, saved_lpr1
= 0;
270 if (at91_ramc_base
[1]) {
271 saved_lpr1
= at91_ramc_read(1, AT91_DDRSDRC_LPR
);
272 lpr1
= saved_lpr1
& ~AT91_DDRSDRC_LPCB
;
273 lpr1
|= AT91_DDRSDRC_LPCB_SELF_REFRESH
;
276 saved_lpr0
= at91_ramc_read(0, AT91_DDRSDRC_LPR
);
277 lpr0
= saved_lpr0
& ~AT91_DDRSDRC_LPCB
;
278 lpr0
|= AT91_DDRSDRC_LPCB_SELF_REFRESH
;
280 /* self-refresh mode now */
281 at91_ramc_write(0, AT91_DDRSDRC_LPR
, lpr0
);
282 if (at91_ramc_base
[1])
283 at91_ramc_write(1, AT91_DDRSDRC_LPR
, lpr1
);
287 at91_ramc_write(0, AT91_DDRSDRC_LPR
, saved_lpr0
);
288 if (at91_ramc_base
[1])
289 at91_ramc_write(1, AT91_DDRSDRC_LPR
, saved_lpr1
);
292 static void sama5d3_ddr_standby(void)
297 saved_lpr0
= at91_ramc_read(0, AT91_DDRSDRC_LPR
);
298 lpr0
= saved_lpr0
& ~AT91_DDRSDRC_LPCB
;
299 lpr0
|= AT91_DDRSDRC_LPCB_POWER_DOWN
;
301 at91_ramc_write(0, AT91_DDRSDRC_LPR
, lpr0
);
305 at91_ramc_write(0, AT91_DDRSDRC_LPR
, saved_lpr0
);
308 /* We manage both DDRAM/SDRAM controllers, we need more than one value to
311 static void at91sam9_sdram_standby(void)
314 u32 saved_lpr0
, saved_lpr1
= 0;
316 if (at91_ramc_base
[1]) {
317 saved_lpr1
= at91_ramc_read(1, AT91_SDRAMC_LPR
);
318 lpr1
= saved_lpr1
& ~AT91_SDRAMC_LPCB
;
319 lpr1
|= AT91_SDRAMC_LPCB_SELF_REFRESH
;
322 saved_lpr0
= at91_ramc_read(0, AT91_SDRAMC_LPR
);
323 lpr0
= saved_lpr0
& ~AT91_SDRAMC_LPCB
;
324 lpr0
|= AT91_SDRAMC_LPCB_SELF_REFRESH
;
326 /* self-refresh mode now */
327 at91_ramc_write(0, AT91_SDRAMC_LPR
, lpr0
);
328 if (at91_ramc_base
[1])
329 at91_ramc_write(1, AT91_SDRAMC_LPR
, lpr1
);
333 at91_ramc_write(0, AT91_SDRAMC_LPR
, saved_lpr0
);
334 if (at91_ramc_base
[1])
335 at91_ramc_write(1, AT91_SDRAMC_LPR
, saved_lpr1
);
338 static const struct of_device_id ramc_ids
[] __initconst
= {
339 { .compatible
= "atmel,at91rm9200-sdramc", .data
= at91rm9200_standby
},
340 { .compatible
= "atmel,at91sam9260-sdramc", .data
= at91sam9_sdram_standby
},
341 { .compatible
= "atmel,at91sam9g45-ddramc", .data
= at91_ddr_standby
},
342 { .compatible
= "atmel,sama5d3-ddramc", .data
= sama5d3_ddr_standby
},
346 static __init
void at91_dt_ramc(void)
348 struct device_node
*np
;
349 const struct of_device_id
*of_id
;
351 const void *standby
= NULL
;
353 for_each_matching_node_and_match(np
, ramc_ids
, &of_id
) {
354 at91_ramc_base
[idx
] = of_iomap(np
, 0);
355 if (!at91_ramc_base
[idx
])
356 panic(pr_fmt("unable to map ramc[%d] cpu registers\n"), idx
);
359 standby
= of_id
->data
;
365 panic(pr_fmt("unable to find compatible ram controller node in dtb\n"));
368 pr_warn("ramc no standby function available\n");
372 at91_pm_set_standby(standby
);
375 static void at91rm9200_idle(void)
378 * Disable the processor clock. The processor will be automatically
379 * re-enabled by an interrupt or by a reset.
381 writel(AT91_PMC_PCK
, pmc
+ AT91_PMC_SCDR
);
384 static void at91sam9_idle(void)
386 writel(AT91_PMC_PCK
, pmc
+ AT91_PMC_SCDR
);
390 static void __init
at91_pm_sram_init(void)
392 struct gen_pool
*sram_pool
;
393 phys_addr_t sram_pbase
;
394 unsigned long sram_base
;
395 struct device_node
*node
;
396 struct platform_device
*pdev
= NULL
;
398 for_each_compatible_node(node
, NULL
, "mmio-sram") {
399 pdev
= of_find_device_by_node(node
);
407 pr_warn("%s: failed to find sram device!\n", __func__
);
411 sram_pool
= gen_pool_get(&pdev
->dev
, NULL
);
413 pr_warn("%s: sram pool unavailable!\n", __func__
);
417 sram_base
= gen_pool_alloc(sram_pool
, at91_pm_suspend_in_sram_sz
);
419 pr_warn("%s: unable to alloc sram!\n", __func__
);
423 sram_pbase
= gen_pool_virt_to_phys(sram_pool
, sram_base
);
424 at91_suspend_sram_fn
= __arm_ioremap_exec(sram_pbase
,
425 at91_pm_suspend_in_sram_sz
, false);
426 if (!at91_suspend_sram_fn
) {
427 pr_warn("SRAM: Could not map\n");
431 /* Copy the pm suspend handler to SRAM */
432 at91_suspend_sram_fn
= fncpy(at91_suspend_sram_fn
,
433 &at91_pm_suspend_in_sram
, at91_pm_suspend_in_sram_sz
);
436 static const struct of_device_id atmel_pmc_ids
[] __initconst
= {
437 { .compatible
= "atmel,at91rm9200-pmc" },
438 { .compatible
= "atmel,at91sam9260-pmc" },
439 { .compatible
= "atmel,at91sam9g45-pmc" },
440 { .compatible
= "atmel,at91sam9n12-pmc" },
441 { .compatible
= "atmel,at91sam9x5-pmc" },
442 { .compatible
= "atmel,sama5d3-pmc" },
443 { .compatible
= "atmel,sama5d2-pmc" },
447 static void __init
at91_pm_init(void (*pm_idle
)(void))
449 struct device_node
*pmc_np
;
451 if (at91_cpuidle_device
.dev
.platform_data
)
452 platform_device_register(&at91_cpuidle_device
);
454 pmc_np
= of_find_matching_node(NULL
, atmel_pmc_ids
);
455 pmc
= of_iomap(pmc_np
, 0);
457 pr_err("AT91: PM not supported, PMC not found\n");
462 arm_pm_idle
= pm_idle
;
466 if (at91_suspend_sram_fn
)
467 suspend_set_ops(&at91_pm_ops
);
469 pr_info("AT91: PM not supported, due to no SRAM allocated\n");
472 void __init
at91rm9200_pm_init(void)
477 * AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
479 at91_ramc_write(0, AT91_MC_SDRAMC_LPR
, 0);
481 at91_pm_data
.uhp_udp_mask
= AT91RM9200_PMC_UHP
| AT91RM9200_PMC_UDP
;
482 at91_pm_data
.memctrl
= AT91_MEMCTRL_MC
;
484 at91_pm_init(at91rm9200_idle
);
487 void __init
at91sam9260_pm_init(void)
490 at91_pm_data
.memctrl
= AT91_MEMCTRL_SDRAMC
;
491 at91_pm_data
.uhp_udp_mask
= AT91SAM926x_PMC_UHP
| AT91SAM926x_PMC_UDP
;
492 at91_pm_init(at91sam9_idle
);
495 void __init
at91sam9g45_pm_init(void)
498 at91_pm_data
.uhp_udp_mask
= AT91SAM926x_PMC_UHP
;
499 at91_pm_data
.memctrl
= AT91_MEMCTRL_DDRSDR
;
500 at91_pm_init(at91sam9_idle
);
503 void __init
at91sam9x5_pm_init(void)
506 at91_pm_data
.uhp_udp_mask
= AT91SAM926x_PMC_UHP
| AT91SAM926x_PMC_UDP
;
507 at91_pm_data
.memctrl
= AT91_MEMCTRL_DDRSDR
;
508 at91_pm_init(at91sam9_idle
);
511 void __init
sama5_pm_init(void)
514 at91_pm_data
.uhp_udp_mask
= AT91SAM926x_PMC_UHP
| AT91SAM926x_PMC_UDP
;
515 at91_pm_data
.memctrl
= AT91_MEMCTRL_DDRSDR
;