ARM: at91/pm: remove CONFIG_AT91_SLOW_CLOCK config option

The slow clock always exists, selecting CONFIG_AT91_SLOW_CLOCK config
is unnecessary for the suspend to memory mode.
For this mode the master clock should always switch to the slow clock.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Tested-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/mach-at91/Kconfig

@@ -118,19 +118,6 @@ endif # SOC_SAM_V4_V5
 
 comment "AT91 Feature Selections"
 
-config AT91_SLOW_CLOCK
-	bool "Suspend-to-RAM disables main oscillator"
-	depends on SUSPEND
-	help
-	  Select this if you want Suspend-to-RAM to save the most power
-	  possible (without powering off the CPU) by disabling the PLLs
-	  and main oscillator so that only the 32 KiHz clock is available.
-
-	  When only that slow-clock is available, some peripherals lose
-	  functionality.  Many can't issue wakeup events unless faster
-	  clocks are available.  Some lose their operating state and
-	  need to be completely re-initialized.
-
 config AT91_TIMER_HZ
        int "Kernel HZ (jiffies per second)"
        range 32 1024

arch/arm/mach-at91/Makefile

@@ -13,7 +13,7 @@ obj-$(CONFIG_SOC_SAMA5)		+= sama5.o
 
 # Power Management
 obj-$(CONFIG_PM)		+= pm.o
-obj-$(CONFIG_AT91_SLOW_CLOCK)	+= pm_slowclock.o
+obj-$(CONFIG_PM)		+= pm_slowclock.o
 
 ifeq ($(CONFIG_PM_DEBUG),y)
 CFLAGS_pm.o += -DDEBUG

arch/arm/mach-at91/pm.c

@@ -123,11 +123,9 @@ EXPORT_SYMBOL(at91_suspend_entering_slow_clock);
 static void (*slow_clock)(void __iomem *pmc, void __iomem *ramc0,
 			  void __iomem *ramc1, int memctrl);
 
-#ifdef CONFIG_AT91_SLOW_CLOCK
 extern void at91_slow_clock(void __iomem *pmc, void __iomem *ramc0,
 			    void __iomem *ramc1, int memctrl);
 extern u32 at91_slow_clock_sz;
-#endif
 
 static int at91_pm_enter(suspend_state_t state)
 {
@@ -151,10 +149,9 @@ static int at91_pm_enter(suspend_state_t state)
 			 * turning off the main oscillator; reverse on wakeup.
 			 */
 			if (slow_clock) {
-#ifdef CONFIG_AT91_SLOW_CLOCK
 				/* copy slow_clock handler to SRAM, and call it */
 				memcpy(slow_clock, at91_slow_clock, at91_slow_clock_sz);
-#endif
+
 				slow_clock(at91_pmc_base, at91_ramc_base[0],
 					   at91_ramc_base[1],
 					   at91_pm_data.memctrl);
@@ -263,7 +260,6 @@ static __init void at91_dt_ramc(void)
 	at91_pm_set_standby(standby);
 }
 
-#ifdef CONFIG_AT91_SLOW_CLOCK
 static void __init at91_pm_sram_init(void)
 {
 	struct gen_pool *sram_pool;
@@ -300,16 +296,10 @@ static void __init at91_pm_sram_init(void)
 	sram_pbase = gen_pool_virt_to_phys(sram_pool, sram_base);
 	slow_clock = __arm_ioremap_exec(sram_pbase, at91_slow_clock_sz, false);
 }
-#endif
-
 
 static void __init at91_pm_init(void)
 {
-#ifdef CONFIG_AT91_SLOW_CLOCK
 	at91_pm_sram_init();
-#endif
-
-	pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock mode)" : ""));
 
 	if (at91_cpuidle_device.dev.platform_data)
 		platform_device_register(&at91_cpuidle_device);