ARM: OMAP1: PM: fix some build warnings on 1510-only Kconfigs

Building an OMAP1510-only Kconfig generates the following warnings:

arch/arm/mach-omap1/pm.c: In function ¡omap1_pm_idle¢:
arch/arm/mach-omap1/pm.c:123:2: warning: #warning Enable 32kHz OS timer in order to allow sleep states in idle [-Wcpp]
 #warning Enable 32kHz OS timer in order to allow sleep states in idle
  ^
arch/arm/mach-omap1/pm.c: At top level:
arch/arm/mach-omap1/pm.c:76:23: warning: ¡enable_dyn_sleep¢ defined but not used [-Wunused-variable]
 static unsigned short enable_dyn_sleep = 0;
                       ^

These are not so easy to fix in an obviously correct fashion, since I
don't have these devices up and running in my testbed.  So, use
arch/arm/plat-omap/Kconfig and the existing pm.c source as a guide,
and posit that deep power saving states are only supported on OMAP16xx
chips with kernels built with both CONFIG_OMAP_DM_TIMER=y and
CONFIG_OMAP_32K_TIMER=y.

While here, clean up a few printk()s and unnecessary #ifdefs.

This second version of the patch incorporates several suggestions from
Jon Hunter <jgchunter@gmail.com>.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Tuukka Tikkanen <tuukka.tikkanen@linaro.org>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Jon Hunter <jgchunter@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap1/pm.c

@@ -71,13 +71,7 @@ static unsigned int mpui7xx_sleep_save[MPUI7XX_SLEEP_SAVE_SIZE];
 static unsigned int mpui1510_sleep_save[MPUI1510_SLEEP_SAVE_SIZE];
 static unsigned int mpui1610_sleep_save[MPUI1610_SLEEP_SAVE_SIZE];
 
-#ifndef CONFIG_OMAP_32K_TIMER
-
-static unsigned short enable_dyn_sleep = 0;
-
-#else
-
-static unsigned short enable_dyn_sleep = 1;
+static unsigned short enable_dyn_sleep;
 
 static ssize_t idle_show(struct kobject *kobj, struct kobj_attribute *attr,
 			 char *buf)
@@ -90,8 +84,9 @@ static ssize_t idle_store(struct kobject *kobj, struct kobj_attribute *attr,
 {
 	unsigned short value;
 	if (sscanf(buf, "%hu", &value) != 1 ||
-	    (value != 0 && value != 1)) {
-		printk(KERN_ERR "idle_sleep_store: Invalid value\n");
+	    (value != 0 && value != 1) ||
+	    (value != 0 && !IS_ENABLED(CONFIG_OMAP_32K_TIMER))) {
+		pr_err("idle_sleep_store: Invalid value\n");
 		return -EINVAL;
 	}
 	enable_dyn_sleep = value;
@@ -101,7 +96,6 @@ static ssize_t idle_store(struct kobject *kobj, struct kobj_attribute *attr,
 static struct kobj_attribute sleep_while_idle_attr =
 	__ATTR(sleep_while_idle, 0644, idle_show, idle_store);
 
-#endif
 
 static void (*omap_sram_suspend)(unsigned long r0, unsigned long r1) = NULL;
 
@@ -115,16 +109,11 @@ void omap1_pm_idle(void)
 {
 	extern __u32 arm_idlect1_mask;
 	__u32 use_idlect1 = arm_idlect1_mask;
-	int do_sleep = 0;
 
 	local_fiq_disable();
 
 #if defined(CONFIG_OMAP_MPU_TIMER) && !defined(CONFIG_OMAP_DM_TIMER)
-#warning Enable 32kHz OS timer in order to allow sleep states in idle
 	use_idlect1 = use_idlect1 & ~(1 << 9);
-#else
-	if (enable_dyn_sleep)
-		do_sleep = 1;
 #endif
 
 #ifdef CONFIG_OMAP_DM_TIMER
@@ -134,10 +123,12 @@ void omap1_pm_idle(void)
 	if (omap_dma_running())
 		use_idlect1 &= ~(1 << 6);
 
-	/* We should be able to remove the do_sleep variable and multiple
+	/*
+	 * We should be able to remove the do_sleep variable and multiple
 	 * tests above as soon as drivers, timer and DMA code have been fixed.
-	 * Even the sleep block count should become obsolete. */
-	if ((use_idlect1 != ~0) || !do_sleep) {
+	 * Even the sleep block count should become obsolete.
+	 */
+	if ((use_idlect1 != ~0) || !enable_dyn_sleep) {
 
 		__u32 saved_idlect1 = omap_readl(ARM_IDLECT1);
 		if (cpu_is_omap15xx())
@@ -635,15 +626,25 @@ static const struct platform_suspend_ops omap_pm_ops = {
 
 static int __init omap_pm_init(void)
 {
-
-#ifdef CONFIG_OMAP_32K_TIMER
-	int error;
-#endif
+	int error = 0;
 
 	if (!cpu_class_is_omap1())
 		return -ENODEV;
 
-	printk("Power Management for TI OMAP.\n");
+	pr_info("Power Management for TI OMAP.\n");
+
+	if (!IS_ENABLED(CONFIG_OMAP_32K_TIMER))
+		pr_info("OMAP1 PM: sleep states in idle disabled due to no 32KiHz timer\n");
+
+	if (!IS_ENABLED(CONFIG_OMAP_DM_TIMER))
+		pr_info("OMAP1 PM: sleep states in idle disabled due to no DMTIMER support\n");
+
+	if (IS_ENABLED(CONFIG_OMAP_32K_TIMER) &&
+	    IS_ENABLED(CONFIG_OMAP_DM_TIMER)) {
+		/* OMAP16xx only */
+		pr_info("OMAP1 PM: sleep states in idle enabled\n");
+		enable_dyn_sleep = 1;
+	}
 
 	/*
 	 * We copy the assembler sleep/wakeup routines to SRAM.
@@ -693,17 +694,15 @@ static int __init omap_pm_init(void)
 	omap_pm_init_debugfs();
 #endif
 
-#ifdef CONFIG_OMAP_32K_TIMER
 	error = sysfs_create_file(power_kobj, &sleep_while_idle_attr.attr);
 	if (error)
 		printk(KERN_ERR "sysfs_create_file failed: %d\n", error);
-#endif
 
 	if (cpu_is_omap16xx()) {
 		/* configure LOW_PWR pin */
 		omap_cfg_reg(T20_1610_LOW_PWR);
 	}
 
-	return 0;
+	return error;
 }
 __initcall(omap_pm_init);