Merge tag 'omap-cleanup-timer-for-v3.5' of git://git.kernel.org/pub/s…

…cm/linux/kernel/git/tmlind/linux-omap into next/cleanup2

Timer changes to make it easier to support various SoCs

By Vaibhav Hiremath
via Tony Lindgren
* tag 'omap-cleanup-timer-for-v3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: OMAP: Make OMAP clocksource source selection using kernel param
  ARM: OMAP2+: Replace space with underscore in the name field of system timers
  ARM: OMAP1: Add checks for possible error condition in timer_init

arch/arm/mach-omap1/common.h

@@ -57,7 +57,14 @@ void omap1_init_irq(void);
 void omap1_restart(char, const char *);
 
 extern struct sys_timer omap1_timer;
-extern bool omap_32k_timer_init(void);
+#ifdef CONFIG_OMAP_32K_TIMER
+extern int omap_32k_timer_init(void);
+#else
+static inline int __init omap_32k_timer_init(void)
+{
+	return -ENODEV;
+}
+#endif
 extern void __init omap_init_consistent_dma_size(void);
 
 #endif /* __ARCH_ARM_MACH_OMAP1_COMMON_H */

arch/arm/mach-omap1/time.c

@@ -232,28 +232,14 @@ static inline void omap_mpu_timer_init(void)
 }
 #endif	/* CONFIG_OMAP_MPU_TIMER */
 
-static inline int omap_32k_timer_usable(void)
-{
-	int res = false;
-
-	if (cpu_is_omap730() || cpu_is_omap15xx())
-		return res;
-
-#ifdef CONFIG_OMAP_32K_TIMER
-	res = omap_32k_timer_init();
-#endif
-
-	return res;
-}
-
 /*
  * ---------------------------------------------------------------------------
  * Timer initialization
  * ---------------------------------------------------------------------------
  */
 static void __init omap1_timer_init(void)
 {
-	if (!omap_32k_timer_usable())
+	if (omap_32k_timer_init() != 0)
 		omap_mpu_timer_init();
 }
 

arch/arm/mach-omap1/timer32k.c

@@ -71,6 +71,7 @@
 
 /* 16xx specific defines */
 #define OMAP1_32K_TIMER_BASE		0xfffb9000
+#define OMAP1_32KSYNC_TIMER_BASE	0xfffbc400
 #define OMAP1_32K_TIMER_CR		0x08
 #define OMAP1_32K_TIMER_TVR		0x00
 #define OMAP1_32K_TIMER_TCR		0x04
@@ -182,10 +183,29 @@ static __init void omap_init_32k_timer(void)
  * Timer initialization
  * ---------------------------------------------------------------------------
  */
-bool __init omap_32k_timer_init(void)
+int __init omap_32k_timer_init(void)
 {
-	omap_init_clocksource_32k();
-	omap_init_32k_timer();
+	int ret = -ENODEV;
 
-	return true;
+	if (cpu_is_omap16xx()) {
+		void __iomem *base;
+		struct clk *sync32k_ick;
+
+		base = ioremap(OMAP1_32KSYNC_TIMER_BASE, SZ_1K);
+		if (!base) {
+			pr_err("32k_counter: failed to map base addr\n");
+			return -ENODEV;
+		}
+
+		sync32k_ick = clk_get(NULL, "omap_32ksync_ick");
+		if (!IS_ERR(sync32k_ick))
+			clk_enable(sync32k_ick);
+
+		ret = omap_init_clocksource_32k(base);
+	}
+
+	if (!ret)
+		omap_init_32k_timer();
+
+	return ret;
 }

arch/arm/mach-omap2/timer.c

@@ -90,7 +90,7 @@ static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
 }
 
 static struct irqaction omap2_gp_timer_irq = {
-	.name		= "gp timer",
+	.name		= "gp_timer",
 	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
 	.handler	= omap2_gp_timer_interrupt,
 };
@@ -132,7 +132,7 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
 }
 
 static struct clock_event_device clockevent_gpt = {
-	.name		= "gp timer",
+	.name		= "gp_timer",
 	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 	.shift		= 32,
 	.set_next_event	= omap2_gp_timer_set_next_event,
@@ -236,22 +236,8 @@ static void __init omap2_gp_clockevent_init(int gptimer_id,
 }
 
 /* Clocksource code */
-
-#ifdef CONFIG_OMAP_32K_TIMER
-/*
- * When 32k-timer is enabled, don't use GPTimer for clocksource
- * instead, just leave default clocksource which uses the 32k
- * sync counter.  See clocksource setup in plat-omap/counter_32k.c
- */
-
-static void __init omap2_gp_clocksource_init(int unused, const char *dummy)
-{
-	omap_init_clocksource_32k();
-}
-
-#else
-
 static struct omap_dm_timer clksrc;
+static bool use_gptimer_clksrc;
 
 /*
  * clocksource
@@ -262,7 +248,7 @@ static cycle_t clocksource_read_cycles(struct clocksource *cs)
 }
 
 static struct clocksource clocksource_gpt = {
-	.name		= "gp timer",
+	.name		= "gp_timer",
 	.rating		= 300,
 	.read		= clocksource_read_cycles,
 	.mask		= CLOCKSOURCE_MASK(32),
@@ -278,33 +264,90 @@ static u32 notrace dmtimer_read_sched_clock(void)
 }
 
 /* Setup free-running counter for clocksource */
-static void __init omap2_gp_clocksource_init(int gptimer_id,
+static int __init omap2_sync32k_clocksource_init(void)
+{
+	int ret;
+	struct omap_hwmod *oh;
+	void __iomem *vbase;
+	const char *oh_name = "counter_32k";
+
+	/*
+	 * First check hwmod data is available for sync32k counter
+	 */
+	oh = omap_hwmod_lookup(oh_name);
+	if (!oh || oh->slaves_cnt == 0)
+		return -ENODEV;
+
+	omap_hwmod_setup_one(oh_name);
+
+	vbase = omap_hwmod_get_mpu_rt_va(oh);
+	if (!vbase) {
+		pr_warn("%s: failed to get counter_32k resource\n", __func__);
+		return -ENXIO;
+	}
+
+	ret = omap_hwmod_enable(oh);
+	if (ret) {
+		pr_warn("%s: failed to enable counter_32k module (%d)\n",
+							__func__, ret);
+		return ret;
+	}
+
+	ret = omap_init_clocksource_32k(vbase);
+	if (ret) {
+		pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
+							__func__, ret);
+		omap_hwmod_idle(oh);
+	}
+
+	return ret;
+}
+
+static void __init omap2_gptimer_clocksource_init(int gptimer_id,
 						const char *fck_source)
 {
 	int res;
 
 	res = omap_dm_timer_init_one(&clksrc, gptimer_id, fck_source);
 	BUG_ON(res);
 
-	pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
-		gptimer_id, clksrc.rate);
-
 	__omap_dm_timer_load_start(&clksrc,
 			OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
 	setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
 
 	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
 		pr_err("Could not register clocksource %s\n",
 			clocksource_gpt.name);
+	else
+		pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
+			gptimer_id, clksrc.rate);
+}
+
+static void __init omap2_clocksource_init(int gptimer_id,
+						const char *fck_source)
+{
+	/*
+	 * First give preference to kernel parameter configuration
+	 * by user (clocksource="gp_timer").
+	 *
+	 * In case of missing kernel parameter for clocksource,
+	 * first check for availability for 32k-sync timer, in case
+	 * of failure in finding 32k_counter module or registering
+	 * it as clocksource, execution will fallback to gp-timer.
+	 */
+	if (use_gptimer_clksrc == true)
+		omap2_gptimer_clocksource_init(gptimer_id, fck_source);
+	else if (omap2_sync32k_clocksource_init())
+		/* Fall back to gp-timer code */
+		omap2_gptimer_clocksource_init(gptimer_id, fck_source);
 }
-#endif
 
 #define OMAP_SYS_TIMER_INIT(name, clkev_nr, clkev_src,			\
 				clksrc_nr, clksrc_src)			\
 static void __init omap##name##_timer_init(void)			\
 {									\
 	omap2_gp_clockevent_init((clkev_nr), clkev_src);		\
-	omap2_gp_clocksource_init((clksrc_nr), clksrc_src);		\
+	omap2_clocksource_init((clksrc_nr), clksrc_src);		\
 }
 
 #define OMAP_SYS_TIMER(name)						\
@@ -335,7 +378,7 @@ static DEFINE_TWD_LOCAL_TIMER(twd_local_timer,
 static void __init omap4_timer_init(void)
 {
 	omap2_gp_clockevent_init(1, OMAP4_CLKEV_SOURCE);
-	omap2_gp_clocksource_init(2, OMAP4_MPU_SOURCE);
+	omap2_clocksource_init(2, OMAP4_MPU_SOURCE);
 #ifdef CONFIG_LOCAL_TIMERS
 	/* Local timers are not supprted on OMAP4430 ES1.0 */
 	if (omap_rev() != OMAP4430_REV_ES1_0) {
@@ -503,3 +546,28 @@ static int __init omap2_dm_timer_init(void)
 	return 0;
 }
 arch_initcall(omap2_dm_timer_init);
+
+/**
+ * omap2_override_clocksource - clocksource override with user configuration
+ *
+ * Allows user to override default clocksource, using kernel parameter
+ *   clocksource="gp_timer"	(For all OMAP2PLUS architectures)
+ *
+ * Note that, here we are using same standard kernel parameter "clocksource=",
+ * and not introducing any OMAP specific interface.
+ */
+static int __init omap2_override_clocksource(char *str)
+{
+	if (!str)
+		return 0;
+	/*
+	 * For OMAP architecture, we only have two options
+	 *    - sync_32k (default)
+	 *    - gp_timer (sys_clk based)
+	 */
+	if (!strcmp(str, "gp_timer"))
+		use_gptimer_clksrc = true;
+
+	return 0;
+}
+early_param("clocksource", omap2_override_clocksource);

arch/arm/plat-omap/counter_32k.c

@@ -27,19 +27,20 @@
 
 #include <plat/clock.h>
 
+/* OMAP2_32KSYNCNT_CR_OFF: offset of 32ksync counter register */
+#define OMAP2_32KSYNCNT_CR_OFF		0x10
+
 /*
  * 32KHz clocksource ... always available, on pretty most chips except
  * OMAP 730 and 1510.  Other timers could be used as clocksources, with
  * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
  * but systems won't necessarily want to spend resources that way.
  */
-static void __iomem *timer_32k_base;
-
-#define OMAP16XX_TIMER_32K_SYNCHRONIZED		0xfffbc410
+static void __iomem *sync32k_cnt_reg;
 
 static u32 notrace omap_32k_read_sched_clock(void)
 {
-	return timer_32k_base ? __raw_readl(timer_32k_base) : 0;
+	return sync32k_cnt_reg ? __raw_readl(sync32k_cnt_reg) : 0;
 }
 
 /**
@@ -59,7 +60,7 @@ void read_persistent_clock(struct timespec *ts)
 	struct timespec *tsp = &persistent_ts;
 
 	last_cycles = cycles;
-	cycles = timer_32k_base ? __raw_readl(timer_32k_base) : 0;
+	cycles = sync32k_cnt_reg ? __raw_readl(sync32k_cnt_reg) : 0;
 	delta = cycles - last_cycles;
 
 	nsecs = clocksource_cyc2ns(delta, persistent_mult, persistent_shift);
@@ -68,54 +69,40 @@ void read_persistent_clock(struct timespec *ts)
 	*ts = *tsp;
 }
 
-int __init omap_init_clocksource_32k(void)
+/**
+ * omap_init_clocksource_32k - setup and register counter 32k as a
+ * kernel clocksource
+ * @pbase: base addr of counter_32k module
+ * @size: size of counter_32k to map
+ *
+ * Returns 0 upon success or negative error code upon failure.
+ *
+ */
+int __init omap_init_clocksource_32k(void __iomem *vbase)
 {
-	static char err[] __initdata = KERN_ERR
-			"%s: can't register clocksource!\n";
-
-	if (cpu_is_omap16xx() || cpu_class_is_omap2()) {
-		u32 pbase;
-		unsigned long size = SZ_4K;
-		void __iomem *base;
-		struct clk *sync_32k_ick;
-
-		if (cpu_is_omap16xx()) {
-			pbase = OMAP16XX_TIMER_32K_SYNCHRONIZED;
-			size = SZ_1K;
-		} else if (cpu_is_omap2420())
-			pbase = OMAP2420_32KSYNCT_BASE + 0x10;
-		else if (cpu_is_omap2430())
-			pbase = OMAP2430_32KSYNCT_BASE + 0x10;
-		else if (cpu_is_omap34xx())
-			pbase = OMAP3430_32KSYNCT_BASE + 0x10;
-		else if (cpu_is_omap44xx())
-			pbase = OMAP4430_32KSYNCT_BASE + 0x10;
-		else
-			return -ENODEV;
-
-		/* For this to work we must have a static mapping in io.c for this area */
-		base = ioremap(pbase, size);
-		if (!base)
-			return -ENODEV;
-
-		sync_32k_ick = clk_get(NULL, "omap_32ksync_ick");
-		if (!IS_ERR(sync_32k_ick))
-			clk_enable(sync_32k_ick);
-
-		timer_32k_base = base;
-
-		/*
-		 * 120000 rough estimate from the calculations in
-		 * __clocksource_updatefreq_scale.
-		 */
-		clocks_calc_mult_shift(&persistent_mult, &persistent_shift,
-				32768, NSEC_PER_SEC, 120000);
-
-		if (clocksource_mmio_init(base, "32k_counter", 32768, 250, 32,
-					  clocksource_mmio_readl_up))
-			printk(err, "32k_counter");
-
-		setup_sched_clock(omap_32k_read_sched_clock, 32, 32768);
+	int ret;
+
+	/*
+	 * 32k sync Counter register offset is at 0x10
+	 */
+	sync32k_cnt_reg = vbase + OMAP2_32KSYNCNT_CR_OFF;
+
+	/*
+	 * 120000 rough estimate from the calculations in
+	 * __clocksource_updatefreq_scale.
+	 */
+	clocks_calc_mult_shift(&persistent_mult, &persistent_shift,
+			32768, NSEC_PER_SEC, 120000);
+
+	ret = clocksource_mmio_init(sync32k_cnt_reg, "32k_counter", 32768,
+				250, 32, clocksource_mmio_readl_up);
+	if (ret) {
+		pr_err("32k_counter: can't register clocksource\n");
+		return ret;
 	}
+
+	setup_sched_clock(omap_32k_read_sched_clock, 32, 32768);
+	pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
+
 	return 0;
 }