clocksource/drivers/imx-gpt: Convert init function to return error

The init functions do not return any error. They behave as the following:

  - panic, thus leading to a kernel crash while another timer may work and
       make the system boot up correctly

  or

  - print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/timer-imx-gpt.c

@@ -407,8 +407,10 @@ static const struct imx_gpt_data imx6dl_gpt_data = {
 	.set_next_event = v2_set_next_event,
 };
 
-static void __init _mxc_timer_init(struct imx_timer *imxtm)
+static int __init _mxc_timer_init(struct imx_timer *imxtm)
 {
+	int ret;
+
 	switch (imxtm->type) {
 	case GPT_TYPE_IMX1:
 		imxtm->gpt = &imx1_gpt_data;
@@ -423,12 +425,12 @@ static void __init _mxc_timer_init(struct imx_timer *imxtm)
 		imxtm->gpt = &imx6dl_gpt_data;
 		break;
 	default:
-		BUG();
+		return -EINVAL;
 	}
 
 	if (IS_ERR(imxtm->clk_per)) {
 		pr_err("i.MX timer: unable to get clk\n");
-		return;
+		return PTR_ERR(imxtm->clk_per);
 	}
 
 	if (!IS_ERR(imxtm->clk_ipg))
@@ -446,8 +448,11 @@ static void __init _mxc_timer_init(struct imx_timer *imxtm)
 	imxtm->gpt->gpt_setup_tctl(imxtm);
 
 	/* init and register the timer to the framework */
-	mxc_clocksource_init(imxtm);
-	mxc_clockevent_init(imxtm);
+	ret = mxc_clocksource_init(imxtm);
+	if (ret)
+		return ret;
+
+	return mxc_clockevent_init(imxtm);
 }
 
 void __init mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type)
@@ -469,21 +474,27 @@ void __init mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type)
 	_mxc_timer_init(imxtm);
 }
 
-static void __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
+static int __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
 {
 	struct imx_timer *imxtm;
 	static int initialized;
+	int ret;
 
 	/* Support one instance only */
 	if (initialized)
-		return;
+		return 0;
 
 	imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
-	BUG_ON(!imxtm);
+	if (!imxtm)
+		return -ENOMEM;
 
 	imxtm->base = of_iomap(np, 0);
-	WARN_ON(!imxtm->base);
+	if (!imxtm->base)
+		return -ENXIO;
+
 	imxtm->irq = irq_of_parse_and_map(np, 0);
+	if (imxtm->irq <= 0)
+		return -EINVAL;
 
 	imxtm->clk_ipg = of_clk_get_by_name(np, "ipg");
 
@@ -494,22 +505,26 @@ static void __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type
 
 	imxtm->type = type;
 
-	_mxc_timer_init(imxtm);
+	ret = _mxc_timer_init(imxtm);
+	if (ret)
+		return ret;
 
 	initialized = 1;
+
+	return 0;
 }
 
-static void __init imx1_timer_init_dt(struct device_node *np)
+static int __init imx1_timer_init_dt(struct device_node *np)
 {
-	mxc_timer_init_dt(np, GPT_TYPE_IMX1);
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX1);
 }
 
-static void __init imx21_timer_init_dt(struct device_node *np)
+static int __init imx21_timer_init_dt(struct device_node *np)
 {
-	mxc_timer_init_dt(np, GPT_TYPE_IMX21);
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX21);
 }
 
-static void __init imx31_timer_init_dt(struct device_node *np)
+static int __init imx31_timer_init_dt(struct device_node *np)
 {
 	enum imx_gpt_type type = GPT_TYPE_IMX31;
 
@@ -522,23 +537,23 @@ static void __init imx31_timer_init_dt(struct device_node *np)
 	if (of_machine_is_compatible("fsl,imx6dl"))
 		type = GPT_TYPE_IMX6DL;
 
-	mxc_timer_init_dt(np, type);
+	return mxc_timer_init_dt(np, type);
 }
 
-static void __init imx6dl_timer_init_dt(struct device_node *np)
+static int __init imx6dl_timer_init_dt(struct device_node *np)
 {
-	mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
 }
 
-CLOCKSOURCE_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
-CLOCKSOURCE_OF_DECLARE(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx21_timer, "fsl,imx21-gpt", imx21_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx27_timer, "fsl,imx27-gpt", imx21_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx31_timer, "fsl,imx31-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx25_timer, "fsl,imx25-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx50_timer, "fsl,imx50-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx51_timer, "fsl,imx51-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx53_timer, "fsl,imx53-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx6q_timer, "fsl,imx6q-gpt", imx31_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx6dl_timer, "fsl,imx6dl-gpt", imx6dl_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx6sl_timer, "fsl,imx6sl-gpt", imx6dl_timer_init_dt);
+CLOCKSOURCE_OF_DECLARE_RET(imx6sx_timer, "fsl,imx6sx-gpt", imx6dl_timer_init_dt);