clocksource: tcb_clksrc: Make tc_mode interrupt safe

tc_mode() can be called from interrupt context and thus must not call
clk_*prepare*() functions.

Signed-off-by: David Jander <[e-mail]>
Signed-off-by: Daniel Lezcano <[e-mail]>
Acked-by: Alexandre Belloni <[e-mail]>
Acked-by: Nicolas Ferre <[e-mail]>

drivers/clocksource/tcb_clksrc.c

···
 			|| tcd->clkevt.mode == CLOCK_EVT_MODE_ONESHOT) {
 		__raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR));
 		__raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
-		clk_disable_unprepare(tcd->clk);
+		clk_disable(tcd->clk);
 	}
 
 	switch (m) {
···
 	 * of oneshot, we get lower overhead and improved accuracy.
 	 */
 	case CLOCK_EVT_MODE_PERIODIC:
-		clk_prepare_enable(tcd->clk);
+		clk_enable(tcd->clk);
 
 		/* slow clock, count up to RC, then irq and restart */
 		__raw_writel(timer_clock
···
 		break;
 
 	case CLOCK_EVT_MODE_ONESHOT:
-		clk_prepare_enable(tcd->clk);
+		clk_enable(tcd->clk);
 
 		/* slow clock, count up to RC, then irq and stop */
 		__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
···
 	ret = clk_prepare_enable(t2_clk);
 	if (ret)
 		return ret;
-	clk_disable_unprepare(t2_clk);
+	clk_disable(t2_clk);
 
 	clkevt.regs = tc->regs;
 	clkevt.clk = t2_clk;