[U-Boot] [PATCH 2/7] lpc32xx: cpu: add support for soft reset

[slemieux.tyco at gmail.com]

From: Sylvain Lemieux <slemieux at tycoint.com>

Add support for optional soft reset (i.e. "RESOUT_N" not asserted during reset).

To be compatible with the original U-Boot code, when the "addr" parameter is 0, a hard is performed; for any other values, a soft reset is done.

Signed-off-by: Sylvain Lemieux <slemieux at tycoint.com>
---
 arch/arm/cpu/arm926ejs/lpc32xx/cpu.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/lpc32xx/cpu.c b/arch/arm/cpu/arm926ejs/lpc32xx/cpu.c
index f757474..bee9318 100644
--- a/arch/arm/cpu/arm926ejs/lpc32xx/cpu.c
+++ b/arch/arm/cpu/arm926ejs/lpc32xx/cpu.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 by Vladimir Zapolskiy <vz at mleia.com>
+ * Copyright (C) 2011-2015 by Vladimir Zapolskiy <vz at mleia.com>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */
@@ -20,12 +20,23 @@ void reset_cpu(ulong addr)
 	/* Enable watchdog clock */
 	setbits_le32(&clk->timclk_ctrl, CLK_TIMCLK_WATCHDOG);
 
-	/* Reset pulse length is 13005 peripheral clock frames */
-	writel(13000, &wdt->pulse);
+	/* To be compatible with the original U-Boot code:
+	 * addr: - 0: perform hard reset.
+	 *       - !=0: perform a soft reset; i.e. "RESOUT_N" not asserted). */
+	if (addr == 0) {
+		/* Reset pulse length is 13005 peripheral clock frames */
+		writel(13000, &wdt->pulse);
 
-	/* Force WDOG_RESET2 and RESOUT_N signal active */
-	writel(WDTIM_MCTRL_RESFRC2 | WDTIM_MCTRL_RESFRC1 | WDTIM_MCTRL_M_RES2,
-	       &wdt->mctrl);
+		/* Force WDOG_RESET2 and RESOUT_N signal active */
+		writel(WDTIM_MCTRL_RESFRC2 | WDTIM_MCTRL_RESFRC1
+		       | WDTIM_MCTRL_M_RES2, &wdt->mctrl);
+	} else {
+		/* Force match output active */
+		writel(0x01, &wdt->emr);
+
+		/* Internal reset on match output (no pulse on "RESOUT_N") */
+		writel(WDTIM_MCTRL_M_RES1, &wdt->mctrl);
+	}
 
 	while (1)
 		/* NOP */;
-- 
1.8.3.1