Thread (1 message) 1 message, 1 author, 2014-11-10

Re: [PATCH 12/17] ARM: mvebu: Armada XP GP specific suspend/resume code

From: Gregory CLEMENT <hidden>
Date: 2014-11-10 13:53:38
Also in: linux-arm-kernel

Hi Thomas,

[...]
+#include "common.h"
+
+#define ARMADA_XP_GP_PIC_NR_GPIOS 3
+
+static void __iomem *gpio_ctrl;
+static int pic_gpios[ARMADA_XP_GP_PIC_NR_GPIOS];
+static int pic_raw_gpios[ARMADA_XP_GP_PIC_NR_GPIOS];
+
+static void mvebu_armada_xp_gp_pm_enter(void __iomem *sdram_reg, u32 srcmd)
+{
+	u32 reg, ackcmd;
+	int i;
+
+	/* Put 001 as value on the GPIOs */
+	reg = readl(gpio_ctrl);
+	for (i = 0; i < ARMADA_XP_GP_PIC_NR_GPIOS; i++)
+		reg &= ~BIT(pic_raw_gpios[i]);
+	reg |= BIT(pic_raw_gpios[0]);
+	writel(reg, gpio_ctrl);
+
+	/* Prepare writing 111 to the GPIOs */
+	ackcmd = readl(gpio_ctrl);
+	for (i = 0; i < ARMADA_XP_GP_PIC_NR_GPIOS; i++)
+		ackcmd |= BIT(pic_raw_gpios[i]);
+
+	/* Wait a while */
+	mdelay(250);
+
+	asm volatile (
+		/* Align to a cache line */
+		".balign 32\n\t"
+
+		/* Enter self refresh */
+		"str %[srcmd], [%[sdram_reg]]\n\t"
+
+		/* Wait 100 cycles for DDR to enter self refresh */
+		"1: subs r1, r1, #1\n\t"
I should miss something obvious, but I don't see where you load 100 in
the r1 register. According to your comment and the code, you remove 1 from
r1 until it reaches 0, so I expected that just before you have loaded 100 in r1.

Thanks,

Gregory
+		"bne 1b\n\t"
+
+		/* Issue the command ACK */
+		"str %[ackcmd], [%[gpio_ctrl]]\n\t"
+
+		/* Trap the processor */
+		"b .\n\t"
+		: : [srcmd] "r" (srcmd), [sdram_reg] "r" (sdram_reg),
+		  [ackcmd] "r" (ackcmd), [gpio_ctrl] "r" (gpio_ctrl) : "r1");
+}
-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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