ARM: shmobile: Break out R-Car SYSC PM code

Break out the R-Car SYSC power management code from
the r8a7779 SoC code. With this new shared R-Car SYSC
code base it is possible to hook in Generation 2 SoCs
as well.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 142 insertions, 0 deletions

diff --git a/arch/arm/mach-shmobile/pm-rcar.c b/arch/arm/mach-shmobile/pm-rcar.c
new file mode 100644
index 000000000000..17225db09558
--- /dev/null
+++ b/arch/arm/mach-shmobile/pm-rcar.c
@@ -0,0 +1,142 @@
+/*
+ * R-Car SYSC Power management support
+ *
+ * Copyright (C) 2014  Magnus Damm
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <asm/io.h>
+#include <mach/pm-rcar.h>
+
+static void __iomem *rcar_sysc_base;
+
+/* SYSC */
+#define SYSCSR 0x00
+#define SYSCISR 0x04
+#define SYSCISCR 0x08
+
+#define PWRSR_OFFS 0x00
+#define PWROFFCR_OFFS 0x04
+#define PWRONCR_OFFS 0x0c
+#define PWRER_OFFS 0x14
+
+#define SYSCSR_RETRIES 100
+#define SYSCSR_DELAY_US 1
+
+#define SYSCISR_RETRIES 1000
+#define SYSCISR_DELAY_US 1
+
+#if defined(CONFIG_PM) || defined(CONFIG_SMP)
+
+static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
+
+static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch,
+				int sr_bit, int reg_offs)
+{
+	int k;
+
+	for (k = 0; k < SYSCSR_RETRIES; k++) {
+		if (ioread32(rcar_sysc_base + SYSCSR) & (1 << sr_bit))
+			break;
+		udelay(SYSCSR_DELAY_US);
+	}
+
+	if (k == SYSCSR_RETRIES)
+		return -EAGAIN;
+
+	iowrite32(1 << sysc_ch->chan_bit,
+		  rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
+
+	return 0;
+}
+
+static int rcar_sysc_pwr_off(struct rcar_sysc_ch *sysc_ch)
+{
+	return rcar_sysc_pwr_on_off(sysc_ch, 0, PWROFFCR_OFFS);
+}
+
+static int rcar_sysc_pwr_on(struct rcar_sysc_ch *sysc_ch)
+{
+	return rcar_sysc_pwr_on_off(sysc_ch, 1, PWRONCR_OFFS);
+}
+
+static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch,
+			    int (*on_off_fn)(struct rcar_sysc_ch *))
+{
+	unsigned int isr_mask = 1 << sysc_ch->isr_bit;
+	unsigned int chan_mask = 1 << sysc_ch->chan_bit;
+	unsigned int status;
+	unsigned long flags;
+	int ret = 0;
+	int k;
+
+	spin_lock_irqsave(&rcar_sysc_lock, flags);
+
+	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
+
+	do {
+		ret = on_off_fn(sysc_ch);
+		if (ret)
+			goto out;
+
+		status = ioread32(rcar_sysc_base +
+				  sysc_ch->chan_offs + PWRER_OFFS);
+	} while (status & chan_mask);
+
+	for (k = 0; k < SYSCISR_RETRIES; k++) {
+		if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
+			break;
+		udelay(SYSCISR_DELAY_US);
+	}
+
+	if (k == SYSCISR_RETRIES)
+		ret = -EIO;
+
+	iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
+
+ out:
+	spin_unlock_irqrestore(&rcar_sysc_lock, flags);
+
+	pr_debug("sysc power domain %d: %08x -> %d\n",
+		 sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
+	return ret;
+}
+
+int rcar_sysc_power_down(struct rcar_sysc_ch *sysc_ch)
+{
+	return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_off);
+}
+
+int rcar_sysc_power_up(struct rcar_sysc_ch *sysc_ch)
+{
+	return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_on);
+}
+
+bool rcar_sysc_power_is_off(struct rcar_sysc_ch *sysc_ch)
+{
+	unsigned int st;
+
+	st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
+	if (st & (1 << sysc_ch->chan_bit))
+		return true;
+
+	return false;
+}
+
+void __iomem *rcar_sysc_init(phys_addr_t base)
+{
+	rcar_sysc_base = ioremap_nocache(base, PAGE_SIZE);
+	if (!rcar_sysc_base)
+		panic("unable to ioremap R-Car SYSC hardware block\n");
+
+	return rcar_sysc_base;
+}
+
+#endif /* CONFIG_PM || CONFIG_SMP */