[PATCH v2 06/28] ARM: tegra: Add api to control internal powergating
Colin Cross
ccross at android.com
Sun Jan 23 21:01:11 EST 2011
Signed-off-by: Colin Cross <ccross at android.com>
---
arch/arm/mach-tegra/Makefile | 1 +
arch/arm/mach-tegra/include/mach/powergate.h | 40 +++++
arch/arm/mach-tegra/powergate.c | 212 ++++++++++++++++++++++++++
3 files changed, 253 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-tegra/include/mach/powergate.h
create mode 100644 arch/arm/mach-tegra/powergate.c
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index cdbc68e..00a6ba3 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -5,6 +5,7 @@ obj-y += clock.o
obj-y += timer.o
obj-y += gpio.o
obj-y += pinmux.o
+obj-y += powergate.o
obj-y += fuse.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += clock.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_clocks.o
diff --git a/arch/arm/mach-tegra/include/mach/powergate.h b/arch/arm/mach-tegra/include/mach/powergate.h
new file mode 100644
index 0000000..401d1b7
--- /dev/null
+++ b/arch/arm/mach-tegra/include/mach/powergate.h
@@ -0,0 +1,40 @@
+/*
+ * drivers/regulator/tegra-regulator.c
+ *
+ * Copyright (c) 2010 Google, Inc
+ *
+ * Author:
+ * Colin Cross <ccross at google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _MACH_TEGRA_POWERGATE_H_
+#define _MACH_TEGRA_POWERGATE_H_
+
+#define TEGRA_POWERGATE_CPU 0
+#define TEGRA_POWERGATE_3D 1
+#define TEGRA_POWERGATE_VENC 2
+#define TEGRA_POWERGATE_PCIE 3
+#define TEGRA_POWERGATE_VDEC 4
+#define TEGRA_POWERGATE_L2 5
+#define TEGRA_POWERGATE_MPE 6
+#define TEGRA_NUM_POWERGATE 7
+
+int tegra_powergate_power_on(int id);
+int tegra_powergate_power_off(int id);
+bool tegra_powergate_is_powered(int id);
+int tegra_powergate_remove_clamping(int id);
+
+/* Must be called with clk disabled, and returns with clk enabled */
+int tegra_powergate_sequence_power_up(int id, struct clk *clk);
+
+#endif /* _MACH_TEGRA_POWERGATE_H_ */
diff --git a/arch/arm/mach-tegra/powergate.c b/arch/arm/mach-tegra/powergate.c
new file mode 100644
index 0000000..3cee9aa
--- /dev/null
+++ b/arch/arm/mach-tegra/powergate.c
@@ -0,0 +1,212 @@
+/*
+ * drivers/powergate/tegra-powergate.c
+ *
+ * Copyright (c) 2010 Google, Inc
+ *
+ * Author:
+ * Colin Cross <ccross at google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+
+#include <mach/clk.h>
+#include <mach/iomap.h>
+#include <mach/powergate.h>
+
+#define PWRGATE_TOGGLE 0x30
+#define PWRGATE_TOGGLE_START (1 << 8)
+
+#define REMOVE_CLAMPING 0x34
+
+#define PWRGATE_STATUS 0x38
+
+static DEFINE_SPINLOCK(tegra_powergate_lock);
+
+static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE);
+
+static u32 pmc_read(unsigned long reg)
+{
+ return readl(pmc + reg);
+}
+
+static void pmc_write(u32 val, unsigned long reg)
+{
+ writel(val, pmc + reg);
+}
+
+static int tegra_powergate_set(int id, bool new_state)
+{
+ bool status;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tegra_powergate_lock, flags);
+
+ status = pmc_read(PWRGATE_STATUS) & (1 << id);
+
+ if (status == new_state) {
+ spin_unlock_irqrestore(&tegra_powergate_lock, flags);
+ return -EINVAL;
+ }
+
+ pmc_write(PWRGATE_TOGGLE_START | id, PWRGATE_TOGGLE);
+
+ spin_unlock_irqrestore(&tegra_powergate_lock, flags);
+
+ return 0;
+}
+
+int tegra_powergate_power_on(int id)
+{
+ if (id < 0 || id >= TEGRA_NUM_POWERGATE)
+ return -EINVAL;
+
+ return tegra_powergate_set(id, true);
+}
+
+int tegra_powergate_power_off(int id)
+{
+ if (id < 0 || id >= TEGRA_NUM_POWERGATE)
+ return -EINVAL;
+
+ return tegra_powergate_set(id, false);
+}
+
+bool tegra_powergate_is_powered(int id)
+{
+ u32 status;
+
+ if (id < 0 || id >= TEGRA_NUM_POWERGATE)
+ return -EINVAL;
+
+ status = pmc_read(PWRGATE_STATUS) & (1 << id);
+ return !!status;
+}
+
+int tegra_powergate_remove_clamping(int id)
+{
+ u32 mask;
+
+ if (id < 0 || id >= TEGRA_NUM_POWERGATE)
+ return -EINVAL;
+
+ /*
+ * Tegra 2 has a bug where PCIE and VDE clamping masks are
+ * swapped relatively to the partition ids
+ */
+ if (id == TEGRA_POWERGATE_VDEC)
+ mask = (1 << TEGRA_POWERGATE_PCIE);
+ else if (id == TEGRA_POWERGATE_PCIE)
+ mask = (1 << TEGRA_POWERGATE_VDEC);
+ else
+ mask = (1 << id);
+
+ pmc_write(mask, REMOVE_CLAMPING);
+
+ return 0;
+}
+
+/* Must be called with clk disabled, and returns with clk enabled */
+int tegra_powergate_sequence_power_up(int id, struct clk *clk)
+{
+ int ret;
+
+ tegra_periph_reset_assert(clk);
+
+ ret = tegra_powergate_power_on(id);
+ if (ret)
+ goto err_power;
+
+ ret = clk_enable(clk);
+ if (ret)
+ goto err_clk;
+
+ udelay(10);
+
+ ret = tegra_powergate_remove_clamping(id);
+ if (ret)
+ goto err_clamp;
+
+ udelay(10);
+ tegra_periph_reset_deassert(clk);
+
+ return 0;
+
+err_clamp:
+ clk_disable(clk);
+err_clk:
+ tegra_powergate_power_off(id);
+err_power:
+ return ret;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static const char * const powergate_name[] = {
+ [TEGRA_POWERGATE_CPU] = "cpu",
+ [TEGRA_POWERGATE_3D] = "3d",
+ [TEGRA_POWERGATE_VENC] = "venc",
+ [TEGRA_POWERGATE_VDEC] = "vdec",
+ [TEGRA_POWERGATE_PCIE] = "pcie",
+ [TEGRA_POWERGATE_L2] = "l2",
+ [TEGRA_POWERGATE_MPE] = "mpe",
+};
+
+static int powergate_show(struct seq_file *s, void *data)
+{
+ int i;
+
+ seq_printf(s, " powergate powered\n");
+ seq_printf(s, "------------------\n");
+
+ for (i = 0; i < TEGRA_NUM_POWERGATE; i++)
+ seq_printf(s, " %9s %7s\n", powergate_name[i],
+ tegra_powergate_is_powered(i) ? "yes" : "no");
+ return 0;
+}
+
+static int powergate_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, powergate_show, inode->i_private);
+}
+
+static const struct file_operations powergate_fops = {
+ .open = powergate_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init powergate_debugfs_init(void)
+{
+ struct dentry *d;
+ int err = -ENOMEM;
+
+ d = debugfs_create_file("powergate", S_IRUGO, NULL, NULL,
+ &powergate_fops);
+ if (!d)
+ return -ENOMEM;
+
+ return err;
+}
+
+late_initcall(powergate_debugfs_init);
+
+#endif
--
1.7.3.1
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