2 * drivers/powergate/tegra-powergate.c
4 * Copyright (c) 2010 Google, Inc
7 * Colin Cross <ccross@google.com>
9 * This software is licensed under the terms of the GNU General Public
10 * License version 2, as published by the Free Software Foundation, and
11 * may be copied, distributed, and modified under those terms.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
20 #include <linux/kernel.h>
21 #include <linux/clk.h>
22 #include <linux/debugfs.h>
23 #include <linux/delay.h>
24 #include <linux/err.h>
25 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/spinlock.h>
31 #include <mach/iomap.h>
32 #include <mach/powergate.h>
34 #define PWRGATE_TOGGLE 0x30
35 #define PWRGATE_TOGGLE_START (1 << 8)
37 #define REMOVE_CLAMPING 0x34
39 #define PWRGATE_STATUS 0x38
41 static DEFINE_SPINLOCK(tegra_powergate_lock);
43 static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE);
45 static u32 pmc_read(unsigned long reg)
47 return readl(pmc + reg);
50 static void pmc_write(u32 val, unsigned long reg)
52 writel(val, pmc + reg);
55 static int tegra_powergate_set(int id, bool new_state)
60 spin_lock_irqsave(&tegra_powergate_lock, flags);
62 status = pmc_read(PWRGATE_STATUS) & (1 << id);
64 if (status == new_state) {
65 spin_unlock_irqrestore(&tegra_powergate_lock, flags);
69 pmc_write(PWRGATE_TOGGLE_START | id, PWRGATE_TOGGLE);
71 spin_unlock_irqrestore(&tegra_powergate_lock, flags);
76 int tegra_powergate_power_on(int id)
78 if (id < 0 || id >= TEGRA_NUM_POWERGATE)
81 return tegra_powergate_set(id, true);
84 int tegra_powergate_power_off(int id)
86 if (id < 0 || id >= TEGRA_NUM_POWERGATE)
89 return tegra_powergate_set(id, false);
92 static bool tegra_powergate_is_powered(int id)
96 WARN_ON(id < 0 || id >= TEGRA_NUM_POWERGATE);
98 status = pmc_read(PWRGATE_STATUS) & (1 << id);
102 int tegra_powergate_remove_clamping(int id)
106 if (id < 0 || id >= TEGRA_NUM_POWERGATE)
110 * Tegra 2 has a bug where PCIE and VDE clamping masks are
111 * swapped relatively to the partition ids
113 if (id == TEGRA_POWERGATE_VDEC)
114 mask = (1 << TEGRA_POWERGATE_PCIE);
115 else if (id == TEGRA_POWERGATE_PCIE)
116 mask = (1 << TEGRA_POWERGATE_VDEC);
120 pmc_write(mask, REMOVE_CLAMPING);
125 /* Must be called with clk disabled, and returns with clk enabled */
126 int tegra_powergate_sequence_power_up(int id, struct clk *clk)
130 tegra_periph_reset_assert(clk);
132 ret = tegra_powergate_power_on(id);
136 ret = clk_enable(clk);
142 ret = tegra_powergate_remove_clamping(id);
147 tegra_periph_reset_deassert(clk);
154 tegra_powergate_power_off(id);
159 #ifdef CONFIG_DEBUG_FS
161 static const char * const powergate_name[] = {
162 [TEGRA_POWERGATE_CPU] = "cpu",
163 [TEGRA_POWERGATE_3D] = "3d",
164 [TEGRA_POWERGATE_VENC] = "venc",
165 [TEGRA_POWERGATE_VDEC] = "vdec",
166 [TEGRA_POWERGATE_PCIE] = "pcie",
167 [TEGRA_POWERGATE_L2] = "l2",
168 [TEGRA_POWERGATE_MPE] = "mpe",
171 static int powergate_show(struct seq_file *s, void *data)
175 seq_printf(s, " powergate powered\n");
176 seq_printf(s, "------------------\n");
178 for (i = 0; i < TEGRA_NUM_POWERGATE; i++)
179 seq_printf(s, " %9s %7s\n", powergate_name[i],
180 tegra_powergate_is_powered(i) ? "yes" : "no");
184 static int powergate_open(struct inode *inode, struct file *file)
186 return single_open(file, powergate_show, inode->i_private);
189 static const struct file_operations powergate_fops = {
190 .open = powergate_open,
193 .release = single_release,
196 static int __init powergate_debugfs_init(void)
201 d = debugfs_create_file("powergate", S_IRUGO, NULL, NULL,
209 late_initcall(powergate_debugfs_init);