Colin Cross | ce1e326 | 2010-05-24 17:07:46 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * drivers/powergate/tegra-powergate.c |
| 3 | * |
| 4 | * Copyright (c) 2010 Google, Inc |
| 5 | * |
| 6 | * Author: |
| 7 | * Colin Cross <ccross@google.com> |
| 8 | * |
| 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. |
| 12 | * |
| 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. |
| 17 | * |
| 18 | */ |
| 19 | |
| 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> |
| 26 | #include <linux/io.h> |
| 27 | #include <linux/seq_file.h> |
| 28 | #include <linux/spinlock.h> |
| 29 | |
| 30 | #include <mach/clk.h> |
| 31 | #include <mach/iomap.h> |
| 32 | #include <mach/powergate.h> |
| 33 | |
| 34 | #define PWRGATE_TOGGLE 0x30 |
| 35 | #define PWRGATE_TOGGLE_START (1 << 8) |
| 36 | |
| 37 | #define REMOVE_CLAMPING 0x34 |
| 38 | |
| 39 | #define PWRGATE_STATUS 0x38 |
| 40 | |
| 41 | static DEFINE_SPINLOCK(tegra_powergate_lock); |
| 42 | |
| 43 | static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE); |
| 44 | |
| 45 | static u32 pmc_read(unsigned long reg) |
| 46 | { |
| 47 | return readl(pmc + reg); |
| 48 | } |
| 49 | |
| 50 | static void pmc_write(u32 val, unsigned long reg) |
| 51 | { |
| 52 | writel(val, pmc + reg); |
| 53 | } |
| 54 | |
| 55 | static int tegra_powergate_set(int id, bool new_state) |
| 56 | { |
| 57 | bool status; |
| 58 | unsigned long flags; |
| 59 | |
| 60 | spin_lock_irqsave(&tegra_powergate_lock, flags); |
| 61 | |
| 62 | status = pmc_read(PWRGATE_STATUS) & (1 << id); |
| 63 | |
| 64 | if (status == new_state) { |
| 65 | spin_unlock_irqrestore(&tegra_powergate_lock, flags); |
| 66 | return -EINVAL; |
| 67 | } |
| 68 | |
| 69 | pmc_write(PWRGATE_TOGGLE_START | id, PWRGATE_TOGGLE); |
| 70 | |
| 71 | spin_unlock_irqrestore(&tegra_powergate_lock, flags); |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | int tegra_powergate_power_on(int id) |
| 77 | { |
| 78 | if (id < 0 || id >= TEGRA_NUM_POWERGATE) |
| 79 | return -EINVAL; |
| 80 | |
| 81 | return tegra_powergate_set(id, true); |
| 82 | } |
| 83 | |
| 84 | int tegra_powergate_power_off(int id) |
| 85 | { |
| 86 | if (id < 0 || id >= TEGRA_NUM_POWERGATE) |
| 87 | return -EINVAL; |
| 88 | |
| 89 | return tegra_powergate_set(id, false); |
| 90 | } |
| 91 | |
| 92 | bool tegra_powergate_is_powered(int id) |
| 93 | { |
| 94 | u32 status; |
| 95 | |
| 96 | if (id < 0 || id >= TEGRA_NUM_POWERGATE) |
| 97 | return -EINVAL; |
| 98 | |
| 99 | status = pmc_read(PWRGATE_STATUS) & (1 << id); |
| 100 | return !!status; |
| 101 | } |
| 102 | |
| 103 | int tegra_powergate_remove_clamping(int id) |
| 104 | { |
| 105 | u32 mask; |
| 106 | |
| 107 | if (id < 0 || id >= TEGRA_NUM_POWERGATE) |
| 108 | return -EINVAL; |
| 109 | |
| 110 | /* |
| 111 | * Tegra 2 has a bug where PCIE and VDE clamping masks are |
| 112 | * swapped relatively to the partition ids |
| 113 | */ |
| 114 | if (id == TEGRA_POWERGATE_VDEC) |
| 115 | mask = (1 << TEGRA_POWERGATE_PCIE); |
| 116 | else if (id == TEGRA_POWERGATE_PCIE) |
| 117 | mask = (1 << TEGRA_POWERGATE_VDEC); |
| 118 | else |
| 119 | mask = (1 << id); |
| 120 | |
| 121 | pmc_write(mask, REMOVE_CLAMPING); |
| 122 | |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | /* Must be called with clk disabled, and returns with clk enabled */ |
| 127 | int tegra_powergate_sequence_power_up(int id, struct clk *clk) |
| 128 | { |
| 129 | int ret; |
| 130 | |
| 131 | tegra_periph_reset_assert(clk); |
| 132 | |
| 133 | ret = tegra_powergate_power_on(id); |
| 134 | if (ret) |
| 135 | goto err_power; |
| 136 | |
| 137 | ret = clk_enable(clk); |
| 138 | if (ret) |
| 139 | goto err_clk; |
| 140 | |
| 141 | udelay(10); |
| 142 | |
| 143 | ret = tegra_powergate_remove_clamping(id); |
| 144 | if (ret) |
| 145 | goto err_clamp; |
| 146 | |
| 147 | udelay(10); |
| 148 | tegra_periph_reset_deassert(clk); |
| 149 | |
| 150 | return 0; |
| 151 | |
| 152 | err_clamp: |
| 153 | clk_disable(clk); |
| 154 | err_clk: |
| 155 | tegra_powergate_power_off(id); |
| 156 | err_power: |
| 157 | return ret; |
| 158 | } |
| 159 | |
| 160 | #ifdef CONFIG_DEBUG_FS |
| 161 | |
| 162 | static const char * const powergate_name[] = { |
| 163 | [TEGRA_POWERGATE_CPU] = "cpu", |
| 164 | [TEGRA_POWERGATE_3D] = "3d", |
| 165 | [TEGRA_POWERGATE_VENC] = "venc", |
| 166 | [TEGRA_POWERGATE_VDEC] = "vdec", |
| 167 | [TEGRA_POWERGATE_PCIE] = "pcie", |
| 168 | [TEGRA_POWERGATE_L2] = "l2", |
| 169 | [TEGRA_POWERGATE_MPE] = "mpe", |
| 170 | }; |
| 171 | |
| 172 | static int powergate_show(struct seq_file *s, void *data) |
| 173 | { |
| 174 | int i; |
| 175 | |
| 176 | seq_printf(s, " powergate powered\n"); |
| 177 | seq_printf(s, "------------------\n"); |
| 178 | |
| 179 | for (i = 0; i < TEGRA_NUM_POWERGATE; i++) |
| 180 | seq_printf(s, " %9s %7s\n", powergate_name[i], |
| 181 | tegra_powergate_is_powered(i) ? "yes" : "no"); |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | static int powergate_open(struct inode *inode, struct file *file) |
| 186 | { |
| 187 | return single_open(file, powergate_show, inode->i_private); |
| 188 | } |
| 189 | |
| 190 | static const struct file_operations powergate_fops = { |
| 191 | .open = powergate_open, |
| 192 | .read = seq_read, |
| 193 | .llseek = seq_lseek, |
| 194 | .release = single_release, |
| 195 | }; |
| 196 | |
| 197 | static int __init powergate_debugfs_init(void) |
| 198 | { |
| 199 | struct dentry *d; |
| 200 | int err = -ENOMEM; |
| 201 | |
| 202 | d = debugfs_create_file("powergate", S_IRUGO, NULL, NULL, |
| 203 | &powergate_fops); |
| 204 | if (!d) |
| 205 | return -ENOMEM; |
| 206 | |
| 207 | return err; |
| 208 | } |
| 209 | |
| 210 | late_initcall(powergate_debugfs_init); |
| 211 | |
| 212 | #endif |