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linux-next/arch/arm/mach-tegra/powergate.c
Thierry Reding 9d4450ae87 ARM: tegra: Add IO rail support
Add tegra_io_rail_power_off() and tegra_io_rail_power_on() functions to
put IO rails into or out of deep powerdown mode, respectively.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
2013-12-16 14:03:09 -07:00

514 lines
11 KiB
C

/*
* drivers/powergate/tegra-powergate.c
*
* Copyright (c) 2010 Google, Inc
*
* Author:
* Colin Cross <ccross@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/export.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/reset.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/clk/tegra.h>
#include <linux/tegra-powergate.h>
#include "fuse.h"
#include "iomap.h"
#define DPD_SAMPLE 0x020
#define DPD_SAMPLE_ENABLE (1 << 0)
#define DPD_SAMPLE_DISABLE (0 << 0)
#define PWRGATE_TOGGLE 0x30
#define PWRGATE_TOGGLE_START (1 << 8)
#define REMOVE_CLAMPING 0x34
#define PWRGATE_STATUS 0x38
#define IO_DPD_REQ 0x1b8
#define IO_DPD_REQ_CODE_IDLE (0 << 30)
#define IO_DPD_REQ_CODE_OFF (1 << 30)
#define IO_DPD_REQ_CODE_ON (2 << 30)
#define IO_DPD_REQ_CODE_MASK (3 << 30)
#define IO_DPD_STATUS 0x1bc
#define IO_DPD2_REQ 0x1c0
#define IO_DPD2_STATUS 0x1c4
#define SEL_DPD_TIM 0x1c8
#define GPU_RG_CNTRL 0x2d4
static int tegra_num_powerdomains;
static int tegra_num_cpu_domains;
static const u8 *tegra_cpu_domains;
static const u8 tegra30_cpu_domains[] = {
TEGRA_POWERGATE_CPU,
TEGRA_POWERGATE_CPU1,
TEGRA_POWERGATE_CPU2,
TEGRA_POWERGATE_CPU3,
};
static const u8 tegra114_cpu_domains[] = {
TEGRA_POWERGATE_CPU0,
TEGRA_POWERGATE_CPU1,
TEGRA_POWERGATE_CPU2,
TEGRA_POWERGATE_CPU3,
};
static const u8 tegra124_cpu_domains[] = {
TEGRA_POWERGATE_CPU0,
TEGRA_POWERGATE_CPU1,
TEGRA_POWERGATE_CPU2,
TEGRA_POWERGATE_CPU3,
};
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 0;
}
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_powerdomains)
return -EINVAL;
return tegra_powergate_set(id, true);
}
int tegra_powergate_power_off(int id)
{
if (id < 0 || id >= tegra_num_powerdomains)
return -EINVAL;
return tegra_powergate_set(id, false);
}
EXPORT_SYMBOL(tegra_powergate_power_off);
int tegra_powergate_is_powered(int id)
{
u32 status;
if (id < 0 || id >= tegra_num_powerdomains)
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_powerdomains)
return -EINVAL;
/*
* The Tegra124 GPU has a separate register (with different semantics)
* to remove clamps.
*/
if (tegra_chip_id == TEGRA124) {
if (id == TEGRA_POWERGATE_3D) {
pmc_write(0, GPU_RG_CNTRL);
return 0;
}
}
/*
* 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;
}
EXPORT_SYMBOL(tegra_powergate_remove_clamping);
/* Must be called with clk disabled, and returns with clk enabled */
int tegra_powergate_sequence_power_up(int id, struct clk *clk,
struct reset_control *rst)
{
int ret;
reset_control_assert(rst);
ret = tegra_powergate_power_on(id);
if (ret)
goto err_power;
ret = clk_prepare_enable(clk);
if (ret)
goto err_clk;
udelay(10);
ret = tegra_powergate_remove_clamping(id);
if (ret)
goto err_clamp;
udelay(10);
reset_control_deassert(rst);
return 0;
err_clamp:
clk_disable_unprepare(clk);
err_clk:
tegra_powergate_power_off(id);
err_power:
return ret;
}
EXPORT_SYMBOL(tegra_powergate_sequence_power_up);
int tegra_cpu_powergate_id(int cpuid)
{
if (cpuid > 0 && cpuid < tegra_num_cpu_domains)
return tegra_cpu_domains[cpuid];
return -EINVAL;
}
int __init tegra_powergate_init(void)
{
switch (tegra_chip_id) {
case TEGRA20:
tegra_num_powerdomains = 7;
break;
case TEGRA30:
tegra_num_powerdomains = 14;
tegra_num_cpu_domains = 4;
tegra_cpu_domains = tegra30_cpu_domains;
break;
case TEGRA114:
tegra_num_powerdomains = 23;
tegra_num_cpu_domains = 4;
tegra_cpu_domains = tegra114_cpu_domains;
break;
case TEGRA124:
tegra_num_powerdomains = 25;
tegra_num_cpu_domains = 4;
tegra_cpu_domains = tegra124_cpu_domains;
break;
default:
/* Unknown Tegra variant. Disable powergating */
tegra_num_powerdomains = 0;
break;
}
return 0;
}
#ifdef CONFIG_DEBUG_FS
static const char * const *powergate_name;
static const char * const powergate_name_t20[] = {
[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 const char * const powergate_name_t30[] = {
[TEGRA_POWERGATE_CPU] = "cpu0",
[TEGRA_POWERGATE_3D] = "3d0",
[TEGRA_POWERGATE_VENC] = "venc",
[TEGRA_POWERGATE_VDEC] = "vdec",
[TEGRA_POWERGATE_PCIE] = "pcie",
[TEGRA_POWERGATE_L2] = "l2",
[TEGRA_POWERGATE_MPE] = "mpe",
[TEGRA_POWERGATE_HEG] = "heg",
[TEGRA_POWERGATE_SATA] = "sata",
[TEGRA_POWERGATE_CPU1] = "cpu1",
[TEGRA_POWERGATE_CPU2] = "cpu2",
[TEGRA_POWERGATE_CPU3] = "cpu3",
[TEGRA_POWERGATE_CELP] = "celp",
[TEGRA_POWERGATE_3D1] = "3d1",
};
static const char * const powergate_name_t114[] = {
[TEGRA_POWERGATE_CPU] = "crail",
[TEGRA_POWERGATE_3D] = "3d",
[TEGRA_POWERGATE_VENC] = "venc",
[TEGRA_POWERGATE_VDEC] = "vdec",
[TEGRA_POWERGATE_MPE] = "mpe",
[TEGRA_POWERGATE_HEG] = "heg",
[TEGRA_POWERGATE_CPU1] = "cpu1",
[TEGRA_POWERGATE_CPU2] = "cpu2",
[TEGRA_POWERGATE_CPU3] = "cpu3",
[TEGRA_POWERGATE_CELP] = "celp",
[TEGRA_POWERGATE_CPU0] = "cpu0",
[TEGRA_POWERGATE_C0NC] = "c0nc",
[TEGRA_POWERGATE_C1NC] = "c1nc",
[TEGRA_POWERGATE_DIS] = "dis",
[TEGRA_POWERGATE_DISB] = "disb",
[TEGRA_POWERGATE_XUSBA] = "xusba",
[TEGRA_POWERGATE_XUSBB] = "xusbb",
[TEGRA_POWERGATE_XUSBC] = "xusbc",
};
static const char * const powergate_name_t124[] = {
[TEGRA_POWERGATE_CPU] = "crail",
[TEGRA_POWERGATE_3D] = "3d",
[TEGRA_POWERGATE_VENC] = "venc",
[TEGRA_POWERGATE_PCIE] = "pcie",
[TEGRA_POWERGATE_VDEC] = "vdec",
[TEGRA_POWERGATE_L2] = "l2",
[TEGRA_POWERGATE_MPE] = "mpe",
[TEGRA_POWERGATE_HEG] = "heg",
[TEGRA_POWERGATE_SATA] = "sata",
[TEGRA_POWERGATE_CPU1] = "cpu1",
[TEGRA_POWERGATE_CPU2] = "cpu2",
[TEGRA_POWERGATE_CPU3] = "cpu3",
[TEGRA_POWERGATE_CELP] = "celp",
[TEGRA_POWERGATE_CPU0] = "cpu0",
[TEGRA_POWERGATE_C0NC] = "c0nc",
[TEGRA_POWERGATE_C1NC] = "c1nc",
[TEGRA_POWERGATE_SOR] = "sor",
[TEGRA_POWERGATE_DIS] = "dis",
[TEGRA_POWERGATE_DISB] = "disb",
[TEGRA_POWERGATE_XUSBA] = "xusba",
[TEGRA_POWERGATE_XUSBB] = "xusbb",
[TEGRA_POWERGATE_XUSBC] = "xusbc",
[TEGRA_POWERGATE_VIC] = "vic",
[TEGRA_POWERGATE_IRAM] = "iram",
};
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_powerdomains; i++) {
if (!powergate_name[i])
continue;
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,
};
int __init tegra_powergate_debugfs_init(void)
{
struct dentry *d;
switch (tegra_chip_id) {
case TEGRA20:
powergate_name = powergate_name_t20;
break;
case TEGRA30:
powergate_name = powergate_name_t30;
break;
case TEGRA114:
powergate_name = powergate_name_t114;
break;
case TEGRA124:
powergate_name = powergate_name_t124;
break;
}
if (powergate_name) {
d = debugfs_create_file("powergate", S_IRUGO, NULL, NULL,
&powergate_fops);
if (!d)
return -ENOMEM;
}
return 0;
}
#endif
static int tegra_io_rail_prepare(int id, unsigned long *request,
unsigned long *status, unsigned int *bit)
{
unsigned long rate, value;
struct clk *clk;
*bit = id % 32;
/*
* There are two sets of 30 bits to select IO rails, but bits 30 and
* 31 are control bits rather than IO rail selection bits.
*/
if (id > 63 || *bit == 30 || *bit == 31)
return -EINVAL;
if (id < 32) {
*status = IO_DPD_STATUS;
*request = IO_DPD_REQ;
} else {
*status = IO_DPD2_STATUS;
*request = IO_DPD2_REQ;
}
clk = clk_get_sys(NULL, "pclk");
if (IS_ERR(clk))
return PTR_ERR(clk);
rate = clk_get_rate(clk);
clk_put(clk);
pmc_write(DPD_SAMPLE_ENABLE, DPD_SAMPLE);
/* must be at least 200 ns, in APB (PCLK) clock cycles */
value = DIV_ROUND_UP(1000000000, rate);
value = DIV_ROUND_UP(200, value);
pmc_write(value, SEL_DPD_TIM);
return 0;
}
static int tegra_io_rail_poll(unsigned long offset, unsigned long mask,
unsigned long val, unsigned long timeout)
{
unsigned long value;
timeout = jiffies + msecs_to_jiffies(timeout);
while (time_after(timeout, jiffies)) {
value = pmc_read(offset);
if ((value & mask) == val)
return 0;
usleep_range(250, 1000);
}
return -ETIMEDOUT;
}
static void tegra_io_rail_unprepare(void)
{
pmc_write(DPD_SAMPLE_DISABLE, DPD_SAMPLE);
}
int tegra_io_rail_power_on(int id)
{
unsigned long request, status, value;
unsigned int bit, mask;
int err;
err = tegra_io_rail_prepare(id, &request, &status, &bit);
if (err < 0)
return err;
mask = 1 << bit;
value = pmc_read(request);
value |= mask;
value &= ~IO_DPD_REQ_CODE_MASK;
value |= IO_DPD_REQ_CODE_OFF;
pmc_write(value, request);
err = tegra_io_rail_poll(status, mask, 0, 250);
if (err < 0)
return err;
tegra_io_rail_unprepare();
return 0;
}
int tegra_io_rail_power_off(int id)
{
unsigned long request, status, value;
unsigned int bit, mask;
int err;
err = tegra_io_rail_prepare(id, &request, &status, &bit);
if (err < 0)
return err;
mask = 1 << bit;
value = pmc_read(request);
value |= mask;
value &= ~IO_DPD_REQ_CODE_MASK;
value |= IO_DPD_REQ_CODE_ON;
pmc_write(value, request);
err = tegra_io_rail_poll(status, mask, mask, 250);
if (err < 0)
return err;
tegra_io_rail_unprepare();
return 0;
}