linux/drivers/gpu/host1x/mipi.c
Thierry Reding 87904c3e82 drm/tegra: dsi: Enhance runtime power management
The MIPI DSI output on Tegra SoCs requires some external logic to
calibrate the MIPI pads before a video signal can be transmitted. This
MIPI calibration logic requires to be powered on while the MIPI pads are
being used, which is currently done as part of the DSI driver's probe
implementation.

This is suboptimal because it will leave the MIPI calibration logic
powered up even if the DSI output is never used.

On Tegra114 and earlier this behaviour also causes the driver to hang
while trying to power up the MIPI calibration logic because the power
partition that contains the MIPI calibration logic will be powered on
by the display controller at output pipeline configuration time. Thus
the power up sequence for the MIPI calibration logic happens before
it's power partition is guaranteed to be enabled.

Fix this by splitting up the API into a request/free pair of functions
that manage the runtime dependency between the DSI and the calibration
modules (no registers are accessed) and a set of enable, calibrate and
disable functions that program the MIPI calibration logic at points in
time where the power partition is really enabled.

While at it, make sure that the runtime power management also works in
ganged mode, which is currently also broken.

Reported-by: Jonathan Hunter <jonathanh@nvidia.com>
Tested-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2016-08-24 15:58:57 +02:00

554 lines
14 KiB
C

/*
* Copyright (C) 2013 NVIDIA Corporation
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/host1x.h>
#include <linux/io.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "dev.h"
#define MIPI_CAL_CTRL 0x00
#define MIPI_CAL_CTRL_NOISE_FILTER(x) (((x) & 0xf) << 26)
#define MIPI_CAL_CTRL_PRESCALE(x) (((x) & 0x3) << 24)
#define MIPI_CAL_CTRL_CLKEN_OVR (1 << 4)
#define MIPI_CAL_CTRL_START (1 << 0)
#define MIPI_CAL_AUTOCAL_CTRL 0x01
#define MIPI_CAL_STATUS 0x02
#define MIPI_CAL_STATUS_DONE (1 << 16)
#define MIPI_CAL_STATUS_ACTIVE (1 << 0)
#define MIPI_CAL_CONFIG_CSIA 0x05
#define MIPI_CAL_CONFIG_CSIB 0x06
#define MIPI_CAL_CONFIG_CSIC 0x07
#define MIPI_CAL_CONFIG_CSID 0x08
#define MIPI_CAL_CONFIG_CSIE 0x09
#define MIPI_CAL_CONFIG_CSIF 0x0a
#define MIPI_CAL_CONFIG_DSIA 0x0e
#define MIPI_CAL_CONFIG_DSIB 0x0f
#define MIPI_CAL_CONFIG_DSIC 0x10
#define MIPI_CAL_CONFIG_DSID 0x11
#define MIPI_CAL_CONFIG_DSIA_CLK 0x19
#define MIPI_CAL_CONFIG_DSIB_CLK 0x1a
#define MIPI_CAL_CONFIG_CSIAB_CLK 0x1b
#define MIPI_CAL_CONFIG_DSIC_CLK 0x1c
#define MIPI_CAL_CONFIG_CSICD_CLK 0x1c
#define MIPI_CAL_CONFIG_DSID_CLK 0x1d
#define MIPI_CAL_CONFIG_CSIE_CLK 0x1d
/* for data and clock lanes */
#define MIPI_CAL_CONFIG_SELECT (1 << 21)
/* for data lanes */
#define MIPI_CAL_CONFIG_HSPDOS(x) (((x) & 0x1f) << 16)
#define MIPI_CAL_CONFIG_HSPUOS(x) (((x) & 0x1f) << 8)
#define MIPI_CAL_CONFIG_TERMOS(x) (((x) & 0x1f) << 0)
/* for clock lanes */
#define MIPI_CAL_CONFIG_HSCLKPDOSD(x) (((x) & 0x1f) << 8)
#define MIPI_CAL_CONFIG_HSCLKPUOSD(x) (((x) & 0x1f) << 0)
#define MIPI_CAL_BIAS_PAD_CFG0 0x16
#define MIPI_CAL_BIAS_PAD_PDVCLAMP (1 << 1)
#define MIPI_CAL_BIAS_PAD_E_VCLAMP_REF (1 << 0)
#define MIPI_CAL_BIAS_PAD_CFG1 0x17
#define MIPI_CAL_BIAS_PAD_DRV_DN_REF(x) (((x) & 0x7) << 16)
#define MIPI_CAL_BIAS_PAD_DRV_UP_REF(x) (((x) & 0x7) << 8)
#define MIPI_CAL_BIAS_PAD_CFG2 0x18
#define MIPI_CAL_BIAS_PAD_VCLAMP(x) (((x) & 0x7) << 16)
#define MIPI_CAL_BIAS_PAD_VAUXP(x) (((x) & 0x7) << 4)
#define MIPI_CAL_BIAS_PAD_PDVREG (1 << 1)
struct tegra_mipi_pad {
unsigned long data;
unsigned long clk;
};
struct tegra_mipi_soc {
bool has_clk_lane;
const struct tegra_mipi_pad *pads;
unsigned int num_pads;
bool clock_enable_override;
bool needs_vclamp_ref;
/* bias pad configuration settings */
u8 pad_drive_down_ref;
u8 pad_drive_up_ref;
u8 pad_vclamp_level;
u8 pad_vauxp_level;
/* calibration settings for data lanes */
u8 hspdos;
u8 hspuos;
u8 termos;
/* calibration settings for clock lanes */
u8 hsclkpdos;
u8 hsclkpuos;
};
struct tegra_mipi {
const struct tegra_mipi_soc *soc;
struct device *dev;
void __iomem *regs;
struct mutex lock;
struct clk *clk;
unsigned long usage_count;
};
struct tegra_mipi_device {
struct platform_device *pdev;
struct tegra_mipi *mipi;
struct device *device;
unsigned long pads;
};
static inline u32 tegra_mipi_readl(struct tegra_mipi *mipi,
unsigned long offset)
{
return readl(mipi->regs + (offset << 2));
}
static inline void tegra_mipi_writel(struct tegra_mipi *mipi, u32 value,
unsigned long offset)
{
writel(value, mipi->regs + (offset << 2));
}
static int tegra_mipi_power_up(struct tegra_mipi *mipi)
{
u32 value;
int err;
err = clk_enable(mipi->clk);
if (err < 0)
return err;
value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG0);
value &= ~MIPI_CAL_BIAS_PAD_PDVCLAMP;
if (mipi->soc->needs_vclamp_ref)
value |= MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;
tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG0);
value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG2);
value &= ~MIPI_CAL_BIAS_PAD_PDVREG;
tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG2);
clk_disable(mipi->clk);
return 0;
}
static int tegra_mipi_power_down(struct tegra_mipi *mipi)
{
u32 value;
int err;
err = clk_enable(mipi->clk);
if (err < 0)
return err;
/*
* The MIPI_CAL_BIAS_PAD_PDVREG controls a voltage regulator that
* supplies the DSI pads. This must be kept enabled until none of the
* DSI lanes are used anymore.
*/
value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG2);
value |= MIPI_CAL_BIAS_PAD_PDVREG;
tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG2);
/*
* MIPI_CAL_BIAS_PAD_PDVCLAMP and MIPI_CAL_BIAS_PAD_E_VCLAMP_REF
* control a regulator that supplies current to the pre-driver logic.
* Powering down this regulator causes DSI to fail, so it must remain
* powered on until none of the DSI lanes are used anymore.
*/
value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG0);
if (mipi->soc->needs_vclamp_ref)
value &= ~MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;
value |= MIPI_CAL_BIAS_PAD_PDVCLAMP;
tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG0);
return 0;
}
struct tegra_mipi_device *tegra_mipi_request(struct device *device)
{
struct device_node *np = device->of_node;
struct tegra_mipi_device *dev;
struct of_phandle_args args;
int err;
err = of_parse_phandle_with_args(np, "nvidia,mipi-calibrate",
"#nvidia,mipi-calibrate-cells", 0,
&args);
if (err < 0)
return ERR_PTR(err);
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
err = -ENOMEM;
goto out;
}
dev->pdev = of_find_device_by_node(args.np);
if (!dev->pdev) {
err = -ENODEV;
goto free;
}
dev->mipi = platform_get_drvdata(dev->pdev);
if (!dev->mipi) {
err = -EPROBE_DEFER;
goto put;
}
of_node_put(args.np);
dev->pads = args.args[0];
dev->device = device;
return dev;
put:
platform_device_put(dev->pdev);
free:
kfree(dev);
out:
of_node_put(args.np);
return ERR_PTR(err);
}
EXPORT_SYMBOL(tegra_mipi_request);
void tegra_mipi_free(struct tegra_mipi_device *device)
{
platform_device_put(device->pdev);
kfree(device);
}
EXPORT_SYMBOL(tegra_mipi_free);
int tegra_mipi_enable(struct tegra_mipi_device *dev)
{
int err = 0;
mutex_lock(&dev->mipi->lock);
if (dev->mipi->usage_count++ == 0)
err = tegra_mipi_power_up(dev->mipi);
mutex_unlock(&dev->mipi->lock);
return err;
}
EXPORT_SYMBOL(tegra_mipi_enable);
int tegra_mipi_disable(struct tegra_mipi_device *dev)
{
int err = 0;
mutex_lock(&dev->mipi->lock);
if (--dev->mipi->usage_count == 0)
err = tegra_mipi_power_down(dev->mipi);
mutex_unlock(&dev->mipi->lock);
return err;
}
EXPORT_SYMBOL(tegra_mipi_disable);
static int tegra_mipi_wait(struct tegra_mipi *mipi)
{
unsigned long timeout = jiffies + msecs_to_jiffies(250);
u32 value;
while (time_before(jiffies, timeout)) {
value = tegra_mipi_readl(mipi, MIPI_CAL_STATUS);
if ((value & MIPI_CAL_STATUS_ACTIVE) == 0 &&
(value & MIPI_CAL_STATUS_DONE) != 0)
return 0;
usleep_range(10, 50);
}
return -ETIMEDOUT;
}
int tegra_mipi_calibrate(struct tegra_mipi_device *device)
{
const struct tegra_mipi_soc *soc = device->mipi->soc;
unsigned int i;
u32 value;
int err;
err = clk_enable(device->mipi->clk);
if (err < 0)
return err;
mutex_lock(&device->mipi->lock);
value = MIPI_CAL_BIAS_PAD_DRV_DN_REF(soc->pad_drive_down_ref) |
MIPI_CAL_BIAS_PAD_DRV_UP_REF(soc->pad_drive_up_ref);
tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG1);
value = tegra_mipi_readl(device->mipi, MIPI_CAL_BIAS_PAD_CFG2);
value &= ~MIPI_CAL_BIAS_PAD_VCLAMP(0x7);
value &= ~MIPI_CAL_BIAS_PAD_VAUXP(0x7);
value |= MIPI_CAL_BIAS_PAD_VCLAMP(soc->pad_vclamp_level);
value |= MIPI_CAL_BIAS_PAD_VAUXP(soc->pad_vauxp_level);
tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG2);
for (i = 0; i < soc->num_pads; i++) {
u32 clk = 0, data = 0;
if (device->pads & BIT(i)) {
data = MIPI_CAL_CONFIG_SELECT |
MIPI_CAL_CONFIG_HSPDOS(soc->hspdos) |
MIPI_CAL_CONFIG_HSPUOS(soc->hspuos) |
MIPI_CAL_CONFIG_TERMOS(soc->termos);
clk = MIPI_CAL_CONFIG_SELECT |
MIPI_CAL_CONFIG_HSCLKPDOSD(soc->hsclkpdos) |
MIPI_CAL_CONFIG_HSCLKPUOSD(soc->hsclkpuos);
}
tegra_mipi_writel(device->mipi, data, soc->pads[i].data);
if (soc->has_clk_lane && soc->pads[i].clk != 0)
tegra_mipi_writel(device->mipi, clk, soc->pads[i].clk);
}
value = tegra_mipi_readl(device->mipi, MIPI_CAL_CTRL);
value &= ~MIPI_CAL_CTRL_NOISE_FILTER(0xf);
value &= ~MIPI_CAL_CTRL_PRESCALE(0x3);
value |= MIPI_CAL_CTRL_NOISE_FILTER(0xa);
value |= MIPI_CAL_CTRL_PRESCALE(0x2);
if (!soc->clock_enable_override)
value &= ~MIPI_CAL_CTRL_CLKEN_OVR;
else
value |= MIPI_CAL_CTRL_CLKEN_OVR;
tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);
/* clear any pending status bits */
value = tegra_mipi_readl(device->mipi, MIPI_CAL_STATUS);
tegra_mipi_writel(device->mipi, value, MIPI_CAL_STATUS);
value = tegra_mipi_readl(device->mipi, MIPI_CAL_CTRL);
value |= MIPI_CAL_CTRL_START;
tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);
err = tegra_mipi_wait(device->mipi);
mutex_unlock(&device->mipi->lock);
clk_disable(device->mipi->clk);
return err;
}
EXPORT_SYMBOL(tegra_mipi_calibrate);
static const struct tegra_mipi_pad tegra114_mipi_pads[] = {
{ .data = MIPI_CAL_CONFIG_CSIA },
{ .data = MIPI_CAL_CONFIG_CSIB },
{ .data = MIPI_CAL_CONFIG_CSIC },
{ .data = MIPI_CAL_CONFIG_CSID },
{ .data = MIPI_CAL_CONFIG_CSIE },
{ .data = MIPI_CAL_CONFIG_DSIA },
{ .data = MIPI_CAL_CONFIG_DSIB },
{ .data = MIPI_CAL_CONFIG_DSIC },
{ .data = MIPI_CAL_CONFIG_DSID },
};
static const struct tegra_mipi_soc tegra114_mipi_soc = {
.has_clk_lane = false,
.pads = tegra114_mipi_pads,
.num_pads = ARRAY_SIZE(tegra114_mipi_pads),
.clock_enable_override = true,
.needs_vclamp_ref = true,
.pad_drive_down_ref = 0x2,
.pad_drive_up_ref = 0x0,
.pad_vclamp_level = 0x0,
.pad_vauxp_level = 0x0,
.hspdos = 0x0,
.hspuos = 0x4,
.termos = 0x5,
.hsclkpdos = 0x0,
.hsclkpuos = 0x4,
};
static const struct tegra_mipi_pad tegra124_mipi_pads[] = {
{ .data = MIPI_CAL_CONFIG_CSIA, .clk = MIPI_CAL_CONFIG_CSIAB_CLK },
{ .data = MIPI_CAL_CONFIG_CSIB, .clk = MIPI_CAL_CONFIG_CSIAB_CLK },
{ .data = MIPI_CAL_CONFIG_CSIC, .clk = MIPI_CAL_CONFIG_CSICD_CLK },
{ .data = MIPI_CAL_CONFIG_CSID, .clk = MIPI_CAL_CONFIG_CSICD_CLK },
{ .data = MIPI_CAL_CONFIG_CSIE, .clk = MIPI_CAL_CONFIG_CSIE_CLK },
{ .data = MIPI_CAL_CONFIG_DSIA, .clk = MIPI_CAL_CONFIG_DSIA_CLK },
{ .data = MIPI_CAL_CONFIG_DSIB, .clk = MIPI_CAL_CONFIG_DSIB_CLK },
};
static const struct tegra_mipi_soc tegra124_mipi_soc = {
.has_clk_lane = true,
.pads = tegra124_mipi_pads,
.num_pads = ARRAY_SIZE(tegra124_mipi_pads),
.clock_enable_override = true,
.needs_vclamp_ref = true,
.pad_drive_down_ref = 0x2,
.pad_drive_up_ref = 0x0,
.pad_vclamp_level = 0x0,
.pad_vauxp_level = 0x0,
.hspdos = 0x0,
.hspuos = 0x0,
.termos = 0x0,
.hsclkpdos = 0x1,
.hsclkpuos = 0x2,
};
static const struct tegra_mipi_soc tegra132_mipi_soc = {
.has_clk_lane = true,
.pads = tegra124_mipi_pads,
.num_pads = ARRAY_SIZE(tegra124_mipi_pads),
.clock_enable_override = false,
.needs_vclamp_ref = false,
.pad_drive_down_ref = 0x0,
.pad_drive_up_ref = 0x3,
.pad_vclamp_level = 0x0,
.pad_vauxp_level = 0x0,
.hspdos = 0x0,
.hspuos = 0x0,
.termos = 0x0,
.hsclkpdos = 0x3,
.hsclkpuos = 0x2,
};
static const struct tegra_mipi_pad tegra210_mipi_pads[] = {
{ .data = MIPI_CAL_CONFIG_CSIA, .clk = 0 },
{ .data = MIPI_CAL_CONFIG_CSIB, .clk = 0 },
{ .data = MIPI_CAL_CONFIG_CSIC, .clk = 0 },
{ .data = MIPI_CAL_CONFIG_CSID, .clk = 0 },
{ .data = MIPI_CAL_CONFIG_CSIE, .clk = 0 },
{ .data = MIPI_CAL_CONFIG_CSIF, .clk = 0 },
{ .data = MIPI_CAL_CONFIG_DSIA, .clk = MIPI_CAL_CONFIG_DSIA_CLK },
{ .data = MIPI_CAL_CONFIG_DSIB, .clk = MIPI_CAL_CONFIG_DSIB_CLK },
{ .data = MIPI_CAL_CONFIG_DSIC, .clk = MIPI_CAL_CONFIG_DSIC_CLK },
{ .data = MIPI_CAL_CONFIG_DSID, .clk = MIPI_CAL_CONFIG_DSID_CLK },
};
static const struct tegra_mipi_soc tegra210_mipi_soc = {
.has_clk_lane = true,
.pads = tegra210_mipi_pads,
.num_pads = ARRAY_SIZE(tegra210_mipi_pads),
.clock_enable_override = true,
.needs_vclamp_ref = false,
.pad_drive_down_ref = 0x0,
.pad_drive_up_ref = 0x3,
.pad_vclamp_level = 0x1,
.pad_vauxp_level = 0x1,
.hspdos = 0x0,
.hspuos = 0x2,
.termos = 0x0,
.hsclkpdos = 0x0,
.hsclkpuos = 0x2,
};
static const struct of_device_id tegra_mipi_of_match[] = {
{ .compatible = "nvidia,tegra114-mipi", .data = &tegra114_mipi_soc },
{ .compatible = "nvidia,tegra124-mipi", .data = &tegra124_mipi_soc },
{ .compatible = "nvidia,tegra132-mipi", .data = &tegra132_mipi_soc },
{ .compatible = "nvidia,tegra210-mipi", .data = &tegra210_mipi_soc },
{ },
};
static int tegra_mipi_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
struct tegra_mipi *mipi;
struct resource *res;
int err;
match = of_match_node(tegra_mipi_of_match, pdev->dev.of_node);
if (!match)
return -ENODEV;
mipi = devm_kzalloc(&pdev->dev, sizeof(*mipi), GFP_KERNEL);
if (!mipi)
return -ENOMEM;
mipi->soc = match->data;
mipi->dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mipi->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(mipi->regs))
return PTR_ERR(mipi->regs);
mutex_init(&mipi->lock);
mipi->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(mipi->clk)) {
dev_err(&pdev->dev, "failed to get clock\n");
return PTR_ERR(mipi->clk);
}
err = clk_prepare(mipi->clk);
if (err < 0)
return err;
platform_set_drvdata(pdev, mipi);
return 0;
}
static int tegra_mipi_remove(struct platform_device *pdev)
{
struct tegra_mipi *mipi = platform_get_drvdata(pdev);
clk_unprepare(mipi->clk);
return 0;
}
struct platform_driver tegra_mipi_driver = {
.driver = {
.name = "tegra-mipi",
.of_match_table = tegra_mipi_of_match,
},
.probe = tegra_mipi_probe,
.remove = tegra_mipi_remove,
};