Commit f68ba691 authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Thierry Reding

drm/tegra: dc: Link DC1 to DC0 on Tegra20

Hardware reset isn't actually broken on Tegra20, but there is a
dependency on the first display controller to be taken out of reset for
the second to be enabled successfully. Model this dependency using a PM
device link.
Signed-off-by: default avatarDmitry Osipenko <digetx@gmail.com>
[treding@nvidia.com: minor cleanups, extend commit message]
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 39f55c61
......@@ -1882,7 +1882,7 @@ static const struct tegra_dc_soc_info tegra20_dc_soc_info = {
.supports_blending = false,
.pitch_align = 8,
.has_powergate = false,
.broken_reset = true,
.coupled_pm = true,
.has_nvdisplay = false,
.num_primary_formats = ARRAY_SIZE(tegra20_primary_formats),
.primary_formats = tegra20_primary_formats,
......@@ -1898,7 +1898,7 @@ static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
.supports_blending = false,
.pitch_align = 8,
.has_powergate = false,
.broken_reset = false,
.coupled_pm = false,
.has_nvdisplay = false,
.num_primary_formats = ARRAY_SIZE(tegra20_primary_formats),
.primary_formats = tegra20_primary_formats,
......@@ -1914,7 +1914,7 @@ static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
.supports_blending = false,
.pitch_align = 64,
.has_powergate = true,
.broken_reset = false,
.coupled_pm = false,
.has_nvdisplay = false,
.num_primary_formats = ARRAY_SIZE(tegra114_primary_formats),
.primary_formats = tegra114_primary_formats,
......@@ -1930,7 +1930,7 @@ static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
.supports_blending = true,
.pitch_align = 64,
.has_powergate = true,
.broken_reset = false,
.coupled_pm = false,
.has_nvdisplay = false,
.num_primary_formats = ARRAY_SIZE(tegra124_primary_formats),
.primary_formats = tegra114_primary_formats,
......@@ -1946,7 +1946,7 @@ static const struct tegra_dc_soc_info tegra210_dc_soc_info = {
.supports_blending = true,
.pitch_align = 64,
.has_powergate = true,
.broken_reset = false,
.coupled_pm = false,
.has_nvdisplay = false,
.num_primary_formats = ARRAY_SIZE(tegra114_primary_formats),
.primary_formats = tegra114_primary_formats,
......@@ -1996,7 +1996,7 @@ static const struct tegra_dc_soc_info tegra186_dc_soc_info = {
.supports_blending = true,
.pitch_align = 64,
.has_powergate = false,
.broken_reset = false,
.coupled_pm = false,
.has_nvdisplay = true,
.wgrps = tegra186_dc_wgrps,
.num_wgrps = ARRAY_SIZE(tegra186_dc_wgrps),
......@@ -2064,6 +2064,43 @@ static int tegra_dc_parse_dt(struct tegra_dc *dc)
return 0;
}
static int tegra_dc_match_by_pipe(struct device *dev, void *data)
{
struct tegra_dc *dc = dev_get_drvdata(dev);
unsigned int pipe = (unsigned long)data;
return dc->pipe == pipe;
}
static int tegra_dc_couple(struct tegra_dc *dc)
{
/*
* On Tegra20, DC1 requires DC0 to be taken out of reset in order to
* be enabled, otherwise CPU hangs on writing to CMD_DISPLAY_COMMAND /
* POWER_CONTROL registers during CRTC enabling.
*/
if (dc->soc->coupled_pm && dc->pipe == 1) {
u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE;
struct device_link *link;
struct device *partner;
partner = driver_find_device(dc->dev->driver, NULL, 0,
tegra_dc_match_by_pipe);
if (!partner)
return -EPROBE_DEFER;
link = device_link_add(dc->dev, partner, flags);
if (!link) {
dev_err(dc->dev, "failed to link controllers\n");
return -EINVAL;
}
dev_dbg(dc->dev, "coupled to %s\n", dev_name(partner));
}
return 0;
}
static int tegra_dc_probe(struct platform_device *pdev)
{
struct resource *regs;
......@@ -2083,6 +2120,10 @@ static int tegra_dc_probe(struct platform_device *pdev)
if (err < 0)
return err;
err = tegra_dc_couple(dc);
if (err < 0)
return err;
dc->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(dc->clk)) {
dev_err(&pdev->dev, "failed to get clock\n");
......@@ -2096,21 +2137,19 @@ static int tegra_dc_probe(struct platform_device *pdev)
}
/* assert reset and disable clock */
if (!dc->soc->broken_reset) {
err = clk_prepare_enable(dc->clk);
if (err < 0)
return err;
err = clk_prepare_enable(dc->clk);
if (err < 0)
return err;
usleep_range(2000, 4000);
usleep_range(2000, 4000);
err = reset_control_assert(dc->rst);
if (err < 0)
return err;
err = reset_control_assert(dc->rst);
if (err < 0)
return err;
usleep_range(2000, 4000);
usleep_range(2000, 4000);
clk_disable_unprepare(dc->clk);
}
clk_disable_unprepare(dc->clk);
if (dc->soc->has_powergate) {
if (dc->pipe == 0)
......@@ -2184,12 +2223,10 @@ static int tegra_dc_suspend(struct device *dev)
struct tegra_dc *dc = dev_get_drvdata(dev);
int err;
if (!dc->soc->broken_reset) {
err = reset_control_assert(dc->rst);
if (err < 0) {
dev_err(dev, "failed to assert reset: %d\n", err);
return err;
}
err = reset_control_assert(dc->rst);
if (err < 0) {
dev_err(dev, "failed to assert reset: %d\n", err);
return err;
}
if (dc->soc->has_powergate)
......@@ -2219,13 +2256,10 @@ static int tegra_dc_resume(struct device *dev)
return err;
}
if (!dc->soc->broken_reset) {
err = reset_control_deassert(dc->rst);
if (err < 0) {
dev_err(dev,
"failed to deassert reset: %d\n", err);
return err;
}
err = reset_control_deassert(dc->rst);
if (err < 0) {
dev_err(dev, "failed to deassert reset: %d\n", err);
return err;
}
}
......
......@@ -58,7 +58,7 @@ struct tegra_dc_soc_info {
bool supports_blending;
unsigned int pitch_align;
bool has_powergate;
bool broken_reset;
bool coupled_pm;
bool has_nvdisplay;
const struct tegra_windowgroup_soc *wgrps;
unsigned int num_wgrps;
......
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