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Date: Thu, 23 Jul 2020 17:48:51 +0530
From: Krishna Yarlagadda <kyarlagadda@...dia.com>
To: <digetx@...il.com>, <linux-i2c@...r.kernel.org>,
<thierry.reding@...il.com>
CC: <jonathanh@...dia.com>, <linux-tegra@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <ldewangan@...dia.com>,
<smohammed@...dia.com>, <rgumasta@...dia.com>,
Krishna Yarlagadda <kyarlagadda@...dia.com>
Subject: [PATCH 5/7] i2c: tegra: enable second level clock gating
Enable Second Level Clock Gating feature for supported chips.
With SLCG enabled, software need not control clocks anymore
and leave clocks enabled always on.
Signed-off-by: Shardar Shariff Md <smohammed@...dia.com>
Signed-off-by: Laxman Dewangan <ldewangan@...dia.com>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@...dia.com>
---
drivers/i2c/busses/i2c-tegra.c | 32 ++++++++++++++++++++++++++++----
1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 2f654ed..8ab968e 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -235,6 +235,7 @@ struct tegra_i2c_hw_feature {
u32 setup_hold_time_fast_fast_plus_mode;
u32 setup_hold_time_hs_mode;
bool has_interface_timing_reg;
+ bool has_slcg_support;
};
/**
@@ -299,6 +300,7 @@ struct tegra_i2c_dev {
struct completion dma_complete;
bool is_curr_atomic_xfer;
int clk_divisor_hs_mode;
+ bool is_clkon_always;
};
static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
@@ -1478,6 +1480,7 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
.supports_bus_clear = false,
.has_reg_write_buffering = true,
.has_hs_mode_support = false,
+ .has_slcg_support = false,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
@@ -1506,6 +1509,7 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
.supports_bus_clear = false,
.has_reg_write_buffering = true,
.has_hs_mode_support = false,
+ .has_slcg_support = false,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
@@ -1534,6 +1538,7 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
.supports_bus_clear = true,
.has_reg_write_buffering = true,
.has_hs_mode_support = false,
+ .has_slcg_support = false,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
@@ -1562,6 +1567,7 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
.supports_bus_clear = true,
.has_reg_write_buffering = true,
.has_hs_mode_support = false,
+ .has_slcg_support = false,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
@@ -1590,6 +1596,7 @@ static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
.supports_bus_clear = true,
.has_reg_write_buffering = true,
.has_hs_mode_support = false,
+ .has_slcg_support = false,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
@@ -1618,6 +1625,7 @@ static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
.supports_bus_clear = true,
.has_reg_write_buffering = false,
.has_hs_mode_support = false,
+ .has_slcg_support = true,
.has_apb_dma = false,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x3,
@@ -1646,6 +1654,7 @@ static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
.supports_bus_clear = true,
.has_reg_write_buffering = false,
.has_hs_mode_support = true,
+ .has_slcg_support = true,
.has_apb_dma = false,
.tlow_std_mode = 0x8,
.thigh_std_mode = 0x7,
@@ -1822,7 +1831,12 @@ static int tegra_i2c_probe(struct platform_device *pdev)
}
}
- if (i2c_dev->is_multimaster_mode) {
+ if (i2c_dev->is_multimaster_mode || i2c_dev->hw->has_slcg_support)
+ i2c_dev->is_clkon_always = true;
+ else
+ i2c_dev->is_clkon_always = false;
+
+ if (i2c_dev->is_clkon_always) {
ret = clk_enable(i2c_dev->div_clk);
if (ret < 0) {
dev_err(i2c_dev->dev, "div_clk enable failed %d\n",
@@ -1875,7 +1889,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
tegra_i2c_release_dma(i2c_dev);
disable_div_clk:
- if (i2c_dev->is_multimaster_mode)
+ if (i2c_dev->is_clkon_always)
clk_disable(i2c_dev->div_clk);
put_rpm:
@@ -1908,7 +1922,7 @@ static int tegra_i2c_remove(struct platform_device *pdev)
i2c_del_adapter(&i2c_dev->adapter);
- if (i2c_dev->is_multimaster_mode)
+ if (i2c_dev->is_clkon_always)
clk_disable(i2c_dev->div_clk);
pm_runtime_disable(&pdev->dev);
@@ -1932,7 +1946,8 @@ static int __maybe_unused tegra_i2c_suspend(struct device *dev)
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int err = 0;
- i2c_mark_adapter_suspended(&i2c_dev->adapter);
+ if (i2c_dev->is_clkon_always)
+ clk_disable(i2c_dev->div_clk);
if (!pm_runtime_status_suspended(dev))
err = tegra_i2c_runtime_suspend(dev);
@@ -1968,6 +1983,15 @@ static int __maybe_unused tegra_i2c_resume(struct device *dev)
return err;
}
+ if (i2c_dev->is_clkon_always) {
+ err = clk_enable(i2c_dev->div_clk);
+ if (err < 0) {
+ dev_err(i2c_dev->dev, "clock enable failed %d\n",
+ err);
+ return err;
+ }
+ }
+
i2c_mark_adapter_resumed(&i2c_dev->adapter);
return 0;
--
2.7.4
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