From: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
The current driver uses input clock source frequency to calculate
values for [SS|FS]_[HC|LC] registers. However, when booting ACPI, we do not
currently have a good way to provide the frequency information.
Instead, we can leverage the SSCN and FFCN ACPI methods, which can be used
to directly provide these values. So, the clock information should
no longer be required during probing.
However, since clk can be invalid, additional checks must be done where
we are making use of it.
Signed-off-by: Mika Westerberg <mika.westerb...@linux.intel.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
Tested-by: Loc Ho <l...@apm.com>
Signed-off-by: Wolfram Sang <w...@the-dreams.de>
(cherry picked from commit b33af11de236fd6e25f3716182f008039ec68e93)
Signed-off-by: Voon, Weifeng <weifeng.v...@intel.com>
---
drivers/i2c/busses/i2c-designware-core.c | 22 +++++++++++++-------
drivers/i2c/busses/i2c-designware-platdrv.c | 31 +++++++++++++++++++----------
2 files changed, 35 insertions(+), 18 deletions(-)
diff --git a/drivers/i2c/busses/i2c-designware-core.c
b/drivers/i2c/busses/i2c-designware-core.c
index f7b34b3..ba9732c 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -271,6 +271,17 @@ static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool
enable)
enable ? "en" : "dis");
}
+static unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
+{
+ /*
+ * Clock is not necessary if we got LCNT/HCNT values directly from
+ * the platform code.
+ */
+ if (WARN_ON_ONCE(!dev->get_clk_rate_khz))
+ return 0;
+ return dev->get_clk_rate_khz(dev);
+}
+
/**
* i2c_dw_init() - initialize the designware i2c master hardware
* @dev: device private data
@@ -281,7 +292,6 @@ static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool
enable)
*/
int i2c_dw_init(struct dw_i2c_dev *dev)
{
- u32 input_clock_khz;
u32 hcnt, lcnt;
u32 reg;
u32 sda_falling_time, scl_falling_time;
@@ -295,8 +305,6 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
}
}
- input_clock_khz = dev->get_clk_rate_khz(dev);
-
reg = dw_readl(dev, DW_IC_COMP_TYPE);
if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
/* Configure register endianess access */
@@ -325,12 +333,12 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
hcnt = dev->ss_hcnt;
lcnt = dev->ss_lcnt;
} else {
- hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+ hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
4000, /* tHD;STA = tHIGH = 4.0 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
- lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+ lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
4700, /* tLOW = 4.7 us */
scl_falling_time,
0); /* No offset */
@@ -344,12 +352,12 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
hcnt = dev->fs_hcnt;
lcnt = dev->fs_lcnt;
} else {
- hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+ hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
600, /* tHD;STA = tHIGH = 0.6 us */
sda_falling_time,
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
- lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+ lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
1300, /* tLOW = 1.3 us */
scl_falling_time,
0); /* No offset */
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
b/drivers/i2c/busses/i2c-designware-platdrv.c
index a92f840..1c61a7a 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -134,6 +134,18 @@ static inline int dw_i2c_acpi_configure(struct
platform_device *pdev)
}
#endif
+static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
+{
+ if (IS_ERR(i_dev->clk))
+ return PTR_ERR(i_dev->clk);
+
+ if (prepare)
+ return clk_prepare_enable(i_dev->clk);
+
+ clk_disable_unprepare(i_dev->clk);
+ return 0;
+}
+
static int dw_i2c_plat_probe(struct platform_device *pdev)
{
struct dw_i2c_dev *dev;
@@ -211,16 +223,13 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
dev->clk = devm_clk_get(&pdev->dev, NULL);
- dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
- if (IS_ERR(dev->clk))
- return PTR_ERR(dev->clk);
- clk_prepare_enable(dev->clk);
+ if (!i2c_dw_plat_prepare_clk(dev, true)) {
+ dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
- if (!dev->sda_hold_time && ht) {
- u32 ic_clk = dev->get_clk_rate_khz(dev);
-
- dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
- 1000000);
+ if (!dev->sda_hold_time && ht)
+ dev->sda_hold_time = div_u64(
+ (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
+ 1000000);
}
if (!dev->tx_fifo_depth) {
@@ -301,7 +310,7 @@ static int dw_i2c_plat_suspend(struct device *dev)
struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
i2c_dw_disable(i_dev);
- clk_disable_unprepare(i_dev->clk);
+ i2c_dw_plat_prepare_clk(i_dev, false);
return 0;
}
@@ -311,7 +320,7 @@ static int dw_i2c_plat_resume(struct device *dev)
struct platform_device *pdev = to_platform_device(dev);
struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
- clk_prepare_enable(i_dev->clk);
+ i2c_dw_plat_prepare_clk(i_dev, true);
if (!i_dev->pm_runtime_disabled)
i2c_dw_init(i_dev);
--
1.9.1
--
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