[PATCH v2 2/3] i2c: designware: Rework probe() to get clock a bit later

From: Mika Westerberg
Date: Tue Sep 30 2014 - 06:05:06 EST


In order to be able to create missing clock for AMD (and in future possibly
others) we move getting clock for the device a bit later. Also make ACPI/DT
configuration in the same place depending on from where the device was
enumerated from.

Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-platdrv.c | 38 ++++++++++++++---------------
1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 353adc4dc583..e59c63ae4d41 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -81,9 +81,6 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev)
{
struct dw_i2c_dev *dev = platform_get_drvdata(pdev);

- if (!ACPI_HANDLE(&pdev->dev))
- return -ENODEV;
-
dev->adapter.nr = -1;
dev->tx_fifo_depth = 32;
dev->rx_fifo_depth = 32;
@@ -123,7 +120,7 @@ static int dw_i2c_probe(struct platform_device *pdev)
struct resource *mem;
struct dw_i2c_platform_data *pdata;
int irq, r;
- u32 clk_freq;
+ u32 clk_freq, ht = 0;

irq = platform_get_irq(pdev, 0);
if (irq < 0) {
@@ -146,24 +143,14 @@ static int dw_i2c_probe(struct platform_device *pdev)
dev->irq = irq;
platform_set_drvdata(pdev, dev);

- 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);
-
/* fast mode by default because of legacy reasons */
clk_freq = 400000;

- if (pdev->dev.of_node) {
- u32 ht = 0;
- u32 ic_clk = dev->get_clk_rate_khz(dev);
-
+ if (ACPI_COMPANION(&pdev->dev)) {
+ dw_i2c_acpi_configure(pdev);
+ } else if (pdev->dev.of_node) {
of_property_read_u32(pdev->dev.of_node,
"i2c-sda-hold-time-ns", &ht);
- dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
- 1000000);

of_property_read_u32(pdev->dev.of_node,
"i2c-sda-falling-time-ns",
@@ -202,9 +189,20 @@ static int dw_i2c_probe(struct platform_device *pdev)
dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;

- /* Try first if we can configure the device from ACPI */
- r = dw_i2c_acpi_configure(pdev);
- if (r) {
+ 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 (!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->tx_fifo_depth) {
u32 param1 = i2c_dw_read_comp_param(dev);

dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
--
2.1.0

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