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i2c: designware: Add support for AMD I2C controller

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Add support for AMD version of the DW I2C host controller. The device is
enumerated from ACPI namespace with ACPI ID AMD0010. Because the core
driver needs an input source clock, and this is not an Intel LPSS device
where clocks are provided through drivers/acpi/acpi_lpss.c, we register the
clock ourselves if the clock rate is given in ->driver_data

Signed-off-by: Carl Peng <carlpeng008@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Carl Peng 2014-09-30 13:04:55 +03:00 committed by Wolfram Sang
parent 925ddb240d
commit a445900c90
2 changed files with 28 additions and 0 deletions
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1
drivers/i2c/busses/Kconfig
View File

@ -434,6 +434,7 @@ config I2C_DESIGNWARE_CORE
config I2C_DESIGNWARE_PLATFORM
tristate "Synopsys DesignWare Platform"
select I2C_DESIGNWARE_CORE
depends on (ACPI && COMMON_CLK) || !ACPI
help
If you say yes to this option, support will be included for the
Synopsys DesignWare I2C adapter. Only master mode is supported.

27
drivers/i2c/busses/i2c-designware-platdrv.c
View File

@ -30,6 +30,7 @@
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/err.h>
@ -80,6 +81,7 @@ static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
static int dw_i2c_acpi_configure(struct platform_device *pdev)
{
struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
const struct acpi_device_id *id;
dev->adapter.nr = -1;
dev->tx_fifo_depth = 32;
@ -93,9 +95,29 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev)
dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
&dev->sda_hold_time);
/*
* Provide a way for Designware I2C host controllers that are not
* based on Intel LPSS to specify their input clock frequency via
* id->driver_data.
*/
id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
if (id && id->driver_data)
clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
CLK_IS_ROOT, id->driver_data);
return 0;
}
static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
{
struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
const struct acpi_device_id *id;
id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
if (id && id->driver_data)
clk_unregister(dev->clk);
}
static const struct acpi_device_id dw_i2c_acpi_match[] = {
{ "INT33C2", 0 },
{ "INT33C3", 0 },
@ -103,6 +125,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = {
{ "INT3433", 0 },
{ "80860F41", 0 },
{ "808622C1", 0 },
{ "AMD0010", 133 * 1000 * 1000 },
{ }
};
MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
@ -111,6 +134,7 @@ static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
{
return -ENODEV;
}
static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
#endif
static int dw_i2c_probe(struct platform_device *pdev)
@ -258,6 +282,9 @@ static int dw_i2c_remove(struct platform_device *pdev)
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
if (ACPI_COMPANION(&pdev->dev))
dw_i2c_acpi_unconfigure(pdev);
return 0;
}