summaryrefslogtreecommitdiffstats
path: root/drivers/i2c
diff options
context:
space:
mode:
authorCarl Peng <carlpeng008@gmail.com>2014-09-30 13:04:55 +0300
committerWolfram Sang <wsa@the-dreams.de>2014-10-06 19:50:21 +0200
commita445900c906092f3b49ee40a7365d0d54acc568e (patch)
tree93e68e3b3826d394d13f82ba89e52343f359a42c /drivers/i2c
parent925ddb240d6c76e56dd3aa22493f5755c452ba61 (diff)
i2c: designware: Add support for AMD I2C controller
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>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/Kconfig1
-rw-r--r--drivers/i2c/busses/i2c-designware-platdrv.c27
2 files changed, 28 insertions, 0 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index e1d491b0b9c..242f491cf58 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -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.
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index e59c63ae4d4..a7431150acf 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -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;
}