From: Xiang Wang <[email protected]> 1. Add High-speed mode support in designware core 2. Add function i2c_dw_acpi_setup_speed to determine the bus speed from ACPI table.
Signed-off-by: Xiang Wang <[email protected]> --- drivers/i2c/busses/i2c-designware-core.c | 88 ++++++++++++++++++++++++++++++++ drivers/i2c/busses/i2c-designware-core.h | 11 ++++ 2 files changed, 99 insertions(+) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 6f19a33..f5c0d18 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -30,6 +30,7 @@ #include <linux/pm_runtime.h> #include <linux/delay.h> #include <linux/module.h> +#include <linux/acpi.h> #include "i2c-designware-core.h" /* @@ -42,6 +43,8 @@ #define DW_IC_SS_SCL_LCNT 0x18 #define DW_IC_FS_SCL_HCNT 0x1c #define DW_IC_FS_SCL_LCNT 0x20 +#define DW_IC_HS_SCL_HCNT 0x24 +#define DW_IC_HS_SCL_LCNT 0x28 #define DW_IC_INTR_STAT 0x2c #define DW_IC_INTR_MASK 0x30 #define DW_IC_RAW_INTR_STAT 0x34 @@ -358,6 +361,16 @@ int i2c_dw_init(struct dw_i2c_dev *dev) dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); + if (dev->hs_hcnt && dev->hs_lcnt) { + hcnt = dev->hs_hcnt; + lcnt = dev->hs_lcnt; + + dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT); + dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT); + dev_dbg(dev->dev, "High-speed mode HCNT:LCNT = %d:%d\n", + hcnt, lcnt); + } + /* Configure SDA Hold Time if required */ if (dev->sda_hold_time) { reg = dw_readl(dev, DW_IC_COMP_VERSION); @@ -381,6 +394,81 @@ int i2c_dw_init(struct dw_i2c_dev *dev) } EXPORT_SYMBOL_GPL(i2c_dw_init); +#ifdef CONFIG_ACPI +static int i2c_dw_acpi_get_freq(struct acpi_resource *ares, void *data) +{ + struct dw_i2c_dev *i2c = data; + struct acpi_resource_i2c_serialbus *sb; + u32 i2c_speed; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + sb = &ares->data.i2c_serial_bus; + + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) { + i2c_speed = sb->connection_speed; + if (i2c_speed == DW_STD_SPEED) { + i2c->master_cfg &= ~DW_IC_SPEED_MASK; + i2c->master_cfg |= DW_IC_CON_SPEED_STD; + } else if (i2c_speed == DW_FAST_SPEED) { + i2c->master_cfg &= ~DW_IC_SPEED_MASK; + i2c->master_cfg |= DW_IC_CON_SPEED_FAST; + } else if (i2c_speed == DW_HIGH_SPEED) { + i2c->master_cfg &= ~DW_IC_SPEED_MASK; + i2c->master_cfg |= DW_IC_CON_SPEED_HIGH; + } else { + dev_err(i2c->dev, "unsupported speed: %d\n", + i2c_speed); + } + + dev_dbg(i2c->dev, "i2c device speed from acpi = %d\n", + i2c_speed); + } + } + + return 1; +} + +static acpi_status acpi_i2c_find_device_speed(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct dw_i2c_dev *i2c = data; + struct list_head resource_list; + struct acpi_device *adev; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + if (acpi_bus_get_status(adev) || !adev->status.present) + return AE_OK; + + INIT_LIST_HEAD(&resource_list); + acpi_dev_get_resources(adev, &resource_list, + i2c_dw_acpi_get_freq, i2c); + acpi_dev_free_resource_list(&resource_list); + + return AE_OK; +} + +void i2c_dw_acpi_setup_speed(struct device *pdev, struct dw_i2c_dev *dev) +{ + acpi_handle handle = ACPI_HANDLE(pdev); + acpi_status status; + + if (handle == NULL) + return; + + /* Find I2C adapter bus frequency */ + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_i2c_find_device_speed, NULL, + dev, NULL); + if (ACPI_FAILURE(status)) + dev_warn(pdev, "failed to get I2C bus freq\n"); +} + +#else +void i2c_dw_acpi_setup_speed(struct device *pdev, struct dw_i2c_dev *dev) {} +#endif +EXPORT_SYMBOL_GPL(i2c_dw_acpi_setup_speed); + /* * Waiting for bus not busy */ diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 9630222..16f53d8 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -24,12 +24,17 @@ #define DW_IC_CON_MASTER 0x1 +#define DW_IC_SPEED_MASK 0x6 #define DW_IC_CON_SPEED_STD 0x2 #define DW_IC_CON_SPEED_FAST 0x4 +#define DW_IC_CON_SPEED_HIGH 0x6 #define DW_IC_CON_10BITADDR_MASTER 0x10 #define DW_IC_CON_RESTART_EN 0x20 #define DW_IC_CON_SLAVE_DISABLE 0x40 +#define DW_STD_SPEED 100000 +#define DW_FAST_SPEED 400000 +#define DW_HIGH_SPEED 3400000 /** * struct dw_i2c_dev - private i2c-designware data @@ -61,6 +66,8 @@ * @ss_lcnt: standard speed LCNT value * @fs_hcnt: fast speed HCNT value * @fs_lcnt: fast speed LCNT value + * @hs_hcnt: high speed HCNT value + * @hs_lcnt: high speed LCNT value * @acquire_lock: function to acquire a hardware lock on the bus * @release_lock: function to release a hardware lock on the bus * @pm_runtime_disabled: true if pm runtime is disabled @@ -104,6 +111,8 @@ struct dw_i2c_dev { u16 ss_lcnt; u16 fs_hcnt; u16 fs_lcnt; + u16 hs_hcnt; + u16 hs_lcnt; int (*acquire_lock)(struct dw_i2c_dev *dev); void (*release_lock)(struct dw_i2c_dev *dev); bool pm_runtime_disabled; @@ -114,6 +123,8 @@ struct dw_i2c_dev { extern u32 dw_readl(struct dw_i2c_dev *dev, int offset); extern void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset); +extern void i2c_dw_acpi_setup_speed(struct device *pdev, + struct dw_i2c_dev *dev); extern int i2c_dw_init(struct dw_i2c_dev *dev); extern int i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num); -- 2.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
