diff options
| author | Duncan Laurie <dlaurie@chromium.org> | 2015-11-23 14:28:11 -0800 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2015-11-24 11:02:49 -0800 |
| commit | 3df2228c147728b516e85f8d010b0905be182045 (patch) | |
| tree | 6e40715b1f46ab195d139ccfa93c492cfe06050e /driver | |
| parent | 1ea9dece80cd020a0cea2adc63daea086aba43b8 (diff) | |
| download | chrome-ec-3df2228c147728b516e85f8d010b0905be182045.tar.gz | |
ps8740: Add a function to tune USB EQ settings
This adds a new function that can be use to apply USB EQ settings
to the mux. It currently only exposes the Tx and Rx channel
loss compensation.
BUG=chrome-os-partner:47074
BRANCH=none
TEST=build and boot on chell
Change-Id: I1ec83cdcbb17da8e7289e6633509b64f01b14348
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/313747
Reviewed-by: Shawn N <shawnn@chromium.org>
Diffstat (limited to 'driver')
| -rw-r--r-- | driver/ps8740.h | 32 | ||||
| -rw-r--r-- | driver/usb_mux_ps8740.c | 11 |
2 files changed, 43 insertions, 0 deletions
diff --git a/driver/ps8740.h b/driver/ps8740.h index ec27a7bf50..94076e7921 100644 --- a/driver/ps8740.h +++ b/driver/ps8740.h @@ -32,4 +32,36 @@ #define PS8740_REG_CHIP_ID2 0xf3 #define PS8740_CHIP_ID2 0x87 +/* USB equalization settings for Host to Mux */ +#define PS8740_REG_USB_EQ_TX 0x32 +#define PS8740_USB_EQ_TX_10_1_DB 0x00 +#define PS8740_USB_EQ_TX_14_3_DB 0x20 +#define PS8740_USB_EQ_TX_8_5_DB 0x40 +#define PS8740_USB_EQ_TX_6_5_DB 0x60 +#define PS8740_USB_EQ_TX_11_5_DB 0x80 +#define PS8740_USB_EQ_TX_9_5_DB 0xc0 +#define PS8740_USB_EQ_TX_7_5_DB 0xe0 +#define PS8740_USB_EQ_TERM_100_OHM (0 << 2) +#define PS8740_USB_EQ_TERM_85_OHM (1 << 2) + +/* USB equalization settings for Connector to Mux */ +#define PS8740_REG_USB_EQ_RX 0x3b +#define PS8740_USB_EQ_RX_4_4_DB 0x00 +#define PS8740_USB_EQ_RX_7_0_DB 0x10 +#define PS8740_USB_EQ_RX_8_2_DB 0x20 +#define PS8740_USB_EQ_RX_9_4_DB 0x30 +#define PS8740_USB_EQ_RX_10_2_DB 0x40 +#define PS8740_USB_EQ_RX_11_4_DB 0x50 +#define PS8740_USB_EQ_RX_14_3_DB 0x60 +#define PS8740_USB_EQ_RX_14_8_DB 0x70 +#define PS8740_USB_EQ_RX_15_2_DB 0x80 +#define PS8740_USB_EQ_RX_15_5_DB 0x90 +#define PS8740_USB_EQ_RX_16_2_DB 0xa0 +#define PS8740_USB_EQ_RX_17_3_DB 0xb0 +#define PS8740_USB_EQ_RX_18_4_DB 0xc0 +#define PS8740_USB_EQ_RX_20_1_DB 0xd0 +#define PS8740_USB_EQ_RX_21_3_DB 0xe0 + +int ps8740_tune_usb_eq(int i2c_addr, uint8_t tx, uint8_t rx); + #endif /* __CROS_EC_PS8740_H */ diff --git a/driver/usb_mux_ps8740.c b/driver/usb_mux_ps8740.c index dfe111bf31..dada5368f6 100644 --- a/driver/usb_mux_ps8740.c +++ b/driver/usb_mux_ps8740.c @@ -107,6 +107,17 @@ static int ps8740_get_mux(int i2c_addr, mux_state_t *mux_state) return EC_SUCCESS; } +/* Tune USB Tx/Rx Equalization */ +int ps8740_tune_usb_eq(int i2c_addr, uint8_t tx, uint8_t rx) +{ + int ret = 0; + + ret |= ps8740_write(i2c_addr, PS8740_REG_USB_EQ_TX, tx); + ret |= ps8740_write(i2c_addr, PS8740_REG_USB_EQ_RX, rx); + + return ret; +} + const struct usb_mux_driver ps8740_usb_mux_driver = { .init = ps8740_init, .set = ps8740_set_mux, |