[PATCH v3 1/1] phy: tusb1210: use bitmasks to set VENDOR_SPECIFIC2

From: Liam Beguin
Date: Mon Aug 17 2020 - 13:35:20 EST


From: Liam Beguin <lvb@xxxxxxxxxx>

Start by reading the content of the VENDOR_SPECIFIC2 register and update
each bit field based on device properties when defined.

The use of bit masks prevents fields from overriding each other and
enables users to clear bits which are set by default, like datapolarity
in this instance.

Signed-off-by: Liam Beguin <lvb@xxxxxxxxxx>
---
Changes since v1:
- use set_mask_bits

Changes since v2:
- fix missing bit shift dropped in v2
- rebase on 5.9-rc1

drivers/phy/ti/phy-tusb1210.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/phy/ti/phy-tusb1210.c b/drivers/phy/ti/phy-tusb1210.c
index d8d0cc11d187..358842b5790f 100644
--- a/drivers/phy/ti/phy-tusb1210.c
+++ b/drivers/phy/ti/phy-tusb1210.c
@@ -14,8 +14,11 @@

#define TUSB1210_VENDOR_SPECIFIC2 0x80
#define TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT 0
+#define TUSB1210_VENDOR_SPECIFIC2_IHSTX_MASK GENMASK(3, 0)
#define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT 4
+#define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_MASK GENMASK(5, 4)
#define TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT 6
+#define TUSB1210_VENDOR_SPECIFIC2_DP_MASK BIT(6)

struct tusb1210 {
struct ulpi *ulpi;
@@ -118,23 +121,27 @@ static int tusb1210_probe(struct ulpi *ulpi)
* diagram optimization and DP/DM swap.
*/

+ reg = ulpi_read(ulpi, TUSB1210_VENDOR_SPECIFIC2);
+
/* High speed output drive strength configuration */
- device_property_read_u8(&ulpi->dev, "ihstx", &val);
- reg = val << TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT;
+ if (!device_property_read_u8(&ulpi->dev, "ihstx", &val))
+ reg = set_mask_bits(&reg, TUSB1210_VENDOR_SPECIFIC2_IHSTX_MASK,
+ val << TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT);

/* High speed output impedance configuration */
- device_property_read_u8(&ulpi->dev, "zhsdrv", &val);
- reg |= val << TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT;
+ if (!device_property_read_u8(&ulpi->dev, "zhsdrv", &val))
+ reg = set_mask_bits(&reg, TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_MASK,
+ val << TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT);

/* DP/DM swap control */
- device_property_read_u8(&ulpi->dev, "datapolarity", &val);
- reg |= val << TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT;
-
- if (reg) {
- ulpi_write(ulpi, TUSB1210_VENDOR_SPECIFIC2, reg);
- tusb->vendor_specific2 = reg;
+ if (!device_property_read_u8(&ulpi->dev, "datapolarity", &val)) {
+ reg = set_mask_bits(&reg, TUSB1210_VENDOR_SPECIFIC2_DP_MASK,
+ val << TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT);
}

+ ulpi_write(ulpi, TUSB1210_VENDOR_SPECIFIC2, reg);
+ tusb->vendor_specific2 = reg;
+
tusb->phy = ulpi_phy_create(ulpi, &phy_ops);
if (IS_ERR(tusb->phy))
return PTR_ERR(tusb->phy);

base-commit: 9123e3a74ec7b934a4a099e98af6a61c2f80bbf5
--
2.27.0