NFC: trf7970a: Set correct Vin voltage in Chip Status Control register
Currently, the trf7970a driver assumes that the Vin voltage is 5V when
it writes to the 'Chip Status Control' register. That may not be correct
so use the regulator facility to get the Vin voltage and set the VRS5_3
bit correctly when writing to that register.
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 352aaab..203d86f 100644
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -336,6 +336,7 @@
struct sk_buff *rx_skb;
nfc_digital_cmd_complete_t cb;
void *cb_arg;
+ u8 chip_status_ctrl;
u8 iso_ctrl;
u8 iso_ctrl_tech;
u8 modulator_sys_clk_ctrl;
@@ -779,8 +780,7 @@
trf->special_fcn_reg1 = 0;
ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
- TRF7970A_CHIP_STATUS_RF_ON |
- TRF7970A_CHIP_STATUS_VRS5_3);
+ trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_RF_ON);
if (ret)
goto err_out;
@@ -1245,7 +1245,7 @@
struct device_node *np = spi->dev.of_node;
const struct spi_device_id *id = spi_get_device_id(spi);
struct trf7970a *trf;
- int ret;
+ int uvolts, ret;
if (!np) {
dev_err(&spi->dev, "No Device Tree entry\n");
@@ -1315,6 +1315,11 @@
goto err_destroy_lock;
}
+ uvolts = regulator_get_voltage(trf->regulator);
+
+ if (uvolts > 4000000)
+ trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
+
trf->powering_up = true;
trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,