From ebcc5a0d08e6a680558ed74f5dd724427ff5a29b Mon Sep 17 00:00:00 2001 From: "Mark A. Greer" Date: Tue, 25 Mar 2014 08:54:36 -0700 Subject: [PATCH] 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 Signed-off-by: Samuel Ortiz --- drivers/nfc/trf7970a.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c index 352aaab807b6..203d86fb1d54 100644 --- a/drivers/nfc/trf7970a.c +++ b/drivers/nfc/trf7970a.c @@ -336,6 +336,7 @@ struct trf7970a { 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 @@ static int trf7970a_init(struct trf7970a *trf) 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 @@ static int trf7970a_probe(struct spi_device *spi) 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 @@ static int trf7970a_probe(struct spi_device *spi) 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, -- 2.30.2