diff options
| author | Geoff Lansberry <geoff@kuvee.com> | 2016-12-22 07:18:33 +0300 |
|---|---|---|
| committer | Samuel Ortiz <sameo@linux.intel.com> | 2017-04-05 12:04:03 +0300 |
| commit | 49d22c70aaf07cd7e33346b247f5df3ddb072ee0 (patch) | |
| tree | bcdc825cff97cf30ffed42b619274e241d5e25f8 /drivers/nfc/trf7970a.c | |
| parent | 837eb4d21ecde7bde7a1fe523594fdf509055f3f (diff) | |
| download | linux-49d22c70aaf07cd7e33346b247f5df3ddb072ee0.tar.xz | |
NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage
The TRF7970A has configuration options for supporting hardware designs
with 1.8 Volt or 3.3 Volt IO. This commit adds a device tree option,
using a fixed regulator binding, for setting the io voltage to match
the hardware configuration. If no option is supplied it defaults to
3.3 volt configuration.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Geoff Lansberry <geoff@kuvee.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/nfc/trf7970a.c')
| -rw-r--r-- | drivers/nfc/trf7970a.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c index ecb786283ffa..2d1c8ca6e679 100644 --- a/drivers/nfc/trf7970a.c +++ b/drivers/nfc/trf7970a.c @@ -444,6 +444,7 @@ struct trf7970a { u8 iso_ctrl_tech; u8 modulator_sys_clk_ctrl; u8 special_fcn_reg1; + u8 io_ctrl; unsigned int guard_time; int technology; int framing; @@ -1051,6 +1052,11 @@ static int trf7970a_init(struct trf7970a *trf) if (ret) goto err_out; + ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL, + trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1)); + if (ret) + goto err_out; + ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0); if (ret) goto err_out; @@ -1767,7 +1773,7 @@ static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout, goto out_err; ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL, - TRF7970A_REG_IO_CTRL_VRS(0x1)); + trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1)); if (ret) goto out_err; @@ -2107,6 +2113,24 @@ static int trf7970a_probe(struct spi_device *spi) if (uvolts > 4000000) trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3; + trf->regulator = devm_regulator_get(&spi->dev, "vdd-io"); + if (IS_ERR(trf->regulator)) { + ret = PTR_ERR(trf->regulator); + dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret); + goto err_destroy_lock; + } + + ret = regulator_enable(trf->regulator); + if (ret) { + dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret); + goto err_destroy_lock; + } + + if (regulator_get_voltage(trf->regulator) == 1800000) { + trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW; + dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n"); + } + trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops, TRF7970A_SUPPORTED_PROTOCOLS, NFC_DIGITAL_DRV_CAPS_IN_CRC | |