From: Geoff Lansberry <geoff@xxxxxxxxx> 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. --- .../devicetree/bindings/net/nfc/trf7970a.txt | 4 ++-- drivers/nfc/trf7970a.c | 28 +++++++++++++++++++++- 2 files changed, 29 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt index e262ac1..b5777d8 100644 --- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt +++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt @@ -21,9 +21,9 @@ Optional SoC Specific Properties: - t5t-rmb-extra-byte-quirk: Specify that the trf7970a has the erratum where an extra byte is returned by Read Multiple Block commands issued to Type 5 tags. +- vdd-io-supply: Regulator specifying voltage for vdd-io - clock-frequency: Set to specify that the input frequency to the trf7970a is 13560000Hz or 27120000Hz - Example (for ARM-based BeagleBone with TRF7970A on SPI1): &spi1 { @@ -41,11 +41,11 @@ Example (for ARM-based BeagleBone with TRF7970A on SPI1): <&gpio2 5 GPIO_ACTIVE_LOW>; vin-supply = <&ldo3_reg>; vin-voltage-override = <5000000>; + vdd-io-supply = <&ldo2_reg>; autosuspend-delay = <30000>; irq-status-read-quirk; en2-rf-quirk; t5t-rmb-extra-byte-quirk; - vdd_io_1v8; clock-frequency = <27120000>; status = "okay"; }; diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c index c9cb278..94c31f8 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; @@ -2062,6 +2068,7 @@ static int trf7970a_probe(struct spi_device *spi) return ret; } + of_property_read_u32(np, "clock-frequency", &clk_freq); if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) || (clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY)) { @@ -2105,6 +2112,25 @@ 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 | -- Signed-off-by: Geoff Lansberry <geoff@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html