Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934965AbcLTQQu (ORCPT ); Tue, 20 Dec 2016 11:16:50 -0500 Received: from mail-qk0-f182.google.com ([209.85.220.182]:34715 "EHLO mail-qk0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755450AbcLTQQo (ORCPT ); Tue, 20 Dec 2016 11:16:44 -0500 From: Geoff Lansberry X-Google-Original-From: Geoff Lansberry To: linux-wireless@vger.kernel.org Cc: lauro.venancio@openbossa.org, aloisio.almeida@openbossa.org, sameo@linux.intel.com, robh+dt@kernel.org, mark.rutland@arm.com, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, mgreer@animalcreek.com, justin@kuvee.com, Geoff Lansberry Subject: [PATCH 2/3] NFC: trf7970a: Add device tree option of 1.8 Volt IO voltage Date: Tue, 20 Dec 2016 11:16:31 -0500 Message-Id: <1482250592-4268-2-git-send-email-glansberry@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1482250592-4268-1-git-send-email-glansberry@gmail.com> References: <1482250592-4268-1-git-send-email-glansberry@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3742 Lines: 109 From: Geoff Lansberry 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 4e051e9..8a88195 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