Return-path: Received: from mail-qt0-f182.google.com ([209.85.216.182]:33776 "EHLO mail-qt0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762936AbcLTQLJ (ORCPT ); Tue, 20 Dec 2016 11:11:09 -0500 Received: by mail-qt0-f182.google.com with SMTP id p16so178623880qta.0 for ; Tue, 20 Dec 2016 08:11:08 -0800 (PST) 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 1/3] NFC: trf7970a: add device tree option for 27MHz clock Date: Tue, 20 Dec 2016 11:10:44 -0500 Message-Id: <1482250250-4192-1-git-send-email-glansberry@gmail.com> (sfid-20161220_171504_185951_23169061) Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Geoff Lansberry The TRF7970A has configuration options to support hardware designs which use a 27.12MHz clock. This commit adds a device tree option 'clock-frequency' to support configuring the this chip for default 13.56MHz clock or the optional 27.12MHz clock. --- .../devicetree/bindings/net/nfc/trf7970a.txt | 4 ++ drivers/nfc/trf7970a.c | 50 +++++++++++++++++----- 2 files changed, 43 insertions(+), 11 deletions(-) diff --git a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt index 32b35a0..e262ac1 100644 --- a/Documentation/devicetree/bindings/net/nfc/trf7970a.txt +++ b/Documentation/devicetree/bindings/net/nfc/trf7970a.txt @@ -21,6 +21,8 @@ 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. +- 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): @@ -43,6 +45,8 @@ Example (for ARM-based BeagleBone with TRF7970A on SPI1): 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 26c9dbb..4e051e9 100644 --- a/drivers/nfc/trf7970a.c +++ b/drivers/nfc/trf7970a.c @@ -124,6 +124,9 @@ NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK) #define TRF7970A_AUTOSUSPEND_DELAY 30000 /* 30 seconds */ +#define TRF7970A_13MHZ_CLOCK_FREQUENCY 13560000 +#define TRF7970A_27MHZ_CLOCK_FREQUENCY 27120000 + #define TRF7970A_RX_SKB_ALLOC_SIZE 256 @@ -1056,12 +1059,11 @@ static int trf7970a_init(struct trf7970a *trf) trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON; - ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, 0); + ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, + trf->modulator_sys_clk_ctrl); if (ret) goto err_out; - trf->modulator_sys_clk_ctrl = 0; - ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 | TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32); @@ -1181,27 +1183,37 @@ static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech) switch (tech) { case NFC_DIGITAL_RF_TECH_106A: trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_OOK; trf->guard_time = TRF7970A_GUARD_TIME_NFCA; break; case NFC_DIGITAL_RF_TECH_106B: trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_ASK10; trf->guard_time = TRF7970A_GUARD_TIME_NFCB; break; case NFC_DIGITAL_RF_TECH_212F: trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_ASK10; trf->guard_time = TRF7970A_GUARD_TIME_NFCF; break; case NFC_DIGITAL_RF_TECH_424F: trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_ASK10; trf->guard_time = TRF7970A_GUARD_TIME_NFCF; break; case NFC_DIGITAL_RF_TECH_ISO15693: trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_OOK; trf->guard_time = TRF7970A_GUARD_TIME_15693; break; default: @@ -1571,17 +1583,23 @@ static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech) trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE | TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_OOK; break; case NFC_DIGITAL_RF_TECH_212F: trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE | TRF7970A_ISO_CTRL_NFC_NFCF_212; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_ASK10; break; case NFC_DIGITAL_RF_TECH_424F: trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE | TRF7970A_ISO_CTRL_NFC_NFCF_424; - trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xF8) | + TRF7970A_MODULATOR_DEPTH_ASK10; break; default: dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech); @@ -1987,6 +2005,7 @@ static int trf7970a_probe(struct spi_device *spi) struct device_node *np = spi->dev.of_node; struct trf7970a *trf; int uvolts, autosuspend_delay, ret; + u32 clk_freq = 13560000; if (!np) { dev_err(&spi->dev, "No Device Tree entry\n"); @@ -2043,6 +2062,15 @@ 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)) { + dev_err(trf->dev, + "clock-frequency (%u Hz) unsupported\n", + clk_freq); + return -EINVAL; + } + if (of_property_read_bool(np, "en2-rf-quirk")) trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW; -- Signed-off-by: Geoff Lansberry