Return-path: Received: from mail-lf0-f50.google.com ([209.85.215.50]:35283 "EHLO mail-lf0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754135AbcLTR7I (ORCPT ); Tue, 20 Dec 2016 12:59:08 -0500 Received: by mail-lf0-f50.google.com with SMTP id b14so81388726lfg.2 for ; Tue, 20 Dec 2016 09:59:07 -0800 (PST) Subject: Re: [PATCH 1/3] NFC: trf7970a: add device tree option for 27MHz clock To: Geoff Lansberry , linux-wireless@vger.kernel.org References: <1482250592-4268-1-git-send-email-glansberry@gmail.com> 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 From: Jones Desougi Message-ID: (sfid-20161220_185913_366504_F65668F9) Date: Tue, 20 Dec 2016 18:58:58 +0100 MIME-Version: 1.0 In-Reply-To: <1482250592-4268-1-git-send-email-glansberry@gmail.com> Content-Type: text/plain; charset=windows-1252 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2016-12-20 17:16, Geoff Lansberry wrote: > 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 > + You're adding an empty line here that is removed in the next patch. > > 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; This does not belong here, and so no need to remove in the next patch. > + 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; Use TRF7970A_13MHZ_CLOCK_FREQUENCY here? > > 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)) { Two comparisons with 27MHz, missing 13MHz. > + 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; > >