From patchwork Fri Mar 5 13:38:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 12118515 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E30BC433E0 for ; Fri, 5 Mar 2021 13:39:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1EF4B64F56 for ; Fri, 5 Mar 2021 13:39:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230301AbhCENiz (ORCPT ); Fri, 5 Mar 2021 08:38:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230390AbhCENiZ (ORCPT ); Fri, 5 Mar 2021 08:38:25 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FAE9C061574 for ; Fri, 5 Mar 2021 05:38:25 -0800 (PST) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lIAen-00039n-1T; Fri, 05 Mar 2021 14:38:17 +0100 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lIAel-0007IQ-6h; Fri, 05 Mar 2021 14:38:15 +0100 From: Oleksij Rempel To: Rob Herring , Jonathan Cameron Cc: Oleksij Rempel , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Pengutronix Kernel Team , David Jander , Robin van der Gracht , linux-iio@vger.kernel.org, Lars-Peter Clausen , Peter Meerwald-Stadler , Dmitry Torokhov Subject: [PATCH v1 1/2] dt-bindings:iio:adc: add documentation for TI TSC2046 controller Date: Fri, 5 Mar 2021 14:38:12 +0100 Message-Id: <20210305133813.27967-2-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210305133813.27967-1-o.rempel@pengutronix.de> References: <20210305133813.27967-1-o.rempel@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-iio@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Add a binding documentation for the TI TSC2046 touchscreen controllers ADC functionality. Signed-off-by: Oleksij Rempel Reviewed-by: Rob Herring --- .../bindings/iio/adc/ti,tsc2046.yaml | 52 +++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/ti,tsc2046.yaml diff --git a/Documentation/devicetree/bindings/iio/adc/ti,tsc2046.yaml b/Documentation/devicetree/bindings/iio/adc/ti,tsc2046.yaml new file mode 100644 index 000000000000..cd1dd40f84df --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/ti,tsc2046.yaml @@ -0,0 +1,52 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iio/adc/ti,tsc2046.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Texas Instruments TSC2046 touch screen controller. + +maintainers: + - Oleksij Rempel + +description: | + TSC2046 is a touch screen controller with 8 channels ADC. + +properties: + compatible: + enum: + - ti,tsc2046e-adc + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + spi-max-frequency: true + + "#io-channel-cells": + const: 1 + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + #include + spi { + #address-cells = <1>; + #size-cells = <0>; + + adc@0 { + compatible = "ti,tsc2046e-adc"; + reg = <0>; + spi-max-frequency = <1000000>; + interrupts-extended = <&gpio3 20 IRQ_TYPE_LEVEL_LOW>; + #io-channel-cells = <1>; + }; + }; +... From patchwork Fri Mar 5 13:38:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 12118517 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15335C43381 for ; Fri, 5 Mar 2021 13:39:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2E7F6502E for ; Fri, 5 Mar 2021 13:39:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229729AbhCENiz (ORCPT ); Fri, 5 Mar 2021 08:38:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229719AbhCENi0 (ORCPT ); Fri, 5 Mar 2021 08:38:26 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E0A0C061574 for ; Fri, 5 Mar 2021 05:38:26 -0800 (PST) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lIAen-00039o-1T; Fri, 05 Mar 2021 14:38:17 +0100 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lIAel-0007IZ-7m; Fri, 05 Mar 2021 14:38:15 +0100 From: Oleksij Rempel To: Rob Herring , Jonathan Cameron Cc: Oleksij Rempel , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Pengutronix Kernel Team , David Jander , Robin van der Gracht , linux-iio@vger.kernel.org, Lars-Peter Clausen , Peter Meerwald-Stadler , Dmitry Torokhov Subject: [PATCH v1 2/2] iio: adc: add ADC driver for the TI TSC2046 controller Date: Fri, 5 Mar 2021 14:38:13 +0100 Message-Id: <20210305133813.27967-3-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210305133813.27967-1-o.rempel@pengutronix.de> References: <20210305133813.27967-1-o.rempel@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-iio@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Basically the TI TSC2046 touchscreen controller is 8 channel ADC optimized for the touchscreen use case. By implementing it as IIO ADC device, we can make use of resistive-adc-touch and iio-hwmon drivers. So far, this driver was tested with custom version of resistive-adc-touch driver, since it need to be extended to make use of Z1 and Z2 channels. The X/Y are working without additional changes. Signed-off-by: Oleksij Rempel --- MAINTAINERS | 8 + drivers/iio/adc/Kconfig | 12 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ti-tsc2046.c | 652 +++++++++++++++++++++++++++++++++++ 4 files changed, 673 insertions(+) create mode 100644 drivers/iio/adc/ti-tsc2046.c diff --git a/MAINTAINERS b/MAINTAINERS index 3fea1a934b32..2d33c6442a55 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17852,6 +17852,14 @@ S: Supported F: Documentation/devicetree/bindings/net/nfc/trf7970a.txt F: drivers/nfc/trf7970a.c +TI TSC2046 ADC DRIVER +M: Oleksij Rempel +R: kernel@pengutronix.de +L: linux-iio@vger.kernel.org +S: Maintained +F: Documentation/devicetree/bindings/iio/adc/ti,tsc2046.yaml +F: drivers/iio/adc/ti-tsc2046.c + TI TWL4030 SERIES SOC CODEC DRIVER M: Peter Ujfalusi L: alsa-devel@alsa-project.org (moderated for non-subscribers) diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 15587a1bc80d..6ad6f04dfd20 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -1175,6 +1175,18 @@ config TI_TLC4541 This driver can also be built as a module. If so, the module will be called ti-tlc4541. +config TI_TSC2046 + tristate "Texas Instruments TSC2046 ADC driver" + depends on SPI + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Say yes here to build support for ADC functionality of Texas + Instruments TSC2046 touch screen controller. + + This driver can also be built as a module. If so, the module will be + called ti-tsc2046. + config TWL4030_MADC tristate "TWL4030 MADC (Monitoring A/D Converter)" depends on TWL4030_CORE diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 5fca90ada0ec..440e18ac6780 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -105,6 +105,7 @@ obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o +obj-$(CONFIG_TI_TSC2046) += ti-tsc2046.o obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o obj-$(CONFIG_VF610_ADC) += vf610_adc.o diff --git a/drivers/iio/adc/ti-tsc2046.c b/drivers/iio/adc/ti-tsc2046.c new file mode 100644 index 000000000000..e119e7c31fa7 --- /dev/null +++ b/drivers/iio/adc/ti-tsc2046.c @@ -0,0 +1,652 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Texas Instruments TSC2046 SPI ADC driver + * + * Copyright (c) 2021 Oleksij Rempel , Pengutronix + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TI_TSC2046_NAME "tsc2046" + +/* this driver doesn't aim at the peak continuous sample rate */ +#define TI_TSC2046_MAX_SAMPLE_RATE 125000 +#define TI_TSC2046_SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/) +#define TI_TSC2046_MAX_CLK_FREQ \ + (TI_TSC2046_MAX_SAMPLE_RATE * TI_TSC2046_SAMPLE_BITS) + +/* + * Default settling time. This time depends on the: + * - PCB design + * - touch plates size, temperature, etc + * - initial power state of the ADC + * + * Since most values higher than 100us seems to be good, it make sense to + * have some default value. These values were measuring get by testing on a + * PLYM2M board at 2MHz SPI CLK rate. + * + * Sometimes there are extra signal filter capacitors on the touchscreen + * signals, which make it 10 or 100 times worse. + */ +#define TI_TSC2046_SETTLING_TIME_XYZ_DEF_US 700 +/* Oversampling count for the low-pass filter */ +#define TI_TSC2046_SAMPLES_XYZ_DEF 5 +/* Default sample interval */ +#define TI_TSC2046_SAMPLE_INTERVAL_US 10000 + +#define TI_TSC2046_START BIT(7) +#define TI_TSC2046_ADDR GENMASK(6, 4) +#define TI_TSC2046_ADDR_TEMP1 7 +#define TI_TSC2046_ADDR_AUX 6 +#define TI_TSC2046_ADDR_X 5 +#define TI_TSC2046_ADDR_Z2 4 +#define TI_TSC2046_ADDR_Z1 3 +#define TI_TSC2046_ADDR_VBAT 2 +#define TI_TSC2046_ADDR_Y 1 +#define TI_TSC2046_ADDR_TEMP0 0 + +/* + * The mode bit sets the resolution of the ADC. With this bit low, the next + * conversion has 12-bit resolution, whereas with this bit high, the next + * conversion has 8-bit resolution. This driver is optimized for 12-bit mode. + * So, for this driver, this bit should stay zero. + */ +#define TI_TSC2046_8BIT_MODE BIT(3) + +/* + * SER/DFR - The SER/DFR bit controls the reference mode, either single-ended + * (high) or differential (low). + */ +#define TI_TSC2046_SER BIT(2) + +/* + * If VREF_ON and ADC_ON are both zero, then the chip operates in + * auto-wake/suspend mode. In most case this bits should stay zero. + */ +#define TI_TSC2046_PD1_VREF_ON BIT(1) +#define TI_TSC2046_PD0_ADC_ON BIT(0) + +#define TI_TSC2046_MAX_CHAN 8 + +#define TI_TSC2046_TIMESTAMP_SIZE (sizeof(int64_t) / sizeof(int16_t)) + +/* represents a HW sample */ +struct tsc2046_adc_atom { + u8 cmd; + __be16 data; +} __packed; + +/* layout of atomic buffers within big buffer */ +struct tsc2046_adc_group_layout { + unsigned int offset; + unsigned int count; + unsigned int skip; +}; + +struct tsc2046_adc_dcfg { + const struct iio_chan_spec *channels; + unsigned int num_channels; +}; + +struct tsc2046_adc_priv { + struct spi_device *spi; + struct iio_trigger *trig; + const struct tsc2046_adc_dcfg *dcfg; + + struct spi_transfer xfer; + struct spi_message msg; + + u16 scan_buf[TI_TSC2046_MAX_CHAN + 2 + TI_TSC2046_TIMESTAMP_SIZE]; + /* + * Lock to protect the layout and the spi transfer buffer. + * tsc2046_adc_group_layout can be changed within update_scan_mode(), + * in this case the l[] and tx/rx buffer will be out of sync to each + * other. + */ + struct mutex slock; + struct tsc2046_adc_group_layout l[TI_TSC2046_MAX_CHAN]; + struct tsc2046_adc_atom *rx; + struct tsc2046_adc_atom *tx; + + unsigned int count; + unsigned int groups; + u32 effective_speed_hz; + u32 scan_interval_us; + u32 time_per_scan_us; + u32 time_per_bit_ns; +}; + +#define TI_TSC2046_V_CHAN(index, bits, name) \ +{ \ + .type = IIO_VOLTAGE, \ + .indexed = 1, \ + .channel = index, \ + .address = index, \ + .datasheet_name = "#name", \ + .scan_index = index, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = bits, \ + .storagebits = 16, \ + .shift = 0, \ + .endianness = IIO_CPU, \ + }, \ +} + +#define DECLARE_TI_TSC2046_8_CHANNELS(name, bits) \ +const struct iio_chan_spec name ## _channels[] = { \ + TI_TSC2046_V_CHAN(0, bits, TEMP0), \ + TI_TSC2046_V_CHAN(1, bits, Y), \ + TI_TSC2046_V_CHAN(2, bits, VBAT), \ + TI_TSC2046_V_CHAN(3, bits, Z1), \ + TI_TSC2046_V_CHAN(4, bits, Z2), \ + TI_TSC2046_V_CHAN(5, bits, X), \ + TI_TSC2046_V_CHAN(6, bits, AUX), \ + TI_TSC2046_V_CHAN(7, bits, TEMP1), \ + IIO_CHAN_SOFT_TIMESTAMP(8), \ +} + +static DECLARE_TI_TSC2046_8_CHANNELS(tsc2046_adc, 12); + +static const struct tsc2046_adc_dcfg tsc2046_adc_dcfg_tsc2046e = { + .channels = tsc2046_adc_channels, + .num_channels = ARRAY_SIZE(tsc2046_adc_channels), +}; + +/* + * Convert time to a number of samples which can be transferred within this + * time. + */ +static unsigned int tsc2046_adc_time_to_count(struct tsc2046_adc_priv *priv, + unsigned long time) +{ + unsigned int bit_count, sample_count; + + bit_count = DIV_ROUND_UP(time * NSEC_PER_USEC, priv->time_per_bit_ns); + sample_count = DIV_ROUND_UP(bit_count, TI_TSC2046_SAMPLE_BITS); + + dev_dbg(&priv->spi->dev, "%s effective speed %u, time per bit: %u, count bits: %u, count samples: %u\n", + __func__, priv->effective_speed_hz, priv->time_per_bit_ns, + bit_count, sample_count); + + return sample_count; +} + +/* + * In case this ADC is attached to a touchscreen, some channels will need more + * time to provide usable data than other channels. + */ +static unsigned int tsc2046_adc_get_settle_count(struct tsc2046_adc_priv *priv, + int ch_idx) +{ + u32 settle_time; + + switch (ch_idx) { + case TI_TSC2046_ADDR_X: + case TI_TSC2046_ADDR_Y: + case TI_TSC2046_ADDR_Z1: + case TI_TSC2046_ADDR_Z2: + settle_time = TI_TSC2046_SETTLING_TIME_XYZ_DEF_US; + break; + default: + settle_time = 0; + } + + return tsc2046_adc_time_to_count(priv, settle_time); +} + +static u8 tsc2046_adc_get_cmd(struct tsc2046_adc_priv *priv, int ch_idx, + bool keep_power) +{ + u32 pd = 0; /* power down (pd) bits */ + + /* + * if PD bits are 0, controller will automatically disable ADC, VREF and + * enable IRQ. + */ + if (keep_power) + pd = TI_TSC2046_PD0_ADC_ON; + + return TI_TSC2046_START | FIELD_PREP(TI_TSC2046_ADDR, ch_idx) | pd; +} + +static u16 tsc2046_adc_get_value(struct tsc2046_adc_atom *buf) +{ + /* last 3 bits on the wire are empty */ + return get_unaligned_be16(&buf->data) >> 3; +} + +static int tsc2046_adc_read_one(struct tsc2046_adc_priv *priv, int ch_idx, + u32 *effective_speed_hz) +{ + struct tsc2046_adc_atom tx_buf, rx_buf; + struct spi_transfer xfer; + struct spi_message msg; + int ret; + + memset(&xfer, 0, sizeof(xfer)); + tx_buf.cmd = tsc2046_adc_get_cmd(priv, ch_idx, false); + tx_buf.data = 0; + xfer.tx_buf = &tx_buf; + xfer.rx_buf = &rx_buf; + xfer.len = sizeof(tx_buf); + spi_message_init(&msg); + spi_message_add_tail(&xfer, &msg); + + ret = spi_sync(priv->spi, &msg); + if (ret) { + dev_err_ratelimited(&priv->spi->dev, "%s: SPI transfer filed %pe\n", + __func__, ERR_PTR(ret)); + return ret; + } + + if (effective_speed_hz) + *effective_speed_hz = xfer.effective_speed_hz; + + return tsc2046_adc_get_value(&rx_buf); +} + +static size_t tsc2046_adc_group_set_layout(struct tsc2046_adc_priv *priv, + unsigned int group, + unsigned int ch_idx) +{ + struct tsc2046_adc_group_layout *l = &priv->l[group]; + unsigned int max_count, count_skip; + unsigned int offset = 0; + + count_skip = tsc2046_adc_get_settle_count(priv, ch_idx); + + if (group != 0) { + l = &priv->l[group - 1]; + offset = l->offset + l->count; + } + + l = &priv->l[group]; + + max_count = count_skip + TI_TSC2046_SAMPLES_XYZ_DEF; + + l->offset = offset; + l->count = max_count; + l->skip = count_skip; + + return sizeof(*priv->tx) * max_count; +} + +static void tsc2046_adc_group_set_cmd(struct tsc2046_adc_priv *priv, + unsigned int group, int ch_idx) +{ + struct tsc2046_adc_group_layout *l = &priv->l[group]; + unsigned int i; + u8 cmd; + + /* + * Do not enable automatic power down on working samples. Otherwise the + * plates will never be completely charged. + */ + cmd = tsc2046_adc_get_cmd(priv, ch_idx, true); + + for (i = 0; i < l->count - 1; i++) + priv->tx[l->offset + i].cmd = cmd; + + /* automatically power down on last sample */ + priv->tx[l->offset + i].cmd = tsc2046_adc_get_cmd(priv, ch_idx, false); +} + +static int tsc2046_adc_get_valide_val(struct tsc2046_adc_priv *priv, + int group) +{ + struct tsc2046_adc_group_layout *l; + struct tsc2046_adc_atom *tx; + int ch_idx, valid_count, i; + unsigned int val, val_normalized = 0; + + l = &priv->l[group]; + tx = &priv->tx[l->offset + l->skip]; + ch_idx = FIELD_GET(TI_TSC2046_ADDR, tx->cmd); + + valid_count = l->count - l->skip; + for (i = 0; i < valid_count; i++) { + val = tsc2046_adc_get_value(&priv->rx[l->offset + l->skip + i]); + /* + * Following values are possible only if touch is not in active + * state. No pressure on plates. + */ + switch (ch_idx) { + case TI_TSC2046_ADDR_Y: + if (val == 0xfff) + return -EAGAIN; + break; + case TI_TSC2046_ADDR_X: + if (!val) + return -EAGAIN; + break; + } + + val_normalized += val; + } + + return DIV_ROUND_UP(val_normalized, valid_count); +} + +static int tsc2046_adc_scan(struct iio_dev *indio_dev) +{ + struct tsc2046_adc_priv *priv = iio_priv(indio_dev); + struct device *dev = &priv->spi->dev; + bool valid = true; + int group; + int ret; + + ret = spi_sync(priv->spi, &priv->msg); + if (ret < 0) { + dev_err_ratelimited(dev, "%s: SPI transfer filed: %pe\n", + __func__, ERR_PTR(ret)); + return ret; + } + + for (group = 0; group < priv->groups; group++) { + if (valid) { + /* + * Validate data to stop sampling and reduce power + * consumption. + */ + ret = tsc2046_adc_get_valide_val(priv, group); + if (ret < 0) { + /* go back and invalidate all channels */ + group = 0; + valid = false; + } + } else { + ret = 0xffff; + } + + priv->scan_buf[group] = ret; + } + + ret = iio_push_to_buffers_with_timestamp(indio_dev, &priv->scan_buf, + iio_get_time_ns(indio_dev)); + /* + * If there's no consumer (or consumer is too slow), we'll get a EBUSY + * here - ignore it. + */ + if (ret < 0 && ret != -EBUSY) { + dev_err_ratelimited(dev, "%s: Filed to push scan buffer %pe\n", + __func__, ERR_PTR(ret)); + + return ret; + } + + return valid ? 0 : -EAGAIN; +} + +static irqreturn_t tsc2046_adc_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct tsc2046_adc_priv *priv = iio_priv(indio_dev); + unsigned int retry = 3; + + do { + int ret, delta; + + mutex_lock(&priv->slock); + ret = tsc2046_adc_scan(indio_dev); + mutex_unlock(&priv->slock); + if (ret) + goto done; + + /* + * We can sample it as fast as we can, but usually we do not + * need so many samples. Reduce the sample rate for default + * (touchscreen) use case. + * Currently we do not need highly precise sample rate. It + * is enough to have calculated numbers. + */ + delta = priv->scan_interval_us - priv->time_per_scan_us; + if (delta > 0) + fsleep(delta); + } while (retry--); + +done: + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static int tsc2046_adc_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *active_scan_mask) +{ + struct tsc2046_adc_priv *priv = iio_priv(indio_dev); + unsigned int ch_idx, group = 0; + size_t size = 0; + + mutex_lock(&priv->slock); + + for_each_set_bit(ch_idx, active_scan_mask, indio_dev->num_channels) { + size += tsc2046_adc_group_set_layout(priv, group, ch_idx); + tsc2046_adc_group_set_cmd(priv, group, ch_idx); + group++; + } + + priv->groups = group; + priv->xfer.len = size; + priv->time_per_scan_us = size * 8 * + priv->time_per_bit_ns / NSEC_PER_USEC; + + if ((priv->scan_interval_us - priv->time_per_scan_us) < 0) + dev_warn(&priv->spi->dev, "The scan interval (%d) is less then calculated scan time (%d)\n", + priv->scan_interval_us, priv->time_per_scan_us); + + mutex_unlock(&priv->slock); + + return 0; +} + +static const struct iio_info tsc2046_adc_info = { + .update_scan_mode = tsc2046_adc_update_scan_mode, +}; + +static irqreturn_t tsc2046_adc_irq(int irq, void *dev_id) +{ + struct iio_dev *indio_dev = dev_id; + struct tsc2046_adc_priv *priv = iio_priv(indio_dev); + + iio_trigger_poll_chained(priv->trig); + + return IRQ_HANDLED; +} + +static int tsc2046_adc_set_trigger_state(struct iio_trigger *trig, bool enable) +{ + struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); + struct tsc2046_adc_priv *priv = iio_priv(indio_dev); + + if (enable) + enable_irq(priv->spi->irq); + else + disable_irq(priv->spi->irq); + + return 0; +} + +static const struct iio_trigger_ops tsc2046_adc_trigger_ops = { + .set_trigger_state = tsc2046_adc_set_trigger_state, +}; + +static int tsc2046_adc_setup_spi_msg(struct tsc2046_adc_priv *priv) +{ + unsigned int ch_idx; + size_t size = 0; + int ret; + + /* + * Make dummy read to set initial power state and get real SPI clock + * freq. It seems to be not important which channel is used for this + * case. + */ + ret = tsc2046_adc_read_one(priv, TI_TSC2046_ADDR_TEMP0, + &priv->effective_speed_hz); + if (ret < 0) + return ret; + + /* + * In case SPI controller do not report effective_speed_hz, use + * configure value and hope it will match + */ + if (!priv->effective_speed_hz) + priv->effective_speed_hz = priv->spi->max_speed_hz; + + + priv->scan_interval_us = TI_TSC2046_SAMPLE_INTERVAL_US; + priv->time_per_bit_ns = DIV_ROUND_UP(NSEC_PER_SEC, + priv->effective_speed_hz); + + /* + * calculate and allocate maximal size buffer if all channels are + * enabled + */ + for (ch_idx = 0; ch_idx < priv->dcfg->num_channels; ch_idx++) + size += tsc2046_adc_group_set_layout(priv, ch_idx, ch_idx); + + priv->tx = devm_kzalloc(&priv->spi->dev, size, GFP_KERNEL); + if (!priv->tx) + return -ENOMEM; + + priv->rx = devm_kzalloc(&priv->spi->dev, size, GFP_KERNEL); + if (!priv->rx) + return -ENOMEM; + + spi_message_init(&priv->msg); + priv->msg.context = priv; + + priv->xfer.tx_buf = priv->tx; + priv->xfer.rx_buf = priv->rx; + priv->xfer.len = size; + spi_message_add_tail(&priv->xfer, &priv->msg); + + return 0; +} + +static int tsc2046_adc_probe(struct spi_device *spi) +{ + const struct tsc2046_adc_dcfg *dcfg; + struct device *dev = &spi->dev; + struct tsc2046_adc_priv *priv; + struct iio_dev *indio_dev; + struct iio_trigger *trig; + const char *name; + int ret; + + /* don't exceed max specified sample rate */ + if (spi->max_speed_hz > TI_TSC2046_MAX_CLK_FREQ) { + dev_err(dev, "SPI max_speed_hz is too high: %d Hz. Max supported freq is %d Hz\n", + spi->max_speed_hz, TI_TSC2046_MAX_CLK_FREQ); + return -EINVAL; + } + + dcfg = device_get_match_data(dev); + if (!dcfg) + return -EINVAL; + + spi->bits_per_word = 8; + spi->mode &= ~SPI_MODE_X_MASK; + spi->mode |= SPI_MODE_0; + ret = spi_setup(spi); + if (ret < 0) + return dev_err_probe(dev, ret, "Error in spi setup\n"); + + indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); + if (!indio_dev) + return -ENOMEM; + + priv = iio_priv(indio_dev); + priv->dcfg = dcfg; + + spi_set_drvdata(spi, indio_dev); + + priv->spi = spi; + + name = devm_kasprintf(dev, GFP_KERNEL, "%s-%s", + TI_TSC2046_NAME, dev_name(dev)); + + indio_dev->name = name; + indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED; + indio_dev->channels = dcfg->channels; + indio_dev->num_channels = dcfg->num_channels; + indio_dev->info = &tsc2046_adc_info; + + ret = tsc2046_adc_setup_spi_msg(priv); + if (ret) + return ret; + + mutex_init(&priv->slock); + + /* TODO: remove IRQ_NOAUTOEN after needed patches are mainline */ + irq_set_status_flags(spi->irq, IRQ_NOAUTOEN); + ret = devm_request_threaded_irq(dev, spi->irq, + NULL, + &tsc2046_adc_irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + name, indio_dev); + if (ret) + return ret; + + trig = devm_iio_trigger_alloc(dev, "%s-dev%d", + indio_dev->name, indio_dev->id); + if (!trig) + return -ENOMEM; + + priv->trig = trig; + trig->dev.parent = indio_dev->dev.parent; + iio_trigger_set_drvdata(trig, indio_dev); + trig->ops = &tsc2046_adc_trigger_ops; + + ret = devm_iio_trigger_register(dev, trig); + if (ret) { + dev_err(dev, "failed to register trigger\n"); + return ret; + } + + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, + &tsc2046_adc_trigger_handler, NULL); + if (ret) { + dev_err(dev, "Failed to setup triggered buffer\n"); + return ret; + } + + ret = devm_iio_device_register(dev, indio_dev); + if (ret) { + dev_err(dev, "Failed to register iio device\n"); + return ret; + } + + /* set default trigger */ + indio_dev->trig = iio_trigger_get(priv->trig); + return 0; +} + +static const struct of_device_id ads7950_of_table[] = { + { .compatible = "ti,tsc2046e-adc", .data = &tsc2046_adc_dcfg_tsc2046e }, + { }, +}; +MODULE_DEVICE_TABLE(of, ads7950_of_table); + +static struct spi_driver tsc2046_adc_driver = { + .driver = { + .name = "tsc2046", + .of_match_table = ads7950_of_table, + }, + .probe = tsc2046_adc_probe, +}; +module_spi_driver(tsc2046_adc_driver); + +MODULE_AUTHOR("Oleksij Rempel "); +MODULE_DESCRIPTION("TI TSC2046 ADC"); +MODULE_LICENSE("GPL v2");