[PATCH v2 2/2] ASoC: Add initial ZL38060 driver

From: Sven Van Asbroeck <thesven73@gmail.com>
To: Rob Herring <robh+dt@kernel.org>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>,
	Mark Brown <broonie@kernel.org>,
	alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/2] ASoC: Add initial ZL38060 driver
Date: Fri, 17 Apr 2020 18:13:41 -0400	[thread overview]
Message-ID: <20200417221341.31428-2-TheSven73@gmail.com> (raw)
In-Reply-To: <20200417221341.31428-1-TheSven73@gmail.com>

The ZL38060 is a "Connected Home Audio Processor" from Microsemi,
which consists of a Digital Signal Processor (DSP), several Digital
Audio Interfaces (DAIs), analog outputs, and a block of 14 GPIOs.

This driver supports only a tiny subset of the chip's functionality
and possible configurations:
- bypass mode (whole dsp block is bypassed)
- chip's I2S DAI routed directly to/from DACs and microphone
- chip's internal clock is driven by a 12 MHz external crystal
- chip's DAI connected to CPU is I2S, and bit + frame clock master
- chip must be strapped for "host boot": in this mode, firmware will
  be provided by this driver.

Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
---

Tree: v5.7-rc1

v1->v2:

Mark Brown:

- fixup comment style at top of file.

- fixup curly braces in if-elseif-else statement.

- explicitly put the chip in reset so it reverts to a known state.
  
- remove 'mscc,load-firmware' devicetree property, which provided support for
  switching between chip bootstrap modes (host boot / auto boot from external
  flash).
  On reflection, I cannot test correct operation of auto-boot - it involves
  interaction with the Bootloader Status Register, and I have no access to an
  auto-boot zl38060.
  This means the only tested and supported mode will be 'host boot', where the
  firmware is programmed by the host CPU (ie. Linux).

- remove amplifier enable gpio. if required, it should be part of the machine
  layer.

Sven Van Asbroeck:

- add dapm widgets: DAC1, DAC2, DMICL. Routed to Playback and Capture,
  respectively. This is required to drive a microphone amp-enable gpio
  from the machine layer.


 sound/soc/codecs/Kconfig   |  11 +
 sound/soc/codecs/Makefile  |   2 +
 sound/soc/codecs/zl38060.c | 638 +++++++++++++++++++++++++++++++++++++
 3 files changed, 651 insertions(+)
 create mode 100644 sound/soc/codecs/zl38060.c

diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
index e6a0c5d05fa5..7cb032757d32 100644
--- a/sound/soc/codecs/Kconfig
+++ b/sound/soc/codecs/Kconfig
@@ -272,6 +272,7 @@ config SND_SOC_ALL_CODECS
 	imply SND_SOC_WM9712
 	imply SND_SOC_WM9713
 	imply SND_SOC_WSA881X
+	imply SND_SOC_ZL38060
 	help
 	  Normally ASoC codec drivers are only built if a machine driver which
 	  uses them is also built since they are only usable with a machine
@@ -1642,6 +1643,16 @@ config SND_SOC_WSA881X
 	  This enables support for Qualcomm WSA8810/WSA8815 Class-D
 	  Smart Speaker Amplifier.
 
+config SND_SOC_ZL38060
+	tristate "Microsemi ZL38060 Connected Home Audio Processor"
+	depends on SPI_MASTER
+	select GPIOLIB
+	select REGMAP
+	help
+	  Support for ZL38060 Connected Home Audio Processor from Microsemi,
+	  which consists of a Digital Signal Processor (DSP), several Digital
+	  Audio Interfaces (DAIs), analog outputs, and a block of 14 GPIOs.
+
 config SND_SOC_ZX_AUD96P22
 	tristate "ZTE ZX AUD96P22 CODEC"
 	depends on I2C
diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
index 03533157cda6..a603532c7af5 100644
--- a/sound/soc/codecs/Makefile
+++ b/sound/soc/codecs/Makefile
@@ -288,6 +288,7 @@ snd-soc-wm9712-objs := wm9712.o
 snd-soc-wm9713-objs := wm9713.o
 snd-soc-wm-hubs-objs := wm_hubs.o
 snd-soc-wsa881x-objs := wsa881x.o
+snd-soc-zl38060-objs := zl38060.o
 snd-soc-zx-aud96p22-objs := zx_aud96p22.o
 # Amp
 snd-soc-max9877-objs := max9877.o
@@ -588,6 +589,7 @@ obj-$(CONFIG_SND_SOC_WM9713)	+= snd-soc-wm9713.o
 obj-$(CONFIG_SND_SOC_WM_ADSP)	+= snd-soc-wm-adsp.o
 obj-$(CONFIG_SND_SOC_WM_HUBS)	+= snd-soc-wm-hubs.o
 obj-$(CONFIG_SND_SOC_WSA881X)	+= snd-soc-wsa881x.o
+obj-$(CONFIG_SND_SOC_ZL38060)	+= snd-soc-zl38060.o
 obj-$(CONFIG_SND_SOC_ZX_AUD96P22) += snd-soc-zx-aud96p22.o
 
 # Amp
diff --git a/sound/soc/codecs/zl38060.c b/sound/soc/codecs/zl38060.c
new file mode 100644
index 000000000000..927ad849ad2d
--- /dev/null
+++ b/sound/soc/codecs/zl38060.c
@@ -0,0 +1,638 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Codec driver for Microsemi ZL38060 Connected Home Audio Processor.
+//
+// Copyright(c) 2020 Sven Van Asbroeck
+
+// The ZL38060 is very flexible and configurable. This driver implements only a
+// tiny subset of the chip's possible configurations:
+//
+// - DSP block bypassed: DAI        routed straight to DACs
+//                       microphone routed straight to DAI
+// - chip's internal clock is driven by a 12 MHz external crystal
+// - chip's DAI connected to CPU is I2S, and bit + frame clock master
+// - chip must be strapped for "host boot": in this mode, firmware will be
+//   provided by this driver.
+
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+#include <linux/module.h>
+#include <linux/ihex.h>
+
+#include <sound/pcm_params.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+
+#define DRV_NAME		"zl38060"
+
+#define ZL38_RATES		(SNDRV_PCM_RATE_8000  |\
+				SNDRV_PCM_RATE_16000 |\
+				SNDRV_PCM_RATE_48000)
+#define ZL38_FORMATS		SNDRV_PCM_FMTBIT_S16_LE
+
+#define HBI_FIRMWARE_PAGE	0xFF
+#define ZL38_MAX_RAW_XFER	0x100
+
+#define REG_TDMA_CFG_CLK	0x0262
+#define CFG_CLK_PCLK_SHIFT	4
+#define CFG_CLK_PCLK_MASK	(0x7ff << CFG_CLK_PCLK_SHIFT)
+#define CFG_CLK_PCLK(bits)	((bits - 1) << CFG_CLK_PCLK_SHIFT)
+#define CFG_CLK_MASTER		BIT(15)
+#define CFG_CLK_FSRATE_MASK	0x7
+#define CFG_CLK_FSRATE_8KHZ	0x1
+#define CFG_CLK_FSRATE_16KHZ	0x2
+#define CFG_CLK_FSRATE_48KHZ	0x6
+
+#define REG_CLK_CFG		0x0016
+#define CLK_CFG_SOURCE_XTAL	BIT(15)
+
+#define REG_CLK_STATUS		0x0014
+#define CLK_STATUS_HWRST	BIT(0)
+
+#define REG_PARAM_RESULT	0x0034
+#define PARAM_RESULT_READY	0xD3D3
+
+#define REG_PG255_BASE_HI	0x000C
+#define REG_PG255_OFFS(addr)	((HBI_FIRMWARE_PAGE << 8) | (addr & 0xFF))
+#define REG_FWR_EXEC		0x012C
+
+#define REG_CMD			0x0032
+#define REG_HW_REV		0x0020
+#define REG_FW_PROD		0x0022
+#define REG_FW_REV		0x0024
+
+#define REG_SEMA_FLAGS		0x0006
+#define SEMA_FLAGS_BOOT_CMD	BIT(0)
+#define SEMA_FLAGS_APP_REBOOT	BIT(1)
+
+#define REG_HW_REV		0x0020
+#define REG_FW_PROD		0x0022
+#define REG_FW_REV		0x0024
+#define REG_GPIO_DIR		0x02DC
+#define REG_GPIO_DAT		0x02DA
+
+#define BOOTCMD_LOAD_COMPLETE	0x000D
+#define BOOTCMD_FW_GO		0x0008
+
+#define FIRMWARE_MAJOR		2
+#define FIRMWARE_MINOR		2
+
+struct zl38_codec_priv {
+	struct device *dev;
+	struct regmap *regmap;
+	bool is_stream_in_use[2];
+	struct gpio_chip *gpio_chip;
+};
+
+static int zl38_fw_issue_command(struct regmap *regmap, u16 cmd)
+{
+	unsigned int val;
+	int err;
+
+	err = regmap_read_poll_timeout(regmap, REG_SEMA_FLAGS, val,
+				       !(val & SEMA_FLAGS_BOOT_CMD), 10000,
+				       10000 * 100);
+	if (err)
+		return err;
+	err = regmap_write(regmap, REG_CMD, cmd);
+	if (err)
+		return err;
+	err = regmap_update_bits(regmap, REG_SEMA_FLAGS, SEMA_FLAGS_BOOT_CMD,
+				 SEMA_FLAGS_BOOT_CMD);
+	if (err)
+		return err;
+
+	return regmap_read_poll_timeout(regmap, REG_CMD, val, !val, 10000,
+					10000 * 100);
+}
+
+static int zl38_fw_go(struct regmap *regmap)
+{
+	int err;
+
+	err = zl38_fw_issue_command(regmap, BOOTCMD_LOAD_COMPLETE);
+	if (err)
+		return err;
+
+	return zl38_fw_issue_command(regmap, BOOTCMD_FW_GO);
+}
+
+static int zl38_fw_enter_boot_mode(struct regmap *regmap)
+{
+	unsigned int val;
+	int err;
+
+	err = regmap_update_bits(regmap, REG_CLK_STATUS, CLK_STATUS_HWRST,
+				 CLK_STATUS_HWRST);
+	if (err)
+		return err;
+
+	return regmap_read_poll_timeout(regmap, REG_PARAM_RESULT, val,
+					val == PARAM_RESULT_READY, 1000, 50000);
+}
+
+static int
+zl38_fw_send_data(struct regmap *regmap, u32 addr, const void *data, u16 len)
+{
+	__be32 addr_base = cpu_to_be32(addr & ~0xFF);
+	int err;
+
+	err = regmap_raw_write(regmap, REG_PG255_BASE_HI, &addr_base,
+			       sizeof(addr_base));
+	if (err)
+		return err;
+	return regmap_raw_write(regmap, REG_PG255_OFFS(addr), data, len);
+}
+
+static int zl38_fw_send_xaddr(struct regmap *regmap, const void *data)
+{
+	/* execution address from ihex: 32-bit little endian.
+	 * device register expects 32-bit big endian.
+	 */
+	u32 addr = le32_to_cpup(data);
+	__be32 baddr = cpu_to_be32(addr);
+
+	return regmap_raw_write(regmap, REG_FWR_EXEC, &baddr, sizeof(baddr));
+}
+
+static int zl38_load_firmware(struct device *dev, struct regmap *regmap)
+{
+	const struct ihex_binrec *rec;
+	const struct firmware *fw;
+	u32 addr;
+	u16 len;
+	int err;
+
+	/* how to get this firmware:
+	 * 1. request and download chip firmware from Microsemi
+	 *    (provided by Microsemi in srec format)
+	 * 2. convert downloaded firmware from srec to ihex. Simple tool:
+	 *    https://gitlab.com/TheSven73/s3-to-irec
+	 * 3. convert ihex to binary (.fw) using ihex2fw tool which is included
+	 *    with the Linux kernel sources
+	 */
+	err = request_ihex_firmware(&fw, "zl38060.fw", dev);
+	if (err)
+		return err;
+	err = zl38_fw_enter_boot_mode(regmap);
+	if (err)
+		goto out;
+	rec = (const struct ihex_binrec *)fw->data;
+	while (rec) {
+		addr = be32_to_cpu(rec->addr);
+		len = be16_to_cpu(rec->len);
+		if (addr) {
+			/* regular data ihex record */
+			err = zl38_fw_send_data(regmap, addr, rec->data, len);
+		} else if (len == 4) {
+			/* execution address ihex record */
+			err = zl38_fw_send_xaddr(regmap, rec->data);
+		} else {
+			err = -EINVAL;
+		}
+		if (err)
+			goto out;
+		/* next ! */
+		rec = ihex_next_binrec(rec);
+	}
+	err = zl38_fw_go(regmap);
+
+out:
+	release_firmware(fw);
+	return err;
+}
+
+
+static int zl38_software_reset(struct regmap *regmap)
+{
+	unsigned int val;
+	int err;
+
+	err = regmap_update_bits(regmap, REG_SEMA_FLAGS, SEMA_FLAGS_APP_REBOOT,
+				 SEMA_FLAGS_APP_REBOOT);
+	if (err)
+		return err;
+
+	/* wait for host bus interface to settle.
+	 * Not sure if this is required: Microsemi's vendor driver does this,
+	 * but the firmware manual does not mention it. Leave it in, there's
+	 * little downside, apart from a slower reset.
+	 */
+	msleep(50);
+
+	return regmap_read_poll_timeout(regmap, REG_SEMA_FLAGS, val,
+					!(val & SEMA_FLAGS_APP_REBOOT), 10000,
+					10000 * 100);
+}
+
+static int zl38_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct zl38_codec_priv *priv = snd_soc_dai_get_drvdata(dai);
+	int err;
+
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		/* firmware default is normal i2s */
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		/* firmware default is normal bitclock and frame */
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBM_CFM:
+		/* always 32 bits per frame (= 16 bits/channel, 2 channels) */
+		err = regmap_update_bits(priv->regmap, REG_TDMA_CFG_CLK,
+					 CFG_CLK_MASTER | CFG_CLK_PCLK_MASK,
+					 CFG_CLK_MASTER | CFG_CLK_PCLK(32));
+		if (err)
+			return err;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int zl38_hw_params(struct snd_pcm_substream *substream,
+			  struct snd_pcm_hw_params *params,
+			  struct snd_soc_dai *dai)
+{
+	struct zl38_codec_priv *priv = snd_soc_dai_get_drvdata(dai);
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+	unsigned int fsrate;
+	int err;
+
+	/* We cannot change hw_params while the dai is already in use - the
+	 * software reset will corrupt the audio. However, this is not required,
+	 * as the chip's TDM buses are fully symmetric, which mandates identical
+	 * rates, channels, and samplebits for record and playback.
+	 */
+	if (priv->is_stream_in_use[!tx])
+		goto skip_setup;
+
+	switch (params_rate(params)) {
+	case 8000:
+		fsrate = CFG_CLK_FSRATE_8KHZ;
+		break;
+	case 16000:
+		fsrate = CFG_CLK_FSRATE_16KHZ;
+		break;
+	case 48000:
+		fsrate = CFG_CLK_FSRATE_48KHZ;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	err = regmap_update_bits(priv->regmap, REG_TDMA_CFG_CLK,
+				 CFG_CLK_FSRATE_MASK, fsrate);
+	if (err)
+		return err;
+
+	/* chip requires a software reset to apply audio register changes */
+	err = zl38_software_reset(priv->regmap);
+	if (err)
+		return err;
+
+skip_setup:
+	priv->is_stream_in_use[tx] = true;
+
+	return 0;
+}
+
+static int zl38_hw_free(struct snd_pcm_substream *substream,
+			struct snd_soc_dai *dai)
+{
+	struct zl38_codec_priv *priv = snd_soc_dai_get_drvdata(dai);
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+
+	priv->is_stream_in_use[tx] = false;
+
+	return 0;
+}
+
+/* stereo bypass with no AEC */
+static const struct reg_sequence cp_config_stereo_bypass[] = {
+	/* interconnects must be programmed first */
+	{ 0x0210, 0x0005 },	/* DAC1   in <= I2S1-L */
+	{ 0x0212, 0x0006 },	/* DAC2   in <= I2S1-R */
+	{ 0x0214, 0x0001 },	/* I2S1-L in <= MIC1   */
+	{ 0x0216, 0x0001 },	/* I2S1-R in <= MIC1   */
+	{ 0x0224, 0x0000 },	/* AEC-S  in <= n/a    */
+	{ 0x0226, 0x0000 },	/* AEC-R  in <= n/a    */
+	/* output enables must be programmed next */
+	{ 0x0202, 0x000F },	/* enable I2S1 + DAC   */
+};
+
+static const struct snd_soc_dai_ops zl38_dai_ops = {
+	.set_fmt = zl38_set_fmt,
+	.hw_params = zl38_hw_params,
+	.hw_free = zl38_hw_free,
+};
+
+static struct snd_soc_dai_driver zl38_dai = {
+	.name = "zl38060-tdma",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = ZL38_RATES,
+		.formats = ZL38_FORMATS,
+	},
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = ZL38_RATES,
+		.formats = ZL38_FORMATS,
+	},
+	.ops = &zl38_dai_ops,
+	.symmetric_rates = 1,
+	.symmetric_samplebits = 1,
+	.symmetric_channels = 1,
+};
+
+static const struct snd_soc_dapm_widget zl38_dapm_widgets[] = {
+	SND_SOC_DAPM_OUTPUT("DAC1"),
+	SND_SOC_DAPM_OUTPUT("DAC2"),
+
+	SND_SOC_DAPM_INPUT("DMICL"),
+};
+
+static const struct snd_soc_dapm_route zl38_dapm_routes[] = {
+	{ "DAC1",  NULL, "Playback" },
+	{ "DAC2",  NULL, "Playback" },
+
+	{ "Capture",  NULL, "DMICL" },
+};
+
+static const struct snd_soc_component_driver zl38_component_dev = {
+	.dapm_widgets		= zl38_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(zl38_dapm_widgets),
+	.dapm_routes		= zl38_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(zl38_dapm_routes),
+	.endianness		= 1,
+	.non_legacy_dai_naming	= 1,
+};
+
+static void chip_gpio_set(struct gpio_chip *c, unsigned int offset, int val)
+{
+	struct regmap *regmap = gpiochip_get_data(c);
+	unsigned int mask = BIT(offset);
+
+	regmap_update_bits(regmap, REG_GPIO_DAT, mask, val ? mask : 0);
+}
+
+static int chip_gpio_get(struct gpio_chip *c, unsigned int offset)
+{
+	struct regmap *regmap = gpiochip_get_data(c);
+	unsigned int mask = BIT(offset);
+	unsigned int val;
+	int err;
+
+	err = regmap_read(regmap, REG_GPIO_DAT, &val);
+	if (err)
+		return err;
+
+	return !!(val & mask);
+}
+
+static int chip_direction_input(struct gpio_chip *c, unsigned int offset)
+{
+	struct regmap *regmap = gpiochip_get_data(c);
+	unsigned int mask = BIT(offset);
+
+	return regmap_update_bits(regmap, REG_GPIO_DIR, mask, 0);
+}
+
+static int
+chip_direction_output(struct gpio_chip *c, unsigned int offset, int val)
+{
+	struct regmap *regmap = gpiochip_get_data(c);
+	unsigned int mask = BIT(offset);
+
+	chip_gpio_set(c, offset, val);
+	return regmap_update_bits(regmap, REG_GPIO_DIR, mask, mask);
+}
+
+static const struct gpio_chip template_chip = {
+	.owner = THIS_MODULE,
+	.label = DRV_NAME,
+
+	.base = -1,
+	.ngpio = 14,
+	.direction_input = chip_direction_input,
+	.direction_output = chip_direction_output,
+	.get = chip_gpio_get,
+	.set = chip_gpio_set,
+
+	.can_sleep = true,
+};
+
+static int zl38_check_revision(struct device *dev, struct regmap *regmap)
+{
+	unsigned int hwrev, fwprod, fwrev;
+	int fw_major, fw_minor, fw_micro;
+	int err;
+
+	err = regmap_read(regmap, REG_HW_REV, &hwrev);
+	if (err)
+		return err;
+	err = regmap_read(regmap, REG_FW_PROD, &fwprod);
+	if (err)
+		return err;
+	err = regmap_read(regmap, REG_FW_REV, &fwrev);
+	if (err)
+		return err;
+
+	fw_major = (fwrev >> 12) & 0xF;
+	fw_minor = (fwrev >>  8) & 0xF;
+	fw_micro = fwrev & 0xFF;
+	dev_info(dev, "hw rev 0x%x, fw product code %d, firmware rev %d.%d.%d",
+		 hwrev & 0x1F, fwprod, fw_major, fw_minor, fw_micro);
+
+	if (fw_major != FIRMWARE_MAJOR || fw_minor < FIRMWARE_MINOR) {
+		dev_err(dev, "unsupported firmware. driver supports %d.%d",
+			FIRMWARE_MAJOR, FIRMWARE_MINOR);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int zl38_bus_read(void *context,
+			 const void *reg_buf, size_t reg_size,
+			 void *val_buf, size_t val_size)
+{
+	struct spi_device *spi = context;
+	const u8 *reg_buf8 = reg_buf;
+	size_t len = 0;
+	u8 offs, page;
+	u8 txbuf[4];
+
+	if (reg_size != 2 || val_size > ZL38_MAX_RAW_XFER)
+		return -EINVAL;
+
+	offs = reg_buf8[1] >> 1;
+	page = reg_buf8[0];
+
+	if (page) {
+		txbuf[len++] = 0xFE;
+		txbuf[len++] = page == HBI_FIRMWARE_PAGE ? 0xFF : page - 1;
+		txbuf[len++] = offs;
+		txbuf[len++] = val_size / 2 - 1;
+	} else {
+		txbuf[len++] = offs | 0x80;
+		txbuf[len++] = val_size / 2 - 1;
+	}
+
+	return spi_write_then_read(spi, txbuf, len, val_buf, val_size);
+}
+
+static int zl38_bus_write(void *context, const void *data, size_t count)
+{
+	struct spi_device *spi = context;
+	u8 buf[4 + ZL38_MAX_RAW_XFER];
+	size_t val_len, len = 0;
+	const u8 *data8 = data;
+	u8 offs, page;
+
+	if (count > (2 + ZL38_MAX_RAW_XFER) || count < 4)
+		return -EINVAL;
+	val_len = count - 2;
+	offs = data8[1] >> 1;
+	page = data8[0];
+
+	if (page) {
+		buf[len++] = 0xFE;
+		buf[len++] = page == HBI_FIRMWARE_PAGE ? 0xFF : page - 1;
+		buf[len++] = offs;
+		buf[len++] = (val_len / 2 - 1) | 0x80;
+	} else {
+		buf[len++] = offs | 0x80;
+		buf[len++] = (val_len / 2 - 1) | 0x80;
+	}
+	memcpy(buf + len, data8 + 2, val_len);
+	len += val_len;
+
+	return spi_write(spi, buf, len);
+}
+
+static const struct regmap_bus zl38_regmap_bus = {
+	.read = zl38_bus_read,
+	.write = zl38_bus_write,
+	.max_raw_write = ZL38_MAX_RAW_XFER,
+	.max_raw_read = ZL38_MAX_RAW_XFER,
+};
+
+static const struct regmap_config zl38_regmap_conf = {
+	.reg_bits = 16,
+	.val_bits = 16,
+	.reg_stride = 2,
+	.use_single_read = true,
+	.use_single_write = true,
+};
+
+static int zl38_spi_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct zl38_codec_priv *priv;
+	struct gpio_desc *reset_gpio;
+	int err;
+
+	/* get the chip to a known state by putting it in reset */
+	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(reset_gpio))
+		return PTR_ERR(reset_gpio);
+	if (reset_gpio) {
+		/* datasheet: need > 10us for a digital + analog reset */
+		usleep_range(15, 50);
+		/* take the chip out of reset */
+		gpiod_set_value_cansleep(reset_gpio, 0);
+		/* datasheet: need > 3ms for digital section to become stable */
+		usleep_range(3000, 10000);
+	}
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	dev_set_drvdata(dev, priv);
+	priv->regmap = devm_regmap_init(dev, &zl38_regmap_bus, spi,
+					&zl38_regmap_conf);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	err = zl38_load_firmware(dev, priv->regmap);
+	if (err)
+		return err;
+
+	err = zl38_check_revision(dev, priv->regmap);
+	if (err)
+		return err;
+
+	priv->gpio_chip = devm_kmemdup(dev, &template_chip,
+				       sizeof(template_chip), GFP_KERNEL);
+	if (!priv->gpio_chip)
+		return -ENOMEM;
+#ifdef CONFIG_OF_GPIO
+	priv->gpio_chip->of_node = dev->of_node;
+#endif
+	err = devm_gpiochip_add_data(dev, priv->gpio_chip, priv->regmap);
+	if (err)
+		return err;
+
+	/* setup the cross-point switch for stereo bypass */
+	err = regmap_multi_reg_write(priv->regmap, cp_config_stereo_bypass,
+				     ARRAY_SIZE(cp_config_stereo_bypass));
+	if (err)
+		return err;
+	/* setup for 12MHz crystal connected to the chip */
+	err = regmap_update_bits(priv->regmap, REG_CLK_CFG, CLK_CFG_SOURCE_XTAL,
+				 CLK_CFG_SOURCE_XTAL);
+	if (err)
+		return err;
+
+	return devm_snd_soc_register_component(dev, &zl38_component_dev,
+					       &zl38_dai, 1);
+}
+
+static const struct of_device_id zl38_dt_ids[] = {
+	{ .compatible = "mscc,zl38060", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, zl38_dt_ids);
+
+static const struct spi_device_id zl38_spi_ids[] = {
+	{ "zl38060", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, zl38_spi_ids);
+
+static struct spi_driver zl38060_spi_driver = {
+	.driver	= {
+		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(zl38_dt_ids),
+	},
+	.probe = zl38_spi_probe,
+	.id_table = zl38_spi_ids,
+};
+module_spi_driver(zl38060_spi_driver);
+
+MODULE_DESCRIPTION("ASoC ZL38060 driver");
+MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

