RE: [PATCH v2 5/6] spi: cs42l43: Add SPI controller support

[Mahapatra, Amit Kumar]

Hello,


> -----Original Message-----
> From: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
> Sent: Tuesday, May 30, 2023 5:51 PM
> To: broonie@xxxxxxxxxx; lee@xxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx;
> linus.walleij@xxxxxxxxxx; vkoul@xxxxxxxxxx
> Cc: robh+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx; lgirdwood@xxxxxxxxx; yung-
> chuan.liao@xxxxxxxxxxxxxxx; sanyog.r.kale@xxxxxxxxx; pierre-
> louis.bossart@xxxxxxxxxxxxxxx; alsa-devel@xxxxxxxxxxxxxxxx;
> patches@xxxxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> gpio@xxxxxxxxxxxxxxx; linux-spi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH v2 5/6] spi: cs42l43: Add SPI controller support
> 
> CAUTION: This message has originated from an External Source. Please use
> proper judgment and caution when opening attachments, clicking links, or
> responding to this email.
> 
> 
> From: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
> 
> The CS42L43 is an audio CODEC with integrated MIPI SoundWire interface
> (Version 1.2.1 compliant), I2C, SPI, and I2S/TDM interfaces designed for
> portable applications. It provides a high dynamic range, stereo DAC for
> headphone output, two integrated Class D amplifiers for loudspeakers, and
> two ADCs for wired headset microphone input or stereo line input. PDM
> inputs are provided for digital microphones.
> 
> The SPI component incorporates a SPI controller interface for communication
> with other peripheral components.
> 
> Signed-off-by: Lucas Tanure <tanureal@xxxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Maciej Strozek <mstrozek@xxxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
> ---
> 
> Changes since v1:
>  - Use HZ_PER_MHZ
>  - Return ret in un/prepare_transfer_hardware
>  - Use SPI_MODE_X_MASK
>  - Use devm_pm_runtime_enable
>  - Switch to using a platform_device_id table
>  - Use device_set_node
>  - Use min rather than min_t, and updating some consts to make it work
> 
> Thanks,
> Charles
> 
>  MAINTAINERS               |   1 +
>  drivers/spi/Kconfig       |   7 +
>  drivers/spi/Makefile      |   1 +
>  drivers/spi/spi-cs42l43.c | 279 ++++++++++++++++++++++++++++++++++++++
>  4 files changed, 288 insertions(+)
>  create mode 100644 drivers/spi/spi-cs42l43.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ed26f63087342..a30dfbeb4f57a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4930,6 +4930,7 @@ F:
> Documentation/devicetree/bindings/mfd/cirrus,cs*
>  F:     Documentation/devicetree/bindings/sound/cirrus,cs*
>  F:     drivers/mfd/cs42l43*
>  F:     drivers/pinctrl/cirrus/pinctrl-cs42l43*
> +F:     drivers/spi/spi-cs42l43*
>  F:     include/dt-bindings/sound/cs*
>  F:     include/linux/mfd/cs42l43*
>  F:     include/sound/cs*
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index
> 3de2ebe8294aa..f6ce06de41051 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -281,6 +281,13 @@ config SPI_COLDFIRE_QSPI
>           This enables support for the Coldfire QSPI controller in master
>           mode.
> 
> +config SPI_CS42L43
> +       tristate "Cirrus Logic CS42L43 SPI controller"
> +       depends on MFD_CS42L43 && PINCTRL_CS42L43
> +       help
> +         This enables support for the SPI controller inside the Cirrus Logic
> +         CS42L43 audio codec.
> +
>  config SPI_DAVINCI
>         tristate "Texas Instruments DaVinci/DA8x/OMAP-L/AM1x SoC SPI
> controller"
>         depends on ARCH_DAVINCI || ARCH_KEYSTONE || COMPILE_TEST diff --
> git a/drivers/spi/Makefile b/drivers/spi/Makefile index
> 28c4817a8a74a..49937ea0d73d0 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -40,6 +40,7 @@ obj-$(CONFIG_SPI_CADENCE_QUADSPI)     += spi-
> cadence-quadspi.o
>  obj-$(CONFIG_SPI_CADENCE_XSPI)         += spi-cadence-xspi.o
>  obj-$(CONFIG_SPI_CLPS711X)             += spi-clps711x.o
>  obj-$(CONFIG_SPI_COLDFIRE_QSPI)                += spi-coldfire-qspi.o
> +obj-$(CONFIG_SPI_CS42L43)              += spi-cs42l43.o
>  obj-$(CONFIG_SPI_DAVINCI)              += spi-davinci.o
>  obj-$(CONFIG_SPI_DLN2)                 += spi-dln2.o
>  obj-$(CONFIG_SPI_DESIGNWARE)           += spi-dw.o
> diff --git a/drivers/spi/spi-cs42l43.c b/drivers/spi/spi-cs42l43.c new file mode
> 100644 index 0000000000000..5f86f4feb22c8
> --- /dev/null
> +++ b/drivers/spi/spi-cs42l43.c
> @@ -0,0 +1,279 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// CS42L43 SPI Controller Driver
> +//
> +// Copyright (C) 2022-2023 Cirrus Logic, Inc. and
> +//                         Cirrus Logic International Semiconductor Ltd.
> +
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/mfd/cs42l43.h>
> +#include <linux/mfd/cs42l43-regs.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/spi/spi.h>
> +#include <linux/units.h>
> +
> +#define CS42L43_FIFO_SIZE              16
> +#define CS42L43_SPI_ROOT_HZ            (4 * HZ_PER_MHZ)
> +#define CS42L43_SPI_MAX_LENGTH         65532
> +
> +enum cs42l43_spi_cmd {
> +       CS42L43_WRITE,
> +       CS42L43_READ
> +};
> +
> +struct cs42l43_spi {
> +       struct device *dev;
> +       struct regmap *regmap;
> +       struct spi_controller *ctlr;
> +};
> +
> +static unsigned int cs42l43_clock_divs[16] = {
> +       2, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 };
> +
> +static int cs42l43_spi_tx(struct regmap *regmap, const u8 *buf,
> +unsigned int len) {
> +       const u8 *end = buf + len;
> +       u32 val;
> +       int ret;
> +
> +       while (buf < end) {
> +               const u8 *block = min(buf + CS42L43_FIFO_SIZE, end);
> +
> +               for (; buf < block - (sizeof(u32) - 1); buf += sizeof(u32))
> +                       regmap_write(regmap, CS42L43_TX_DATA, *(const
> + u32 *)buf);
> +
> +               if (buf < block) {
> +                       unsigned int residue = end - buf;
> +
> +                       memcpy(&val, buf, residue);
> +                       regmap_write(regmap, CS42L43_TX_DATA, val);
> +                       buf += residue;
> +               }
> +
> +               regmap_write(regmap, CS42L43_TRAN_CONFIG8,
> + CS42L43_SPI_TX_DONE_MASK);
> +
> +               ret = regmap_read_poll_timeout(regmap, CS42L43_TRAN_STATUS1,
> +                                              val, (val & CS42L43_SPI_TX_REQUEST_MASK),
> +                                              1000, 5000);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int cs42l43_spi_rx(struct regmap *regmap, u8 *buf, unsigned int
> +len) {
> +       u8 *end = buf + len;
> +       u32 val;
> +       int ret;
> +
> +       while (buf < end) {
> +               const u8 *block = min(buf + CS42L43_FIFO_SIZE, end);
> +
> +               ret = regmap_read_poll_timeout(regmap, CS42L43_TRAN_STATUS1,
> +                                              val, (val & CS42L43_SPI_RX_REQUEST_MASK),
> +                                              1000, 5000);
> +               if (ret)
> +                       return ret;
> +
> +               for (; buf < block - (sizeof(u32) - 1); buf += sizeof(u32)) {
> +                       ret = regmap_read(regmap, CS42L43_RX_DATA, (u32 *)buf);
> +                       if (ret)
> +                               return ret;
> +               }
> +
> +               if (buf < block) {
> +                       unsigned int residue = end - buf;
> +
> +                       ret = regmap_read(regmap, CS42L43_RX_DATA, &val);
> +                       if (ret)
> +                               return ret;
> +
> +                       memcpy(buf, &val, residue);
> +                       buf += residue;
> +               }
> +
> +               regmap_write(regmap, CS42L43_TRAN_CONFIG8,
> CS42L43_SPI_RX_DONE_MASK);
> +       }
> +
> +       return 0;
> +}
> +
> +static int cs42l43_transfer_one(struct spi_controller *ctlr, struct spi_device
> *spi,
> +                               struct spi_transfer *tfr) {
> +       struct cs42l43_spi *priv = spi_controller_get_devdata(spi->controller);
> +       int i, ret = -EINVAL;
> +
> +       for (i = 0; i < ARRAY_SIZE(cs42l43_clock_divs); i++) {
> +               if (CS42L43_SPI_ROOT_HZ / cs42l43_clock_divs[i] <= tfr->speed_hz)
> +                       break;
> +       }
> +
> +       if (i == ARRAY_SIZE(cs42l43_clock_divs))
> +               return -EINVAL;
> +
> +       regmap_write(priv->regmap, CS42L43_SPI_CLK_CONFIG1, i);
> +
> +       if (tfr->tx_buf) {
> +               regmap_write(priv->regmap, CS42L43_TRAN_CONFIG3,
> CS42L43_WRITE);
> +               regmap_write(priv->regmap, CS42L43_TRAN_CONFIG4, tfr->len - 1);
> +       } else if (tfr->rx_buf) {
> +               regmap_write(priv->regmap, CS42L43_TRAN_CONFIG3,
> CS42L43_READ);
> +               regmap_write(priv->regmap, CS42L43_TRAN_CONFIG5, tfr->len - 1);
> +       }
> +
> +       regmap_write(priv->regmap, CS42L43_TRAN_CONFIG1,
> + CS42L43_SPI_START_MASK);
> +
> +       if (tfr->tx_buf)
> +               ret = cs42l43_spi_tx(priv->regmap, (const u8 *)tfr->tx_buf, tfr->len);
> +       else if (tfr->rx_buf)
> +               ret = cs42l43_spi_rx(priv->regmap, (u8 *)tfr->rx_buf,
> + tfr->len);
> +
> +       return ret;
> +}
> +
> +static void cs42l43_set_cs(struct spi_device *spi, bool is_high) {
> +       struct cs42l43_spi *priv =
> +spi_controller_get_devdata(spi->controller);
> +
> +       if (spi->chip_select == 0)

New set/get APIs for accessing spi->chip_select were introduced by
https://github.com/torvalds/linux/commit/303feb3cc06ac0665d0ee9c1414941200e60e8a3
please use these APIs instead of accessing spi->chip_select directly.

> +               regmap_write(priv->regmap, CS42L43_SPI_CONFIG2,
> +!is_high); }
> +
> +static int cs42l43_prepare_message(struct spi_controller *ctlr, struct
> +spi_message *msg) {
> +       struct cs42l43_spi *priv = spi_controller_get_devdata(ctlr);
> +       struct spi_device *spi = msg->spi;
> +       unsigned int spi_config1 = 0;
> +
> +       /* select another internal CS, which doesn't exist, so CS 0 is not used */
> +       if (spi->cs_gpiod)

Same here for spi->cs_gpio

Regards,
Amit
> +               spi_config1 |= 1 << CS42L43_SPI_SS_SEL_SHIFT;
> +       if (spi->mode & SPI_CPOL)
> +               spi_config1 |= CS42L43_SPI_CPOL_MASK;
> +       if (spi->mode & SPI_CPHA)
> +               spi_config1 |= CS42L43_SPI_CPHA_MASK;
> +       if (spi->mode & SPI_3WIRE)
> +               spi_config1 |= CS42L43_SPI_THREE_WIRE_MASK;
> +
> +       regmap_write(priv->regmap, CS42L43_SPI_CONFIG1, spi_config1);
> +
> +       return 0;
> +}
> +
> +static int cs42l43_prepare_transfer_hardware(struct spi_controller
> +*ctlr) {
> +       struct cs42l43_spi *priv = spi_controller_get_devdata(ctlr);
> +       int ret;
> +
> +       ret = regmap_write(priv->regmap, CS42L43_BLOCK_EN2,
> CS42L43_SPI_MSTR_EN_MASK);
> +       if (ret)
> +               dev_err(priv->dev, "Failed to enable SPI controller:
> + %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static int cs42l43_unprepare_transfer_hardware(struct spi_controller
> +*ctlr) {
> +       struct cs42l43_spi *priv = spi_controller_get_devdata(ctlr);
> +       int ret;
> +
> +       ret = regmap_write(priv->regmap, CS42L43_BLOCK_EN2, 0);
> +       if (ret)
> +               dev_err(priv->dev, "Failed to disable SPI controller:
> + %d\n", ret);
> +
> +       return ret;
> +}
> +
> +static size_t cs42l43_spi_max_length(struct spi_device *spi) {
> +       return CS42L43_SPI_MAX_LENGTH;
> +}
> +
> +static int cs42l43_spi_probe(struct platform_device *pdev) {
> +       struct cs42l43 *cs42l43 = dev_get_drvdata(pdev->dev.parent);
> +       struct cs42l43_spi *priv;
> +       struct fwnode_handle *fwnode = dev_fwnode(cs42l43->dev);
> +       int ret;
> +
> +       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       priv->ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*priv->ctlr));
> +       if (!priv->ctlr)
> +               return -ENOMEM;
> +
> +       spi_controller_set_devdata(priv->ctlr, priv);
> +
> +       priv->dev = &pdev->dev;
> +       priv->regmap = cs42l43->regmap;
> +
> +       priv->ctlr->prepare_message = cs42l43_prepare_message;
> +       priv->ctlr->prepare_transfer_hardware =
> cs42l43_prepare_transfer_hardware;
> +       priv->ctlr->unprepare_transfer_hardware =
> cs42l43_unprepare_transfer_hardware;
> +       priv->ctlr->transfer_one = cs42l43_transfer_one;
> +       priv->ctlr->set_cs = cs42l43_set_cs;
> +       priv->ctlr->max_transfer_size = cs42l43_spi_max_length;
> +
> +       if (is_of_node(fwnode))
> +               fwnode = fwnode_get_named_child_node(fwnode, "spi");
> +
> +       device_set_node(&priv->ctlr->dev, fwnode);
> +
> +       priv->ctlr->mode_bits = SPI_3WIRE | SPI_MODE_X_MASK;
> +       priv->ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;
> +       priv->ctlr->bits_per_word_mask = SPI_BPW_MASK(8) |
> SPI_BPW_MASK(16) |
> +                                        SPI_BPW_MASK(32);
> +       priv->ctlr->min_speed_hz = CS42L43_SPI_ROOT_HZ /
> +                                  cs42l43_clock_divs[ARRAY_SIZE(cs42l43_clock_divs) - 1];
> +       priv->ctlr->max_speed_hz = CS42L43_SPI_ROOT_HZ /
> cs42l43_clock_divs[0];
> +       priv->ctlr->use_gpio_descriptors = true;
> +       priv->ctlr->auto_runtime_pm = true;
> +
> +       devm_pm_runtime_enable(priv->dev);
> +       pm_runtime_idle(priv->dev);
> +
> +       regmap_write(priv->regmap, CS42L43_TRAN_CONFIG6,
> CS42L43_FIFO_SIZE - 1);
> +       regmap_write(priv->regmap, CS42L43_TRAN_CONFIG7,
> + CS42L43_FIFO_SIZE - 1);
> +
> +       // Disable Watchdog timer and enable stall
> +       regmap_write(priv->regmap, CS42L43_SPI_CONFIG3, 0);
> +       regmap_write(priv->regmap, CS42L43_SPI_CONFIG4,
> + CS42L43_SPI_STALL_ENA_MASK);
> +
> +       ret = devm_spi_register_controller(priv->dev, priv->ctlr);
> +       if (ret) {
> +               pm_runtime_disable(priv->dev);
> +               dev_err(priv->dev, "Failed to register SPI controller: %d\n", ret);
> +       }
> +
> +       return ret;
> +}
> +
> +static const struct platform_device_id cs42l43_spi_id_table[] = {
> +       { "cs42l43-spi", },
> +       {}
> +};
> +MODULE_DEVICE_TABLE(platform, cs42l43_spi_id_table);
> +
> +static struct platform_driver cs42l43_spi_driver = {
> +       .driver = {
> +               .name   = "cs42l43-spi",
> +       },
> +       .probe          = cs42l43_spi_probe,
> +       .id_table       = cs42l43_spi_id_table,
> +};
> +module_platform_driver(cs42l43_spi_driver);
> +
> +MODULE_DESCRIPTION("CS42L43 SPI Driver"); MODULE_AUTHOR("Lucas
> Tanure
> +<tanureal@xxxxxxxxxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Maciej Strozek <mstrozek@xxxxxxxxxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 2.30.2