diff options
Diffstat (limited to 'drivers/spi/spi-cs42l43.c')
| -rw-r--r-- | drivers/spi/spi-cs42l43.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/drivers/spi/spi-cs42l43.c b/drivers/spi/spi-cs42l43.c new file mode 100644 index 0000000000..d239fc5a49 --- /dev/null +++ b/drivers/spi/spi-cs42l43.c @@ -0,0 +1,283 @@ +// 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/bits.h> +#include <linux/bitfield.h> +#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 (40 * 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 const unsigned int cs42l43_clock_divs[] = { + 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 = 0; + int ret; + + while (buf < end) { + const u8 *block = min(buf + CS42L43_FIFO_SIZE, end); + + while (buf < block) { + const u8 *word = min(buf + sizeof(u32), block); + int pad = (buf + sizeof(u32)) - word; + + while (buf < word) { + val >>= BITS_PER_BYTE; + val |= FIELD_PREP(GENMASK(31, 24), *buf); + + buf++; + } + + val >>= pad * BITS_PER_BYTE; + + regmap_write(regmap, CS42L43_TX_DATA, val); + } + + 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) { + 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; + + while (buf < block) { + u8 *word = min(buf + sizeof(u32), block); + + ret = regmap_read(regmap, CS42L43_RX_DATA, &val); + if (ret) + return ret; + + while (buf < word) { + *buf = FIELD_GET(GENMASK(7, 0), val); + + val >>= BITS_PER_BYTE; + buf++; + } + } + + 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_get_chipselect(spi, 0) == 0) + 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_get_csgpiod(spi, 0)) + 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) { + 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@opensource.cirrus.com>"); +MODULE_AUTHOR("Maciej Strozek <mstrozek@opensource.cirrus.com>"); +MODULE_LICENSE("GPL"); |