--- /dev/null
+// 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) {
+ 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@opensource.cirrus.com>");
+MODULE_AUTHOR("Maciej Strozek <mstrozek@opensource.cirrus.com>");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-starfive.git / commitdiff