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Diffstat (limited to 'drivers/mux/adgs1408.c')
-rw-r--r--drivers/mux/adgs1408.c131
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/mux/adgs1408.c b/drivers/mux/adgs1408.c
new file mode 100644
index 000000000000..0f7cf54e3234
--- /dev/null
+++ b/drivers/mux/adgs1408.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ADGS1408/ADGS1409 SPI MUX driver
+ *
+ * Copyright 2018 Analog Devices Inc.
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mux/driver.h>
+#include <linux/of_platform.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+
+#define ADGS1408_SW_DATA (0x01)
+#define ADGS1408_REG_READ(reg) ((reg) | 0x80)
+#define ADGS1408_DISABLE (0x00)
+#define ADGS1408_MUX(state) (((state) << 1) | 1)
+
+enum adgs1408_chip_id {
+ ADGS1408 = 1,
+ ADGS1409,
+};
+
+static int adgs1408_spi_reg_write(struct spi_device *spi,
+ u8 reg_addr, u8 reg_data)
+{
+ u8 tx_buf[2];
+
+ tx_buf[0] = reg_addr;
+ tx_buf[1] = reg_data;
+
+ return spi_write_then_read(spi, tx_buf, sizeof(tx_buf), NULL, 0);
+}
+
+static int adgs1408_set(struct mux_control *mux, int state)
+{
+ struct spi_device *spi = to_spi_device(mux->chip->dev.parent);
+ u8 reg;
+
+ if (state == MUX_IDLE_DISCONNECT)
+ reg = ADGS1408_DISABLE;
+ else
+ reg = ADGS1408_MUX(state);
+
+ return adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, reg);
+}
+
+static const struct mux_control_ops adgs1408_ops = {
+ .set = adgs1408_set,
+};
+
+static int adgs1408_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ enum adgs1408_chip_id chip_id;
+ struct mux_chip *mux_chip;
+ struct mux_control *mux;
+ s32 idle_state;
+ int ret;
+
+ chip_id = (enum adgs1408_chip_id)of_device_get_match_data(dev);
+ if (!chip_id)
+ chip_id = spi_get_device_id(spi)->driver_data;
+
+ mux_chip = devm_mux_chip_alloc(dev, 1, 0);
+ if (IS_ERR(mux_chip))
+ return PTR_ERR(mux_chip);
+
+ mux_chip->ops = &adgs1408_ops;
+
+ ret = adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, ADGS1408_DISABLE);
+ if (ret < 0)
+ return ret;
+
+ ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state);
+ if (ret < 0)
+ idle_state = MUX_IDLE_AS_IS;
+
+ mux = mux_chip->mux;
+
+ if (chip_id == ADGS1408)
+ mux->states = 8;
+ else
+ mux->states = 4;
+
+ switch (idle_state) {
+ case MUX_IDLE_DISCONNECT:
+ case MUX_IDLE_AS_IS:
+ case 0 ... 7:
+ /* adgs1409 supports only 4 states */
+ if (idle_state < mux->states) {
+ mux->idle_state = idle_state;
+ break;
+ }
+ /* fall through */
+ default:
+ dev_err(dev, "invalid idle-state %d\n", idle_state);
+ return -EINVAL;
+ }
+
+ return devm_mux_chip_register(dev, mux_chip);
+}
+
+static const struct spi_device_id adgs1408_spi_id[] = {
+ { "adgs1408", ADGS1408 },
+ { "adgs1409", ADGS1409 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, adgs1408_spi_id);
+
+static const struct of_device_id adgs1408_of_match[] = {
+ { .compatible = "adi,adgs1408", .data = (void *)ADGS1408, },
+ { .compatible = "adi,adgs1409", .data = (void *)ADGS1409, },
+ { }
+};
+MODULE_DEVICE_TABLE(of, adgs1408_of_match);
+
+static struct spi_driver adgs1408_driver = {
+ .driver = {
+ .name = "adgs1408",
+ .of_match_table = of_match_ptr(adgs1408_of_match),
+ },
+ .probe = adgs1408_probe,
+ .id_table = adgs1408_spi_id,
+};
+module_spi_driver(adgs1408_driver);
+
+MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver");
+MODULE_LICENSE("GPL v2");