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-rw-r--r--drivers/mfd/at91-usart.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/mfd/at91-usart.c b/drivers/mfd/at91-usart.c
new file mode 100644
index 000000000..7f08cb60c
--- /dev/null
+++ b/drivers/mfd/at91-usart.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for AT91 USART
+ *
+ * Copyright (C) 2018 Microchip Technology
+ *
+ * Author: Radu Pirea <radu.pirea@microchip.com>
+ *
+ */
+
+#include <dt-bindings/mfd/at91-usart.h>
+
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/of.h>
+#include <linux/property.h>
+
+static const struct mfd_cell at91_usart_spi_subdev =
+ MFD_CELL_NAME("at91_usart_spi");
+
+static const struct mfd_cell at91_usart_serial_subdev =
+ MFD_CELL_NAME("atmel_usart_serial");
+
+static int at91_usart_mode_probe(struct platform_device *pdev)
+{
+ const struct mfd_cell *cell;
+ u32 opmode = AT91_USART_MODE_SERIAL;
+
+ device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
+
+ switch (opmode) {
+ case AT91_USART_MODE_SPI:
+ cell = &at91_usart_spi_subdev;
+ break;
+ case AT91_USART_MODE_SERIAL:
+ cell = &at91_usart_serial_subdev;
+ break;
+ default:
+ dev_err(&pdev->dev, "atmel,usart-mode has an invalid value %u\n",
+ opmode);
+ return -EINVAL;
+ }
+
+ return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, cell, 1,
+ NULL, 0, NULL);
+}
+
+static const struct of_device_id at91_usart_mode_of_match[] = {
+ { .compatible = "atmel,at91rm9200-usart" },
+ { .compatible = "atmel,at91sam9260-usart" },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, at91_usart_mode_of_match);
+
+static struct platform_driver at91_usart_mfd = {
+ .probe = at91_usart_mode_probe,
+ .driver = {
+ .name = "at91_usart_mode",
+ .of_match_table = at91_usart_mode_of_match,
+ },
+};
+
+module_platform_driver(at91_usart_mfd);
+
+MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
+MODULE_DESCRIPTION("AT91 USART MFD driver");
+MODULE_LICENSE("GPL v2");