serial: mxs: Add MXS AUART driver
Add trivial driver for the MXS AUART IP. This is the other UART IP
present in i.MX23 and i.MX28, used to drive the non-DUART ports.
Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index f4767c8..a1e0899 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -966,6 +966,14 @@
Driver works in FIFO mode.
Multiple baudrates supported.
+config MXS_AUART_SERIAL
+ bool "MXS AUART"
+ depends on DM_SERIAL
+ help
+ Support for Freescale i.MX23 / i.MX28 AUART or Application UART IP.
+ This IP is present in the aforementioned SoCs, however this is not
+ the IP used to drive the Debug UART port, for that see PL01X_SERIAL .
+
config OCTEON_SERIAL_BOOTCMD
bool "MIPS Octeon PCI remote bootcmd input"
depends on ARCH_OCTEON
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 01fef3f..403ab1d 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -46,6 +46,7 @@
obj-$(CONFIG_BCM283X_PL011_SERIAL) += serial_bcm283x_pl011.o
obj-$(CONFIG_MSM_SERIAL) += serial_msm.o
obj-$(CONFIG_MSM_GENI_SERIAL) += serial_msm_geni.o
+obj-$(CONFIG_MXS_AUART_SERIAL) += serial_mxs.o
obj-$(CONFIG_MVEBU_A3700_UART) += serial_mvebu_a3700.o
obj-$(CONFIG_MPC8XX_CONS) += serial_mpc8xx.o
obj-$(CONFIG_NULLDEV_SERIAL) += serial_nulldev.o
diff --git a/drivers/serial/serial_mxs.c b/drivers/serial/serial_mxs.c
new file mode 100644
index 0000000..3659948
--- /dev/null
+++ b/drivers/serial/serial_mxs.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Marek Vasut <marex@denx.de>
+ */
+#include <common.h>
+#include <dm.h>
+#include <malloc.h>
+#include <serial.h>
+#include <wait_bit.h>
+
+#define SET_REG 0x4
+#define CLR_REG 0x8
+
+#define AUART_CTRL0 0x00
+#define AUART_CTRL1 0x10
+#define AUART_CTRL2 0x20
+#define AUART_LINECTRL 0x30
+#define AUART_INTR 0x50
+#define AUART_DATA 0x60
+#define AUART_STAT 0x70
+
+#define AUART_CTRL0_SFTRST BIT(31)
+#define AUART_CTRL0_CLKGATE BIT(30)
+
+#define AUART_CTRL2_UARTEN BIT(0)
+
+#define AUART_LINECTRL_BAUD_DIVINT(v) (((v) & 0xffff) << 16)
+#define AUART_LINECTRL_BAUD_DIVFRAC(v) (((v) & 0x3f) << 8)
+#define AUART_LINECTRL_WLEN(v) ((((v) - 5) & 0x3) << 5)
+
+#define AUART_STAT_TXFE BIT(27)
+#define AUART_STAT_TXFF BIT(25)
+#define AUART_STAT_RXFE BIT(24)
+
+#define AUART_CLK 24000000
+
+struct mxs_auart_uart_priv {
+ void __iomem *base;
+};
+
+static int mxs_auart_uart_setbrg(struct udevice *dev, int baudrate)
+{
+ struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
+ u32 div;
+
+ writel(AUART_CTRL0_CLKGATE, priv->base + AUART_CTRL0 + CLR_REG);
+ writel(AUART_CTRL0_SFTRST, priv->base + AUART_CTRL0 + CLR_REG);
+
+ writel(AUART_CTRL2_UARTEN, priv->base + AUART_CTRL2 + SET_REG);
+
+ writel(0, priv->base + AUART_INTR);
+
+ div = DIV_ROUND_CLOSEST(AUART_CLK * 32, baudrate);
+
+ /* Disable FIFO, baudrate, 8N1. */
+ writel(AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F) |
+ AUART_LINECTRL_BAUD_DIVINT(div >> 6) |
+ AUART_LINECTRL_WLEN(8),
+ priv->base + AUART_LINECTRL);
+
+ return 0;
+}
+
+static int mxs_auart_uart_pending(struct udevice *dev, bool input)
+{
+ struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
+ u32 stat = readl(priv->base + AUART_STAT);
+
+ if (input)
+ return !(stat & AUART_STAT_RXFE);
+
+ return !!(stat & AUART_STAT_TXFE);
+}
+
+static int mxs_auart_uart_putc(struct udevice *dev, const char ch)
+{
+ struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
+ u32 stat = readl(priv->base + AUART_STAT);
+
+ if (stat & AUART_STAT_TXFF)
+ return -EAGAIN;
+
+ writel(ch, priv->base + AUART_DATA);
+
+ return 0;
+}
+
+static int mxs_auart_uart_getc(struct udevice *dev)
+{
+ struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
+
+ if (!mxs_auart_uart_pending(dev, true))
+ return -EAGAIN;
+
+ return readl(priv->base + AUART_DATA) & 0xff;
+}
+
+static int mxs_auart_uart_probe(struct udevice *dev)
+{
+ struct mxs_auart_uart_priv *priv = dev_get_priv(dev);
+
+ priv->base = dev_read_addr_ptr(dev);
+ if (!priv->base)
+ return -EINVAL;
+
+ return mxs_auart_uart_setbrg(dev, CONFIG_BAUDRATE);
+}
+
+static const struct dm_serial_ops mxs_auart_uart_ops = {
+ .putc = mxs_auart_uart_putc,
+ .pending = mxs_auart_uart_pending,
+ .getc = mxs_auart_uart_getc,
+ .setbrg = mxs_auart_uart_setbrg,
+};
+
+static const struct udevice_id mxs_auart_uart_ids[] = {
+ { .compatible = "fsl,imx23-auart", },
+ { .compatible = "fsl,imx28-auart", },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(mxs_auart_serial) = {
+ .name = "mxs-auart",
+ .id = UCLASS_SERIAL,
+ .of_match = mxs_auart_uart_ids,
+ .probe = mxs_auart_uart_probe,
+ .ops = &mxs_auart_uart_ops,
+ .priv_auto = sizeof(struct mxs_auart_uart_priv),
+};