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-rw-r--r--drivers/serial/serial_meson.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/serial/serial_meson.c b/drivers/serial/serial_meson.c
new file mode 100644
index 0000000..1b49426
--- /dev/null
+++ b/drivers/serial/serial_meson.c
@@ -0,0 +1,162 @@
+/*
+ * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <linux/compiler.h>
+#include <serial.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct meson_uart {
+ u32 wfifo;
+ u32 rfifo;
+ u32 control;
+ u32 status;
+ u32 misc;
+};
+
+struct meson_serial_platdata {
+ struct meson_uart *reg;
+};
+
+/* AML_UART_STATUS bits */
+#define AML_UART_PARITY_ERR BIT(16)
+#define AML_UART_FRAME_ERR BIT(17)
+#define AML_UART_TX_FIFO_WERR BIT(18)
+#define AML_UART_RX_EMPTY BIT(20)
+#define AML_UART_TX_FULL BIT(21)
+#define AML_UART_TX_EMPTY BIT(22)
+#define AML_UART_XMIT_BUSY BIT(25)
+#define AML_UART_ERR (AML_UART_PARITY_ERR | \
+ AML_UART_FRAME_ERR | \
+ AML_UART_TX_FIFO_WERR)
+
+/* AML_UART_CONTROL bits */
+#define AML_UART_TX_EN BIT(12)
+#define AML_UART_RX_EN BIT(13)
+#define AML_UART_TX_RST BIT(22)
+#define AML_UART_RX_RST BIT(23)
+#define AML_UART_CLR_ERR BIT(24)
+
+static void meson_serial_init(struct meson_uart *uart)
+{
+ u32 val;
+
+ val = readl(&uart->control);
+ val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
+ writel(val, &uart->control);
+ val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
+ writel(val, &uart->control);
+ val |= (AML_UART_RX_EN | AML_UART_TX_EN);
+ writel(val, &uart->control);
+}
+
+static int meson_serial_probe(struct udevice *dev)
+{
+ struct meson_serial_platdata *plat = dev->platdata;
+ struct meson_uart *const uart = plat->reg;
+
+ meson_serial_init(uart);
+
+ return 0;
+}
+
+static int meson_serial_getc(struct udevice *dev)
+{
+ struct meson_serial_platdata *plat = dev->platdata;
+ struct meson_uart *const uart = plat->reg;
+
+ if (readl(&uart->status) & AML_UART_RX_EMPTY)
+ return -EAGAIN;
+
+ return readl(&uart->rfifo) & 0xff;
+}
+
+static int meson_serial_putc(struct udevice *dev, const char ch)
+{
+ struct meson_serial_platdata *plat = dev->platdata;
+ struct meson_uart *const uart = plat->reg;
+
+ if (readl(&uart->status) & AML_UART_TX_FULL)
+ return -EAGAIN;
+
+ writel(ch, &uart->wfifo);
+
+ return 0;
+}
+
+static int meson_serial_pending(struct udevice *dev, bool input)
+{
+ struct meson_serial_platdata *plat = dev->platdata;
+ struct meson_uart *const uart = plat->reg;
+ uint32_t status = readl(&uart->status);
+
+ if (input)
+ return !(status & AML_UART_RX_EMPTY);
+ else
+ return !(status & AML_UART_TX_FULL);
+}
+
+static int meson_serial_ofdata_to_platdata(struct udevice *dev)
+{
+ struct meson_serial_platdata *plat = dev->platdata;
+ fdt_addr_t addr;
+
+ addr = dev_get_addr(dev);
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ plat->reg = (struct meson_uart *)addr;
+
+ return 0;
+}
+
+static const struct dm_serial_ops meson_serial_ops = {
+ .putc = meson_serial_putc,
+ .pending = meson_serial_pending,
+ .getc = meson_serial_getc,
+};
+
+static const struct udevice_id meson_serial_ids[] = {
+ { .compatible = "amlogic,meson-uart" },
+ { }
+};
+
+U_BOOT_DRIVER(serial_meson) = {
+ .name = "serial_meson",
+ .id = UCLASS_SERIAL,
+ .of_match = meson_serial_ids,
+ .probe = meson_serial_probe,
+ .ops = &meson_serial_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+ .ofdata_to_platdata = meson_serial_ofdata_to_platdata,
+ .platdata_auto_alloc_size = sizeof(struct meson_serial_platdata),
+};
+
+#ifdef CONFIG_DEBUG_UART_MESON
+
+#include <debug_uart.h>
+
+static inline void _debug_uart_init(void)
+{
+}
+
+static inline void _debug_uart_putc(int ch)
+{
+ struct meson_uart *regs = (struct meson_uart *)CONFIG_DEBUG_UART_BASE;
+
+ while (readl(&regs->status) & AML_UART_TX_FULL)
+ ;
+
+ writel(ch, &regs->wfifo);
+}
+
+DEBUG_UART_FUNCS
+
+#endif