2 * (C) Copyright 2016 Beniamino Galvani <b.galvani@gmail.com>
4 * SPDX-License-Identifier: GPL-2.0+
11 #include <linux/compiler.h>
22 struct meson_serial_platdata {
23 struct meson_uart *reg;
26 /* AML_UART_STATUS bits */
27 #define AML_UART_PARITY_ERR BIT(16)
28 #define AML_UART_FRAME_ERR BIT(17)
29 #define AML_UART_TX_FIFO_WERR BIT(18)
30 #define AML_UART_RX_EMPTY BIT(20)
31 #define AML_UART_TX_FULL BIT(21)
32 #define AML_UART_TX_EMPTY BIT(22)
33 #define AML_UART_XMIT_BUSY BIT(25)
34 #define AML_UART_ERR (AML_UART_PARITY_ERR | \
35 AML_UART_FRAME_ERR | \
36 AML_UART_TX_FIFO_WERR)
38 /* AML_UART_CONTROL bits */
39 #define AML_UART_TX_EN BIT(12)
40 #define AML_UART_RX_EN BIT(13)
41 #define AML_UART_TX_RST BIT(22)
42 #define AML_UART_RX_RST BIT(23)
43 #define AML_UART_CLR_ERR BIT(24)
45 static void meson_serial_init(struct meson_uart *uart)
49 val = readl(&uart->control);
50 val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
51 writel(val, &uart->control);
52 val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
53 writel(val, &uart->control);
54 val |= (AML_UART_RX_EN | AML_UART_TX_EN);
55 writel(val, &uart->control);
58 static int meson_serial_probe(struct udevice *dev)
60 struct meson_serial_platdata *plat = dev->platdata;
61 struct meson_uart *const uart = plat->reg;
63 meson_serial_init(uart);
68 static int meson_serial_getc(struct udevice *dev)
70 struct meson_serial_platdata *plat = dev->platdata;
71 struct meson_uart *const uart = plat->reg;
73 if (readl(&uart->status) & AML_UART_RX_EMPTY)
76 return readl(&uart->rfifo) & 0xff;
79 static int meson_serial_putc(struct udevice *dev, const char ch)
81 struct meson_serial_platdata *plat = dev->platdata;
82 struct meson_uart *const uart = plat->reg;
84 if (readl(&uart->status) & AML_UART_TX_FULL)
87 writel(ch, &uart->wfifo);
92 static int meson_serial_pending(struct udevice *dev, bool input)
94 struct meson_serial_platdata *plat = dev->platdata;
95 struct meson_uart *const uart = plat->reg;
96 uint32_t status = readl(&uart->status);
99 return !(status & AML_UART_RX_EMPTY);
101 return !(status & AML_UART_TX_FULL);
104 static int meson_serial_ofdata_to_platdata(struct udevice *dev)
106 struct meson_serial_platdata *plat = dev->platdata;
109 addr = devfdt_get_addr(dev);
110 if (addr == FDT_ADDR_T_NONE)
113 plat->reg = (struct meson_uart *)addr;
118 static const struct dm_serial_ops meson_serial_ops = {
119 .putc = meson_serial_putc,
120 .pending = meson_serial_pending,
121 .getc = meson_serial_getc,
124 static const struct udevice_id meson_serial_ids[] = {
125 { .compatible = "amlogic,meson-uart" },
126 { .compatible = "amlogic,meson-gx-uart" },
130 U_BOOT_DRIVER(serial_meson) = {
131 .name = "serial_meson",
133 .of_match = meson_serial_ids,
134 .probe = meson_serial_probe,
135 .ops = &meson_serial_ops,
136 .flags = DM_FLAG_PRE_RELOC,
137 .ofdata_to_platdata = meson_serial_ofdata_to_platdata,
138 .platdata_auto_alloc_size = sizeof(struct meson_serial_platdata),
141 #ifdef CONFIG_DEBUG_UART_MESON
143 #include <debug_uart.h>
145 static inline void _debug_uart_init(void)
149 static inline void _debug_uart_putc(int ch)
151 struct meson_uart *regs = (struct meson_uart *)CONFIG_DEBUG_UART_BASE;
153 while (readl(®s->status) & AML_UART_TX_FULL)
156 writel(ch, ®s->wfifo);