1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
5 * Derived from linux/drivers/tty/serial/bcm63xx_uart.c:
6 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
11 #include <debug_uart.h>
16 #include <asm/types.h>
18 /* UART Control register */
19 #define UART_CTL_REG 0x0
20 #define UART_CTL_RXTIMEOUT_MASK 0x1f
21 #define UART_CTL_RXTIMEOUT_5 0x5
22 #define UART_CTL_RSTRXFIFO_SHIFT 6
23 #define UART_CTL_RSTRXFIFO_MASK (1 << UART_CTL_RSTRXFIFO_SHIFT)
24 #define UART_CTL_RSTTXFIFO_SHIFT 7
25 #define UART_CTL_RSTTXFIFO_MASK (1 << UART_CTL_RSTTXFIFO_SHIFT)
26 #define UART_CTL_STOPBITS_SHIFT 8
27 #define UART_CTL_STOPBITS_MASK (0xf << UART_CTL_STOPBITS_SHIFT)
28 #define UART_CTL_STOPBITS_1 (0x7 << UART_CTL_STOPBITS_SHIFT)
29 #define UART_CTL_BITSPERSYM_SHIFT 12
30 #define UART_CTL_BITSPERSYM_MASK (0x3 << UART_CTL_BITSPERSYM_SHIFT)
31 #define UART_CTL_BITSPERSYM_8 (0x3 << UART_CTL_BITSPERSYM_SHIFT)
32 #define UART_CTL_XMITBRK_SHIFT 14
33 #define UART_CTL_XMITBRK_MASK (1 << UART_CTL_XMITBRK_SHIFT)
34 #define UART_CTL_RSVD_SHIFT 15
35 #define UART_CTL_RSVD_MASK (1 << UART_CTL_RSVD_SHIFT)
36 #define UART_CTL_RXPAREVEN_SHIFT 16
37 #define UART_CTL_RXPAREVEN_MASK (1 << UART_CTL_RXPAREVEN_SHIFT)
38 #define UART_CTL_RXPAREN_SHIFT 17
39 #define UART_CTL_RXPAREN_MASK (1 << UART_CTL_RXPAREN_SHIFT)
40 #define UART_CTL_TXPAREVEN_SHIFT 18
41 #define UART_CTL_TXPAREVEN_MASK (1 << UART_CTL_TXPAREVEN_SHIFT)
42 #define UART_CTL_TXPAREN_SHIFT 19
43 #define UART_CTL_TXPAREN_MASK (1 << UART_CTL_TXPAREN_SHIFT)
44 #define UART_CTL_LOOPBACK_SHIFT 20
45 #define UART_CTL_LOOPBACK_MASK (1 << UART_CTL_LOOPBACK_SHIFT)
46 #define UART_CTL_RXEN_SHIFT 21
47 #define UART_CTL_RXEN_MASK (1 << UART_CTL_RXEN_SHIFT)
48 #define UART_CTL_TXEN_SHIFT 22
49 #define UART_CTL_TXEN_MASK (1 << UART_CTL_TXEN_SHIFT)
50 #define UART_CTL_BRGEN_SHIFT 23
51 #define UART_CTL_BRGEN_MASK (1 << UART_CTL_BRGEN_SHIFT)
53 /* UART Baudword register */
54 #define UART_BAUD_REG 0x4
56 /* UART FIFO Config register */
57 #define UART_FIFO_CFG_REG 0x8
58 #define UART_FIFO_CFG_RX_SHIFT 8
59 #define UART_FIFO_CFG_RX_MASK (0xf << UART_FIFO_CFG_RX_SHIFT)
60 #define UART_FIFO_CFG_RX_4 (0x4 << UART_FIFO_CFG_RX_SHIFT)
61 #define UART_FIFO_CFG_TX_SHIFT 12
62 #define UART_FIFO_CFG_TX_MASK (0xf << UART_FIFO_CFG_TX_SHIFT)
63 #define UART_FIFO_CFG_TX_4 (0x4 << UART_FIFO_CFG_TX_SHIFT)
65 /* UART Interrupt register */
66 #define UART_IR_REG 0x10
67 #define UART_IR_STAT(x) (1 << (x))
68 #define UART_IR_TXEMPTY 5
69 #define UART_IR_RXOVER 7
70 #define UART_IR_RXNOTEMPTY 11
72 /* UART FIFO register */
73 #define UART_FIFO_REG 0x14
74 #define UART_FIFO_VALID_MASK 0xff
75 #define UART_FIFO_FRAMEERR_SHIFT 8
76 #define UART_FIFO_FRAMEERR_MASK (1 << UART_FIFO_FRAMEERR_SHIFT)
77 #define UART_FIFO_PARERR_SHIFT 9
78 #define UART_FIFO_PARERR_MASK (1 << UART_FIFO_PARERR_SHIFT)
79 #define UART_FIFO_BRKDET_SHIFT 10
80 #define UART_FIFO_BRKDET_MASK (1 << UART_FIFO_BRKDET_SHIFT)
81 #define UART_FIFO_ANYERR_MASK (UART_FIFO_FRAMEERR_MASK | \
82 UART_FIFO_PARERR_MASK | \
83 UART_FIFO_BRKDET_MASK)
85 struct bcm6345_serial_priv
{
90 /* enable rx & tx operation on uart */
91 static void bcm6345_serial_enable(void __iomem
*base
)
93 setbits_32(base
+ UART_CTL_REG
, UART_CTL_BRGEN_MASK
|
94 UART_CTL_TXEN_MASK
| UART_CTL_RXEN_MASK
);
97 /* disable rx & tx operation on uart */
98 static void bcm6345_serial_disable(void __iomem
*base
)
100 clrbits_32(base
+ UART_CTL_REG
, UART_CTL_BRGEN_MASK
|
101 UART_CTL_TXEN_MASK
| UART_CTL_RXEN_MASK
);
104 /* clear all unread data in rx fifo and unsent data in tx fifo */
105 static void bcm6345_serial_flush(void __iomem
*base
)
107 /* empty rx and tx fifo */
108 setbits_32(base
+ UART_CTL_REG
, UART_CTL_RSTRXFIFO_MASK
|
109 UART_CTL_RSTTXFIFO_MASK
);
111 /* read any pending char to make sure all irq status are cleared */
112 readl(base
+ UART_FIFO_REG
);
115 static int bcm6345_serial_init(void __iomem
*base
, ulong clk
, u32 baudrate
)
119 /* mask all irq and flush port */
120 bcm6345_serial_disable(base
);
121 bcm6345_serial_flush(base
);
123 /* set uart control config */
124 clrsetbits_32(base
+ UART_CTL_REG
,
125 /* clear rx timeout */
126 UART_CTL_RXTIMEOUT_MASK
|
127 /* clear stop bits */
128 UART_CTL_STOPBITS_MASK
|
129 /* clear bits per symbol */
130 UART_CTL_BITSPERSYM_MASK
|
131 /* clear xmit break */
132 UART_CTL_XMITBRK_MASK
|
133 /* clear reserved bit */
136 UART_CTL_RXPAREN_MASK
|
137 UART_CTL_TXPAREN_MASK
|
138 /* disable loopback */
139 UART_CTL_LOOPBACK_MASK
,
140 /* set timeout to 5 */
141 UART_CTL_RXTIMEOUT_5
|
142 /* set 8 bits/symbol */
143 UART_CTL_BITSPERSYM_8
|
145 UART_CTL_STOPBITS_1
|
146 /* set parity to even */
147 UART_CTL_RXPAREVEN_MASK
|
148 UART_CTL_TXPAREVEN_MASK
);
150 /* set uart fifo config */
151 clrsetbits_32(base
+ UART_FIFO_CFG_REG
,
152 /* clear fifo config */
153 UART_FIFO_CFG_RX_MASK
|
154 UART_FIFO_CFG_TX_MASK
,
155 /* set fifo config to 4 */
160 val
= ((clk
/ baudrate
) >> 4);
164 val
= (val
>> 1) - 1;
165 writel(val
, base
+ UART_BAUD_REG
);
167 /* clear interrupts */
168 writel(0, base
+ UART_IR_REG
);
171 bcm6345_serial_enable(base
);
176 static int bcm6345_serial_pending(struct udevice
*dev
, bool input
)
178 struct bcm6345_serial_priv
*priv
= dev_get_priv(dev
);
179 u32 val
= readl(priv
->base
+ UART_IR_REG
);
182 return !!(val
& UART_IR_STAT(UART_IR_RXNOTEMPTY
));
184 return !(val
& UART_IR_STAT(UART_IR_TXEMPTY
));
187 static int bcm6345_serial_setbrg(struct udevice
*dev
, int baudrate
)
189 struct bcm6345_serial_priv
*priv
= dev_get_priv(dev
);
191 return bcm6345_serial_init(priv
->base
, priv
->uartclk
, baudrate
);
194 static int bcm6345_serial_putc(struct udevice
*dev
, const char ch
)
196 struct bcm6345_serial_priv
*priv
= dev_get_priv(dev
);
199 val
= readl(priv
->base
+ UART_IR_REG
);
200 if (!(val
& UART_IR_STAT(UART_IR_TXEMPTY
)))
203 writel(ch
, priv
->base
+ UART_FIFO_REG
);
208 static int bcm6345_serial_getc(struct udevice
*dev
)
210 struct bcm6345_serial_priv
*priv
= dev_get_priv(dev
);
213 val
= readl(priv
->base
+ UART_IR_REG
);
214 if (val
& UART_IR_STAT(UART_IR_RXOVER
))
215 setbits_32(priv
->base
+ UART_CTL_REG
, UART_CTL_RSTRXFIFO_MASK
);
216 if (!(val
& UART_IR_STAT(UART_IR_RXNOTEMPTY
)))
219 val
= readl(priv
->base
+ UART_FIFO_REG
);
220 if (val
& UART_FIFO_ANYERR_MASK
)
223 return val
& UART_FIFO_VALID_MASK
;
226 static int bcm6345_serial_probe(struct udevice
*dev
)
228 struct bcm6345_serial_priv
*priv
= dev_get_priv(dev
);
233 priv
->base
= dev_remap_addr(dev
);
238 ret
= clk_get_by_index(dev
, 0, &clk
);
241 priv
->uartclk
= clk_get_rate(&clk
);
244 /* initialize serial */
245 return bcm6345_serial_init(priv
->base
, priv
->uartclk
, CONFIG_BAUDRATE
);
248 static const struct dm_serial_ops bcm6345_serial_ops
= {
249 .putc
= bcm6345_serial_putc
,
250 .pending
= bcm6345_serial_pending
,
251 .getc
= bcm6345_serial_getc
,
252 .setbrg
= bcm6345_serial_setbrg
,
255 static const struct udevice_id bcm6345_serial_ids
[] = {
256 { .compatible
= "brcm,bcm6345-uart" },
260 U_BOOT_DRIVER(bcm6345_serial
) = {
261 .name
= "bcm6345-uart",
263 .of_match
= bcm6345_serial_ids
,
264 .probe
= bcm6345_serial_probe
,
265 .priv_auto
= sizeof(struct bcm6345_serial_priv
),
266 .ops
= &bcm6345_serial_ops
,
269 #ifdef CONFIG_DEBUG_UART_BCM6345
270 static inline void _debug_uart_init(void)
272 void __iomem
*base
= (void __iomem
*)CONFIG_VAL(DEBUG_UART_BASE
);
274 bcm6345_serial_init(base
, CONFIG_DEBUG_UART_CLOCK
, CONFIG_BAUDRATE
);
277 static inline void wait_xfered(void __iomem
*base
)
280 u32 val
= readl(base
+ UART_IR_REG
);
281 if (val
& UART_IR_STAT(UART_IR_TXEMPTY
))
286 static inline void _debug_uart_putc(int ch
)
288 void __iomem
*base
= (void __iomem
*)CONFIG_VAL(DEBUG_UART_BASE
);
291 writel(ch
, base
+ UART_FIFO_REG
);