1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
From c35aec61e5bb0faafb2847a0d750ebd7345a4b0f Mon Sep 17 00:00:00 2001
From: Yangbo Lu <yangbo.lu@nxp.com>
Date: Wed, 17 Jan 2018 15:40:24 +0800
Subject: [PATCH 28/30] tty: serial: support layerscape
This is an integrated patch for layerscape uart support.
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
drivers/tty/serial/fsl_lpuart.c | 66 ++++++++++++++++++++++++++++-------------
1 file changed, 46 insertions(+), 20 deletions(-)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -231,6 +231,8 @@
#define DEV_NAME "ttyLP"
#define UART_NR 6
+static DECLARE_BITMAP(linemap, UART_NR);
+
struct lpuart_port {
struct uart_port port;
struct clk *clk;
@@ -1349,6 +1351,18 @@ lpuart_set_termios(struct uart_port *por
/* ask the core to calculate the divisor */
baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
+ /*
+ * Need to update the Ring buffer length according to the selected
+ * baud rate and restart Rx DMA path.
+ *
+ * Since timer function acqures sport->port.lock, need to stop before
+ * acquring same lock because otherwise del_timer_sync() can deadlock.
+ */
+ if (old && sport->lpuart_dma_rx_use) {
+ del_timer_sync(&sport->lpuart_timer);
+ lpuart_dma_rx_free(&sport->port);
+ }
+
spin_lock_irqsave(&sport->port.lock, flags);
sport->port.read_status_mask = 0;
@@ -1398,22 +1412,11 @@ lpuart_set_termios(struct uart_port *por
/* restore control register */
writeb(old_cr2, sport->port.membase + UARTCR2);
- /*
- * If new baud rate is set, we will also need to update the Ring buffer
- * length according to the selected baud rate and restart Rx DMA path.
- */
- if (old) {
- if (sport->lpuart_dma_rx_use) {
- del_timer_sync(&sport->lpuart_timer);
- lpuart_dma_rx_free(&sport->port);
- }
-
- if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
- sport->lpuart_dma_rx_use = true;
+ if (old && sport->lpuart_dma_rx_use) {
+ if (!lpuart_start_rx_dma(sport))
rx_dma_timer_init(sport);
- } else {
+ else
sport->lpuart_dma_rx_use = false;
- }
}
spin_unlock_irqrestore(&sport->port.lock, flags);
@@ -1641,6 +1644,13 @@ lpuart_console_write(struct console *co,
{
struct lpuart_port *sport = lpuart_ports[co->index];
unsigned char old_cr2, cr2;
+ unsigned long flags;
+ int locked = 1;
+
+ if (sport->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&sport->port.lock, flags);
+ else
+ spin_lock_irqsave(&sport->port.lock, flags);
/* first save CR2 and then disable interrupts */
cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
@@ -1655,6 +1665,9 @@ lpuart_console_write(struct console *co,
barrier();
writeb(old_cr2, sport->port.membase + UARTCR2);
+
+ if (locked)
+ spin_unlock_irqrestore(&sport->port.lock, flags);
}
static void
@@ -1662,6 +1675,13 @@ lpuart32_console_write(struct console *c
{
struct lpuart_port *sport = lpuart_ports[co->index];
unsigned long old_cr, cr;
+ unsigned long flags;
+ int locked = 1;
+
+ if (sport->port.sysrq || oops_in_progress)
+ locked = spin_trylock_irqsave(&sport->port.lock, flags);
+ else
+ spin_lock_irqsave(&sport->port.lock, flags);
/* first save CR2 and then disable interrupts */
cr = old_cr = lpuart32_read(sport->port.membase + UARTCTRL);
@@ -1676,6 +1696,9 @@ lpuart32_console_write(struct console *c
barrier();
lpuart32_write(old_cr, sport->port.membase + UARTCTRL);
+
+ if (locked)
+ spin_unlock_irqrestore(&sport->port.lock, flags);
}
/*
@@ -1900,13 +1923,13 @@ static int lpuart_probe(struct platform_
ret = of_alias_get_id(np, "serial");
if (ret < 0) {
- dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
- return ret;
- }
- if (ret >= ARRAY_SIZE(lpuart_ports)) {
- dev_err(&pdev->dev, "serial%d out of range\n", ret);
- return -EINVAL;
+ ret = find_first_zero_bit(linemap, UART_NR);
+ if (ret >= UART_NR) {
+ dev_err(&pdev->dev, "port line is full, add device failed\n");
+ return ret;
+ }
}
+ set_bit(ret, linemap);
sport->port.line = ret;
sport->lpuart32 = of_device_is_compatible(np, "fsl,ls1021a-lpuart");
@@ -1988,6 +2011,7 @@ static int lpuart_remove(struct platform
struct lpuart_port *sport = platform_get_drvdata(pdev);
uart_remove_one_port(&lpuart_reg, &sport->port);
+ clear_bit(sport->port.line, linemap);
clk_disable_unprepare(sport->clk);
@@ -2072,12 +2096,10 @@ static int lpuart_resume(struct device *
if (sport->lpuart_dma_rx_use) {
if (sport->port.irq_wake) {
- if (!lpuart_start_rx_dma(sport)) {
- sport->lpuart_dma_rx_use = true;
+ if (!lpuart_start_rx_dma(sport))
rx_dma_timer_init(sport);
- } else {
+ else
sport->lpuart_dma_rx_use = false;
- }
}
}
|
