1 /*
2 * The setup file for serial related hardware on PMC-Sierra MSP processors.
3 *
4 * Copyright 2005 PMC-Sierra, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 *
11 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
12 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
14 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
15 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
16 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
17 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
18 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
19 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
20 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
21 *
22 * You should have received a copy of the GNU General Public License along
23 * with this program; if not, write to the Free Software Foundation, Inc.,
24 * 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26
27 #include <linux/serial.h>
28 #include <linux/serial_core.h>
29 #include <linux/serial_reg.h>
30 #include <linux/slab.h>
31
32 #include <asm/bootinfo.h>
33 #include <asm/io.h>
34 #include <asm/processor.h>
35 #include <asm/serial.h>
36 #include <linux/serial_8250.h>
37
38 #include <msp_prom.h>
39 #include <msp_int.h>
40 #include <msp_regs.h>
41
42 struct msp_uart_data {
43 int last_lcr;
44 };
45
46 static void msp_serial_out(struct uart_port *p, int offset, int value)
47 {
48 struct msp_uart_data *d = p->private_data;
49
50 if (offset == UART_LCR)
51 d->last_lcr = value;
52
53 offset <<= p->regshift;
54 writeb(value, p->membase + offset);
55 }
56
57 static unsigned int msp_serial_in(struct uart_port *p, int offset)
58 {
59 offset <<= p->regshift;
60
61 return readb(p->membase + offset);
62 }
63
64 static int msp_serial_handle_irq(struct uart_port *p)
65 {
66 struct msp_uart_data *d = p->private_data;
67 unsigned int iir = readb(p->membase + (UART_IIR << p->regshift));
68
69 if (serial8250_handle_irq(p, iir)) {
70 return 1;
71 } else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
72 /*
73 * The DesignWare APB UART has an Busy Detect (0x07) interrupt
74 * meaning an LCR write attempt occurred while the UART was
75 * busy. The interrupt must be cleared by reading the UART
76 * status register (USR) and the LCR re-written.
77 *
78 * Note: MSP reserves 0x20 bytes of address space for the UART
79 * and the USR is mapped in a separate block at an offset of
80 * 0xc0 from the start of the UART.
81 */
82 (void)readb(p->membase + 0xc0);
83 writeb(d->last_lcr, p->membase + (UART_LCR << p->regshift));
84
85 return 1;
86 }
87
88 return 0;
89 }
90
91 void __init msp_serial_setup(void)
92 {
93 char *s;
94 char *endp;
95 struct uart_port up;
96 unsigned int uartclk;
97
98 memset(&up, 0, sizeof(up));
99
100 /* Check if clock was specified in environment */
101 s = prom_getenv("uartfreqhz");
102 if(!(s && *s && (uartclk = simple_strtoul(s, &endp, 10)) && *endp == 0))
103 uartclk = MSP_BASE_BAUD;
104 ppfinit("UART clock set to %d\n", uartclk);
105
106 /* Initialize first serial port */
107 up.mapbase = MSP_UART0_BASE;
108 up.membase = ioremap_nocache(up.mapbase, MSP_UART_REG_LEN);
109 up.irq = MSP_INT_UART0;
110 up.uartclk = uartclk;
111 up.regshift = 2;
112 up.iotype = UPIO_MEM;
113 up.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST;
114 up.type = PORT_16550A;
115 up.line = 0;
116 up.serial_out = msp_serial_out;
117 up.serial_in = msp_serial_in;
118 up.handle_irq = msp_serial_handle_irq;
119 up.private_data = kzalloc(sizeof(struct msp_uart_data), GFP_KERNEL);
120 if (!up.private_data) {
121 pr_err("failed to allocate uart private data\n");
122 return;
123 }
124 if (early_serial_setup(&up)) {
125 kfree(up.private_data);
126 pr_err("Early serial init of port 0 failed\n");
127 }
128
129 /* Initialize the second serial port, if one exists */
130 switch (mips_machtype) {
131 case MACH_MSP4200_EVAL:
132 case MACH_MSP4200_GW:
133 case MACH_MSP4200_FPGA:
134 case MACH_MSP7120_EVAL:
135 case MACH_MSP7120_GW:
136 case MACH_MSP7120_FPGA:
137 /* Enable UART1 on MSP4200 and MSP7120 */
138 *GPIO_CFG2_REG = 0x00002299;
139 break;
140
141 default:
142 return; /* No second serial port, good-bye. */
143 }
144
145 up.mapbase = MSP_UART1_BASE;
146 up.membase = ioremap_nocache(up.mapbase, MSP_UART_REG_LEN);
147 up.irq = MSP_INT_UART1;
148 up.line = 1;
149 up.private_data = (void*)UART1_STATUS_REG;
150 if (early_serial_setup(&up)) {
151 kfree(up.private_data);
152 pr_err("Early serial init of port 1 failed\n");
153 }
154 }