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20#include <linux/device.h>
21#include <linux/io.h>
22#include <linux/module.h>
23#include <linux/serial_8250.h>
24#include <linux/serial_reg.h>
25#include <linux/platform_device.h>
26#include <linux/clk.h>
27#include <linux/slab.h>
28
29#include "8250.h"
30
31#define UART_DLL_EM 9
32#define UART_DLM_EM 10
33
34struct serial8250_em_priv {
35 struct clk *sclk;
36 int line;
37};
38
39static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
40{
41 switch (offset) {
42 case UART_TX:
43 writeb(value, p->membase);
44 break;
45 case UART_FCR:
46 case UART_LCR:
47 case UART_MCR:
48 case UART_SCR:
49 writel(value, p->membase + ((offset + 1) << 2));
50 break;
51 case UART_IER:
52 value &= 0x0f;
53
54 case UART_DLL_EM:
55 case UART_DLM_EM:
56 writel(value, p->membase + (offset << 2));
57 }
58}
59
60static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
61{
62 switch (offset) {
63 case UART_RX:
64 return readb(p->membase);
65 case UART_MCR:
66 case UART_LSR:
67 case UART_MSR:
68 case UART_SCR:
69 return readl(p->membase + ((offset + 1) << 2));
70 case UART_IER:
71 case UART_IIR:
72 case UART_DLL_EM:
73 case UART_DLM_EM:
74 return readl(p->membase + (offset << 2));
75 }
76 return 0;
77}
78
79static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
80{
81 return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
82}
83
84static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
85{
86 serial_out(up, UART_DLL_EM, value & 0xff);
87 serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
88}
89
90static int serial8250_em_probe(struct platform_device *pdev)
91{
92 struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
93 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
94 struct serial8250_em_priv *priv;
95 struct uart_8250_port up;
96 int ret;
97
98 if (!regs || !irq) {
99 dev_err(&pdev->dev, "missing registers or irq\n");
100 return -EINVAL;
101 }
102
103 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
104 if (!priv)
105 return -ENOMEM;
106
107 priv->sclk = devm_clk_get(&pdev->dev, "sclk");
108 if (IS_ERR(priv->sclk)) {
109 dev_err(&pdev->dev, "unable to get clock\n");
110 return PTR_ERR(priv->sclk);
111 }
112
113 memset(&up, 0, sizeof(up));
114 up.port.mapbase = regs->start;
115 up.port.irq = irq->start;
116 up.port.type = PORT_UNKNOWN;
117 up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
118 up.port.dev = &pdev->dev;
119 up.port.private_data = priv;
120
121 clk_prepare_enable(priv->sclk);
122 up.port.uartclk = clk_get_rate(priv->sclk);
123
124 up.port.iotype = UPIO_MEM32;
125 up.port.serial_in = serial8250_em_serial_in;
126 up.port.serial_out = serial8250_em_serial_out;
127 up.dl_read = serial8250_em_serial_dl_read;
128 up.dl_write = serial8250_em_serial_dl_write;
129
130 ret = serial8250_register_8250_port(&up);
131 if (ret < 0) {
132 dev_err(&pdev->dev, "unable to register 8250 port\n");
133 clk_disable_unprepare(priv->sclk);
134 return ret;
135 }
136
137 priv->line = ret;
138 platform_set_drvdata(pdev, priv);
139 return 0;
140}
141
142static int serial8250_em_remove(struct platform_device *pdev)
143{
144 struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
145
146 serial8250_unregister_port(priv->line);
147 clk_disable_unprepare(priv->sclk);
148 return 0;
149}
150
151static const struct of_device_id serial8250_em_dt_ids[] = {
152 { .compatible = "renesas,em-uart", },
153 {},
154};
155MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
156
157static struct platform_driver serial8250_em_platform_driver = {
158 .driver = {
159 .name = "serial8250-em",
160 .of_match_table = serial8250_em_dt_ids,
161 },
162 .probe = serial8250_em_probe,
163 .remove = serial8250_em_remove,
164};
165
166module_platform_driver(serial8250_em_platform_driver);
167
168MODULE_AUTHOR("Magnus Damm");
169MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
170MODULE_LICENSE("GPL v2");
171
