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20#include <linux/device.h>
21#include <linux/init.h>
22#include <linux/io.h>
23#include <linux/module.h>
24#include <linux/serial_8250.h>
25#include <linux/serial_core.h>
26#include <linux/serial_reg.h>
27#include <linux/platform_device.h>
28#include <linux/clk.h>
29#include <linux/slab.h>
30
31#include "8250.h"
32
33#define UART_DLL_EM 9
34#define UART_DLM_EM 10
35
36struct serial8250_em_priv {
37 struct clk *sclk;
38 int line;
39};
40
41static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
42{
43 switch (offset) {
44 case UART_TX:
45 writeb(value, p->membase);
46 break;
47 case UART_FCR:
48 case UART_LCR:
49 case UART_MCR:
50 case UART_SCR:
51 writel(value, p->membase + ((offset + 1) << 2));
52 break;
53 case UART_IER:
54 value &= 0x0f;
55
56 case UART_DLL_EM:
57 case UART_DLM_EM:
58 writel(value, p->membase + (offset << 2));
59 }
60}
61
62static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
63{
64 switch (offset) {
65 case UART_RX:
66 return readb(p->membase);
67 case UART_MCR:
68 case UART_LSR:
69 case UART_MSR:
70 case UART_SCR:
71 return readl(p->membase + ((offset + 1) << 2));
72 case UART_IER:
73 case UART_IIR:
74 case UART_DLL_EM:
75 case UART_DLM_EM:
76 return readl(p->membase + (offset << 2));
77 }
78 return 0;
79}
80
81static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
82{
83 return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
84}
85
86static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
87{
88 serial_out(up, UART_DLL_EM, value & 0xff);
89 serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
90}
91
92static int serial8250_em_probe(struct platform_device *pdev)
93{
94 struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
95 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
96 struct serial8250_em_priv *priv;
97 struct uart_8250_port up;
98 int ret = -EINVAL;
99
100 if (!regs || !irq) {
101 dev_err(&pdev->dev, "missing registers or irq\n");
102 goto err0;
103 }
104
105 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
106 if (!priv) {
107 dev_err(&pdev->dev, "unable to allocate private data\n");
108 ret = -ENOMEM;
109 goto err0;
110 }
111
112 priv->sclk = clk_get(&pdev->dev, "sclk");
113 if (IS_ERR(priv->sclk)) {
114 dev_err(&pdev->dev, "unable to get clock\n");
115 ret = PTR_ERR(priv->sclk);
116 goto err1;
117 }
118
119 memset(&up, 0, sizeof(up));
120 up.port.mapbase = regs->start;
121 up.port.irq = irq->start;
122 up.port.type = PORT_UNKNOWN;
123 up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
124 up.port.dev = &pdev->dev;
125 up.port.private_data = priv;
126
127 clk_enable(priv->sclk);
128 up.port.uartclk = clk_get_rate(priv->sclk);
129
130 up.port.iotype = UPIO_MEM32;
131 up.port.serial_in = serial8250_em_serial_in;
132 up.port.serial_out = serial8250_em_serial_out;
133 up.dl_read = serial8250_em_serial_dl_read;
134 up.dl_write = serial8250_em_serial_dl_write;
135
136 ret = serial8250_register_8250_port(&up);
137 if (ret < 0) {
138 dev_err(&pdev->dev, "unable to register 8250 port\n");
139 goto err2;
140 }
141
142 priv->line = ret;
143 platform_set_drvdata(pdev, priv);
144 return 0;
145
146 err2:
147 clk_disable(priv->sclk);
148 clk_put(priv->sclk);
149 err1:
150 kfree(priv);
151 err0:
152 return ret;
153}
154
155static int serial8250_em_remove(struct platform_device *pdev)
156{
157 struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
158
159 serial8250_unregister_port(priv->line);
160 clk_disable(priv->sclk);
161 clk_put(priv->sclk);
162 kfree(priv);
163 return 0;
164}
165
166static const struct of_device_id serial8250_em_dt_ids[] = {
167 { .compatible = "renesas,em-uart", },
168 {},
169};
170MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
171
172static struct platform_driver serial8250_em_platform_driver = {
173 .driver = {
174 .name = "serial8250-em",
175 .of_match_table = serial8250_em_dt_ids,
176 .owner = THIS_MODULE,
177 },
178 .probe = serial8250_em_probe,
179 .remove = serial8250_em_remove,
180};
181
182module_platform_driver(serial8250_em_platform_driver);
183
184MODULE_AUTHOR("Magnus Damm");
185MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
186MODULE_LICENSE("GPL v2");
187
