1 /* 2 * drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS 3 * Copyright: (C) 2013 Sergei Ianovich <ynvich@gmail.com> 4 * 5 * replaces drivers/serial/pxa.c by Nicolas Pitre 6 * Created: Feb 20, 2003 7 * Copyright: (C) 2003 Monta Vista Software, Inc. 8 * 9 * Based on drivers/serial/8250.c by Russell King. 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 */ 17 18 #include <linux/device.h> 19 #include <linux/init.h> 20 #include <linux/io.h> 21 #include <linux/module.h> 22 #include <linux/serial_8250.h> 23 #include <linux/serial_core.h> 24 #include <linux/serial_reg.h> 25 #include <linux/of.h> 26 #include <linux/of_irq.h> 27 #include <linux/of_platform.h> 28 #include <linux/platform_device.h> 29 #include <linux/slab.h> 30 #include <linux/clk.h> 31 #include <linux/pm_runtime.h> 32 33 #include "8250.h" 34 35 struct pxa8250_data { 36 int line; 37 struct clk *clk; 38 }; 39 40 static int __maybe_unused serial_pxa_suspend(struct device *dev) 41 { 42 struct pxa8250_data *data = dev_get_drvdata(dev); 43 44 serial8250_suspend_port(data->line); 45 46 return 0; 47 } 48 49 static int __maybe_unused serial_pxa_resume(struct device *dev) 50 { 51 struct pxa8250_data *data = dev_get_drvdata(dev); 52 53 serial8250_resume_port(data->line); 54 55 return 0; 56 } 57 58 static const struct dev_pm_ops serial_pxa_pm_ops = { 59 SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume) 60 }; 61 62 static const struct of_device_id serial_pxa_dt_ids[] = { 63 { .compatible = "mrvl,pxa-uart", }, 64 { .compatible = "mrvl,mmp-uart", }, 65 {} 66 }; 67 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids); 68 69 /* Uart divisor latch write */ 70 static void serial_pxa_dl_write(struct uart_8250_port *up, int value) 71 { 72 unsigned int dll; 73 74 serial_out(up, UART_DLL, value & 0xff); 75 /* 76 * work around Erratum #74 according to Marvel(R) PXA270M Processor 77 * Specification Update (April 19, 2010) 78 */ 79 dll = serial_in(up, UART_DLL); 80 WARN_ON(dll != (value & 0xff)); 81 82 serial_out(up, UART_DLM, value >> 8 & 0xff); 83 } 84 85 86 static void serial_pxa_pm(struct uart_port *port, unsigned int state, 87 unsigned int oldstate) 88 { 89 struct pxa8250_data *data = port->private_data; 90 91 if (!state) 92 clk_prepare_enable(data->clk); 93 else 94 clk_disable_unprepare(data->clk); 95 } 96 97 static int serial_pxa_probe(struct platform_device *pdev) 98 { 99 struct uart_8250_port uart = {}; 100 struct pxa8250_data *data; 101 struct resource *mmres, *irqres; 102 int ret; 103 104 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); 105 irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 106 if (!mmres || !irqres) 107 return -ENODEV; 108 109 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 110 if (!data) 111 return -ENOMEM; 112 113 data->clk = devm_clk_get(&pdev->dev, NULL); 114 if (IS_ERR(data->clk)) 115 return PTR_ERR(data->clk); 116 117 ret = clk_prepare(data->clk); 118 if (ret) 119 return ret; 120 121 uart.port.type = PORT_XSCALE; 122 uart.port.iotype = UPIO_MEM32; 123 uart.port.mapbase = mmres->start; 124 uart.port.regshift = 2; 125 uart.port.irq = irqres->start; 126 uart.port.fifosize = 64; 127 uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST; 128 uart.port.dev = &pdev->dev; 129 uart.port.uartclk = clk_get_rate(data->clk); 130 uart.port.pm = serial_pxa_pm; 131 uart.port.private_data = data; 132 uart.dl_write = serial_pxa_dl_write; 133 134 ret = serial8250_register_8250_port(&uart); 135 if (ret < 0) 136 goto err_clk; 137 138 data->line = ret; 139 140 platform_set_drvdata(pdev, data); 141 142 return 0; 143 144 err_clk: 145 clk_unprepare(data->clk); 146 return ret; 147 } 148 149 static int serial_pxa_remove(struct platform_device *pdev) 150 { 151 struct pxa8250_data *data = platform_get_drvdata(pdev); 152 153 serial8250_unregister_port(data->line); 154 155 clk_unprepare(data->clk); 156 157 return 0; 158 } 159 160 static struct platform_driver serial_pxa_driver = { 161 .probe = serial_pxa_probe, 162 .remove = serial_pxa_remove, 163 164 .driver = { 165 .name = "pxa2xx-uart", 166 .pm = &serial_pxa_pm_ops, 167 .of_match_table = serial_pxa_dt_ids, 168 }, 169 }; 170 171 module_platform_driver(serial_pxa_driver); 172 173 #ifdef CONFIG_SERIAL_8250_CONSOLE 174 static int __init early_serial_pxa_setup(struct earlycon_device *device, 175 const char *options) 176 { 177 struct uart_port *port = &device->port; 178 179 if (!(device->port.membase || device->port.iobase)) 180 return -ENODEV; 181 182 port->regshift = 2; 183 return early_serial8250_setup(device, NULL); 184 } 185 OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup); 186 #endif 187 188 MODULE_AUTHOR("Sergei Ianovich"); 189 MODULE_LICENSE("GPL"); 190 MODULE_ALIAS("platform:pxa2xx-uart"); 191