1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS 4 * Copyright: (C) 2013 Sergei Ianovich <ynvich@gmail.com> 5 * 6 * replaces drivers/serial/pxa.c by Nicolas Pitre 7 * Created: Feb 20, 2003 8 * Copyright: (C) 2003 Monta Vista Software, Inc. 9 * 10 * Based on drivers/serial/8250.c by Russell King. 11 */ 12 13 #include <linux/device.h> 14 #include <linux/init.h> 15 #include <linux/io.h> 16 #include <linux/module.h> 17 #include <linux/serial_8250.h> 18 #include <linux/serial_core.h> 19 #include <linux/serial_reg.h> 20 #include <linux/of.h> 21 #include <linux/of_platform.h> 22 #include <linux/platform_device.h> 23 #include <linux/slab.h> 24 #include <linux/clk.h> 25 #include <linux/pm_runtime.h> 26 27 #include "8250.h" 28 29 struct pxa8250_data { 30 int line; 31 struct clk *clk; 32 }; 33 34 static int __maybe_unused serial_pxa_suspend(struct device *dev) 35 { 36 struct pxa8250_data *data = dev_get_drvdata(dev); 37 38 serial8250_suspend_port(data->line); 39 40 return 0; 41 } 42 43 static int __maybe_unused serial_pxa_resume(struct device *dev) 44 { 45 struct pxa8250_data *data = dev_get_drvdata(dev); 46 47 serial8250_resume_port(data->line); 48 49 return 0; 50 } 51 52 static const struct dev_pm_ops serial_pxa_pm_ops = { 53 SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume) 54 }; 55 56 static const struct of_device_id serial_pxa_dt_ids[] = { 57 { .compatible = "mrvl,pxa-uart", }, 58 { .compatible = "mrvl,mmp-uart", }, 59 {} 60 }; 61 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids); 62 63 /* Uart divisor latch write */ 64 static void serial_pxa_dl_write(struct uart_8250_port *up, int value) 65 { 66 unsigned int dll; 67 68 serial_out(up, UART_DLL, value & 0xff); 69 /* 70 * work around Erratum #74 according to Marvel(R) PXA270M Processor 71 * Specification Update (April 19, 2010) 72 */ 73 dll = serial_in(up, UART_DLL); 74 WARN_ON(dll != (value & 0xff)); 75 76 serial_out(up, UART_DLM, value >> 8 & 0xff); 77 } 78 79 80 static void serial_pxa_pm(struct uart_port *port, unsigned int state, 81 unsigned int oldstate) 82 { 83 struct pxa8250_data *data = port->private_data; 84 85 if (!state) 86 clk_prepare_enable(data->clk); 87 else 88 clk_disable_unprepare(data->clk); 89 } 90 91 static int serial_pxa_probe(struct platform_device *pdev) 92 { 93 struct uart_8250_port uart = {}; 94 struct pxa8250_data *data; 95 struct resource *mmres; 96 int irq, ret; 97 98 irq = platform_get_irq(pdev, 0); 99 if (irq < 0) 100 return irq; 101 102 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); 103 if (!mmres) 104 return -ENODEV; 105 106 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 107 if (!data) 108 return -ENOMEM; 109 110 data->clk = devm_clk_get(&pdev->dev, NULL); 111 if (IS_ERR(data->clk)) 112 return PTR_ERR(data->clk); 113 114 ret = clk_prepare(data->clk); 115 if (ret) 116 return ret; 117 118 ret = of_alias_get_id(pdev->dev.of_node, "serial"); 119 if (ret >= 0) 120 uart.port.line = ret; 121 122 uart.port.type = PORT_XSCALE; 123 uart.port.iotype = UPIO_MEM32; 124 uart.port.mapbase = mmres->start; 125 uart.port.regshift = 2; 126 uart.port.irq = irq; 127 uart.port.fifosize = 64; 128 uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE; 129 uart.port.dev = &pdev->dev; 130 uart.port.uartclk = clk_get_rate(data->clk); 131 uart.port.pm = serial_pxa_pm; 132 uart.port.private_data = data; 133 uart.dl_write = serial_pxa_dl_write; 134 135 ret = serial8250_register_8250_port(&uart); 136 if (ret < 0) 137 goto err_clk; 138 139 data->line = ret; 140 141 platform_set_drvdata(pdev, data); 142 143 return 0; 144 145 err_clk: 146 clk_unprepare(data->clk); 147 return ret; 148 } 149 150 static int serial_pxa_remove(struct platform_device *pdev) 151 { 152 struct pxa8250_data *data = platform_get_drvdata(pdev); 153 154 serial8250_unregister_port(data->line); 155 156 clk_unprepare(data->clk); 157 158 return 0; 159 } 160 161 static struct platform_driver serial_pxa_driver = { 162 .probe = serial_pxa_probe, 163 .remove = serial_pxa_remove, 164 165 .driver = { 166 .name = "pxa2xx-uart", 167 .pm = &serial_pxa_pm_ops, 168 .of_match_table = serial_pxa_dt_ids, 169 }, 170 }; 171 172 module_platform_driver(serial_pxa_driver); 173 174 #ifdef CONFIG_SERIAL_8250_CONSOLE 175 static int __init early_serial_pxa_setup(struct earlycon_device *device, 176 const char *options) 177 { 178 struct uart_port *port = &device->port; 179 180 if (!(device->port.membase || device->port.iobase)) 181 return -ENODEV; 182 183 port->regshift = 2; 184 return early_serial8250_setup(device, NULL); 185 } 186 OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup); 187 #endif 188 189 MODULE_AUTHOR("Sergei Ianovich"); 190 MODULE_LICENSE("GPL"); 191 MODULE_ALIAS("platform:pxa2xx-uart"); 192