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