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 26 #include "8250.h" 27 28 struct pxa8250_data { 29 int line; 30 struct clk *clk; 31 }; 32 33 static int __maybe_unused serial_pxa_suspend(struct device *dev) 34 { 35 struct pxa8250_data *data = dev_get_drvdata(dev); 36 37 serial8250_suspend_port(data->line); 38 39 return 0; 40 } 41 42 static int __maybe_unused serial_pxa_resume(struct device *dev) 43 { 44 struct pxa8250_data *data = dev_get_drvdata(dev); 45 46 serial8250_resume_port(data->line); 47 48 return 0; 49 } 50 51 static const struct dev_pm_ops serial_pxa_pm_ops = { 52 SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume) 53 }; 54 55 static const struct of_device_id serial_pxa_dt_ids[] = { 56 { .compatible = "mrvl,pxa-uart", }, 57 { .compatible = "mrvl,mmp-uart", }, 58 {} 59 }; 60 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids); 61 62 /* Uart divisor latch write */ 63 static void serial_pxa_dl_write(struct uart_8250_port *up, u32 value) 64 { 65 unsigned int dll; 66 67 serial_out(up, UART_DLL, value & 0xff); 68 /* 69 * work around Erratum #74 according to Marvel(R) PXA270M Processor 70 * Specification Update (April 19, 2010) 71 */ 72 dll = serial_in(up, UART_DLL); 73 WARN_ON(dll != (value & 0xff)); 74 75 serial_out(up, UART_DLM, value >> 8 & 0xff); 76 } 77 78 79 static void serial_pxa_pm(struct uart_port *port, unsigned int state, 80 unsigned int oldstate) 81 { 82 struct pxa8250_data *data = port->private_data; 83 84 if (!state) 85 clk_prepare_enable(data->clk); 86 else 87 clk_disable_unprepare(data->clk); 88 } 89 90 static int serial_pxa_probe(struct platform_device *pdev) 91 { 92 struct uart_8250_port uart = {}; 93 struct pxa8250_data *data; 94 struct resource *mmres; 95 int irq, ret; 96 97 irq = platform_get_irq(pdev, 0); 98 if (irq < 0) 99 return irq; 100 101 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); 102 if (!mmres) 103 return -ENODEV; 104 105 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 106 if (!data) 107 return -ENOMEM; 108 109 data->clk = devm_clk_get(&pdev->dev, NULL); 110 if (IS_ERR(data->clk)) 111 return PTR_ERR(data->clk); 112 113 ret = clk_prepare(data->clk); 114 if (ret) 115 return ret; 116 117 ret = of_alias_get_id(pdev->dev.of_node, "serial"); 118 if (ret >= 0) 119 uart.port.line = 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 = irq; 126 uart.port.fifosize = 64; 127 uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE; 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 OF_EARLYCON_DECLARE(mmp, "mrvl,mmp-uart", early_serial_pxa_setup); 187 #endif 188 189 MODULE_AUTHOR("Sergei Ianovich"); 190 MODULE_LICENSE("GPL"); 191 MODULE_ALIAS("platform:pxa2xx-uart"); 192