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1// SPDX-License-Identifier: GPL-2.0+2/*3 * drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS4 * Copyright: (C) 2013 Sergei Ianovich <ynvich@gmail.com>5 *6 * replaces drivers/serial/pxa.c by Nicolas Pitre7 * Created: Feb 20, 20038 * 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 28struct pxa8250_data {29 int line;30 struct clk *clk;31};32 33static 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 42static 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 51static const struct dev_pm_ops serial_pxa_pm_ops = {52 SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)53};54 55static const struct of_device_id serial_pxa_dt_ids[] = {56 { .compatible = "mrvl,pxa-uart", },57 { .compatible = "mrvl,mmp-uart", },58 {}59};60MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);61 62/* Uart divisor latch write */63static 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 Processor70 * 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 79static 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 else87 clk_disable_unprepare(data->clk);88}89 90static 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 ret;96 97 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);98 if (!mmres)99 return -ENODEV;100 101 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);102 if (!data)103 return -ENOMEM;104 105 data->clk = devm_clk_get(&pdev->dev, NULL);106 if (IS_ERR(data->clk))107 return PTR_ERR(data->clk);108 109 ret = clk_prepare(data->clk);110 if (ret)111 return ret;112 113 uart.port.type = PORT_XSCALE;114 uart.port.mapbase = mmres->start;115 uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;116 uart.port.dev = &pdev->dev;117 uart.port.uartclk = clk_get_rate(data->clk);118 uart.port.pm = serial_pxa_pm;119 uart.port.private_data = data;120 121 ret = uart_read_port_properties(&uart.port);122 if (ret)123 return ret;124 125 uart.port.iotype = UPIO_MEM32;126 uart.port.regshift = 2;127 uart.port.fifosize = 64;128 uart.tx_loadsz = 32;129 uart.dl_write = serial_pxa_dl_write;130 131 ret = serial8250_register_8250_port(&uart);132 if (ret < 0)133 goto err_clk;134 135 data->line = ret;136 137 platform_set_drvdata(pdev, data);138 139 return 0;140 141 err_clk:142 clk_unprepare(data->clk);143 return ret;144}145 146static void serial_pxa_remove(struct platform_device *pdev)147{148 struct pxa8250_data *data = platform_get_drvdata(pdev);149 150 serial8250_unregister_port(data->line);151 152 clk_unprepare(data->clk);153}154 155static struct platform_driver serial_pxa_driver = {156 .probe = serial_pxa_probe,157 .remove_new = 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 166module_platform_driver(serial_pxa_driver);167 168MODULE_AUTHOR("Sergei Ianovich");169MODULE_DESCRIPTION("driver for PXA on-board UARTS");170MODULE_LICENSE("GPL");171MODULE_ALIAS("platform:pxa2xx-uart");172