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163 lines
4.1 KiB
163 lines
4.1 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Renesas Emma Mobile 8250 driver |
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* |
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* Copyright (C) 2012 Magnus Damm |
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*/ |
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#include <linux/device.h> |
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#include <linux/io.h> |
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#include <linux/module.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/serial_8250.h> |
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#include <linux/serial_reg.h> |
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#include <linux/platform_device.h> |
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#include <linux/clk.h> |
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#include <linux/slab.h> |
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#include "8250.h" |
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#define UART_DLL_EM 9 |
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#define UART_DLM_EM 10 |
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struct serial8250_em_priv { |
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struct clk *sclk; |
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int line; |
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}; |
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static void serial8250_em_serial_out(struct uart_port *p, int offset, int value) |
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{ |
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switch (offset) { |
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case UART_TX: /* TX @ 0x00 */ |
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writeb(value, p->membase); |
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break; |
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case UART_FCR: /* FCR @ 0x0c (+1) */ |
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case UART_LCR: /* LCR @ 0x10 (+1) */ |
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case UART_MCR: /* MCR @ 0x14 (+1) */ |
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case UART_SCR: /* SCR @ 0x20 (+1) */ |
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writel(value, p->membase + ((offset + 1) << 2)); |
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break; |
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case UART_IER: /* IER @ 0x04 */ |
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value &= 0x0f; /* only 4 valid bits - not Xscale */ |
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fallthrough; |
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case UART_DLL_EM: /* DLL @ 0x24 (+9) */ |
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case UART_DLM_EM: /* DLM @ 0x28 (+9) */ |
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writel(value, p->membase + (offset << 2)); |
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} |
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} |
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static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset) |
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{ |
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switch (offset) { |
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case UART_RX: /* RX @ 0x00 */ |
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return readb(p->membase); |
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case UART_MCR: /* MCR @ 0x14 (+1) */ |
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case UART_LSR: /* LSR @ 0x18 (+1) */ |
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case UART_MSR: /* MSR @ 0x1c (+1) */ |
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case UART_SCR: /* SCR @ 0x20 (+1) */ |
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return readl(p->membase + ((offset + 1) << 2)); |
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case UART_IER: /* IER @ 0x04 */ |
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case UART_IIR: /* IIR @ 0x08 */ |
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case UART_DLL_EM: /* DLL @ 0x24 (+9) */ |
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case UART_DLM_EM: /* DLM @ 0x28 (+9) */ |
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return readl(p->membase + (offset << 2)); |
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} |
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return 0; |
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} |
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static int serial8250_em_serial_dl_read(struct uart_8250_port *up) |
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{ |
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return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8; |
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} |
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static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value) |
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{ |
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serial_out(up, UART_DLL_EM, value & 0xff); |
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serial_out(up, UART_DLM_EM, value >> 8 & 0xff); |
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} |
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static int serial8250_em_probe(struct platform_device *pdev) |
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{ |
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struct serial8250_em_priv *priv; |
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struct uart_8250_port up; |
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struct resource *regs; |
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int irq, ret; |
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irq = platform_get_irq(pdev, 0); |
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if (irq < 0) |
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return irq; |
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regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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if (!regs) { |
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dev_err(&pdev->dev, "missing registers\n"); |
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return -EINVAL; |
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} |
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
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if (!priv) |
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return -ENOMEM; |
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priv->sclk = devm_clk_get(&pdev->dev, "sclk"); |
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if (IS_ERR(priv->sclk)) { |
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dev_err(&pdev->dev, "unable to get clock\n"); |
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return PTR_ERR(priv->sclk); |
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} |
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memset(&up, 0, sizeof(up)); |
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up.port.mapbase = regs->start; |
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up.port.irq = irq; |
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up.port.type = PORT_UNKNOWN; |
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up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP; |
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up.port.dev = &pdev->dev; |
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up.port.private_data = priv; |
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clk_prepare_enable(priv->sclk); |
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up.port.uartclk = clk_get_rate(priv->sclk); |
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up.port.iotype = UPIO_MEM32; |
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up.port.serial_in = serial8250_em_serial_in; |
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up.port.serial_out = serial8250_em_serial_out; |
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up.dl_read = serial8250_em_serial_dl_read; |
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up.dl_write = serial8250_em_serial_dl_write; |
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ret = serial8250_register_8250_port(&up); |
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if (ret < 0) { |
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dev_err(&pdev->dev, "unable to register 8250 port\n"); |
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clk_disable_unprepare(priv->sclk); |
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return ret; |
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} |
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priv->line = ret; |
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platform_set_drvdata(pdev, priv); |
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return 0; |
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} |
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static int serial8250_em_remove(struct platform_device *pdev) |
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{ |
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struct serial8250_em_priv *priv = platform_get_drvdata(pdev); |
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serial8250_unregister_port(priv->line); |
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clk_disable_unprepare(priv->sclk); |
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return 0; |
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} |
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static const struct of_device_id serial8250_em_dt_ids[] = { |
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{ .compatible = "renesas,em-uart", }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids); |
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static struct platform_driver serial8250_em_platform_driver = { |
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.driver = { |
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.name = "serial8250-em", |
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.of_match_table = serial8250_em_dt_ids, |
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}, |
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.probe = serial8250_em_probe, |
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.remove = serial8250_em_remove, |
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}; |
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module_platform_driver(serial8250_em_platform_driver); |
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MODULE_AUTHOR("Magnus Damm"); |
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MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver"); |
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MODULE_LICENSE("GPL v2");
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