--- /dev/null
+/*
+ * Renesas Emma Mobile 8250 driver
+ *
+ * Copyright (C) 2012 Magnus Damm
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+
+#include "8250.h"
+
+#define UART_DLL_EM 9
+#define UART_DLM_EM 10
+
+struct serial8250_em_priv {
+ struct clk *sclk;
+ int line;
+};
+
+static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
+{
+ switch (offset) {
+ case UART_TX: /* TX @ 0x00 */
+ writeb(value, p->membase);
+ break;
+ case UART_FCR: /* FCR @ 0x0c (+1) */
+ case UART_LCR: /* LCR @ 0x10 (+1) */
+ case UART_MCR: /* MCR @ 0x14 (+1) */
+ case UART_SCR: /* SCR @ 0x20 (+1) */
+ writel(value, p->membase + ((offset + 1) << 2));
+ break;
+ case UART_IER: /* IER @ 0x04 */
+ value &= 0x0f; /* only 4 valid bits - not Xscale */
+ /* fall-through */
+ case UART_DLL_EM: /* DLL @ 0x24 (+9) */
+ case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+ writel(value, p->membase + (offset << 2));
+ }
+}
+
+static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
+{
+ switch (offset) {
+ case UART_RX: /* RX @ 0x00 */
+ return readb(p->membase);
+ case UART_MCR: /* MCR @ 0x14 (+1) */
+ case UART_LSR: /* LSR @ 0x18 (+1) */
+ case UART_MSR: /* MSR @ 0x1c (+1) */
+ case UART_SCR: /* SCR @ 0x20 (+1) */
+ return readl(p->membase + ((offset + 1) << 2));
+ case UART_IER: /* IER @ 0x04 */
+ case UART_IIR: /* IIR @ 0x08 */
+ case UART_DLL_EM: /* DLL @ 0x24 (+9) */
+ case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+ return readl(p->membase + (offset << 2));
+ }
+ return 0;
+}
+
+static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
+{
+ return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
+}
+
+static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
+{
+ serial_out(up, UART_DLL_EM, value & 0xff);
+ serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
+}
+
+static int serial8250_em_probe(struct platform_device *pdev)
+{
+ struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ struct serial8250_em_priv *priv;
+ struct uart_8250_port up;
+ int ret;
+
+ if (!regs || !irq) {
+ dev_err(&pdev->dev, "missing registers or irq\n");
+ return -EINVAL;
+ }
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->sclk = devm_clk_get(&pdev->dev, "sclk");
+ if (IS_ERR(priv->sclk)) {
+ dev_err(&pdev->dev, "unable to get clock\n");
+ return PTR_ERR(priv->sclk);
+ }
+
+ memset(&up, 0, sizeof(up));
+ up.port.mapbase = regs->start;
+ up.port.irq = irq->start;
+ up.port.type = PORT_UNKNOWN;
+ up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
+ up.port.dev = &pdev->dev;
+ up.port.private_data = priv;
+
+ clk_prepare_enable(priv->sclk);
+ up.port.uartclk = clk_get_rate(priv->sclk);
+
+ up.port.iotype = UPIO_MEM32;
+ up.port.serial_in = serial8250_em_serial_in;
+ up.port.serial_out = serial8250_em_serial_out;
+ up.dl_read = serial8250_em_serial_dl_read;
+ up.dl_write = serial8250_em_serial_dl_write;
+
+ ret = serial8250_register_8250_port(&up);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "unable to register 8250 port\n");
+ clk_disable_unprepare(priv->sclk);
+ return ret;
+ }
+
+ priv->line = ret;
+ platform_set_drvdata(pdev, priv);
+ return 0;
+}
+
+static int serial8250_em_remove(struct platform_device *pdev)
+{
+ struct serial8250_em_priv *priv = platform_get_drvdata(pdev);
+
+ serial8250_unregister_port(priv->line);
+ clk_disable_unprepare(priv->sclk);
+ return 0;
+}
+
+static const struct of_device_id serial8250_em_dt_ids[] = {
+ { .compatible = "renesas,em-uart", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, serial8250_em_dt_ids);
+
+static struct platform_driver serial8250_em_platform_driver = {
+ .driver = {
+ .name = "serial8250-em",
+ .of_match_table = serial8250_em_dt_ids,
+ },
+ .probe = serial8250_em_probe,
+ .remove = serial8250_em_remove,
+};
+
+module_platform_driver(serial8250_em_platform_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile 8250 Driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff