Maxim/driver: Add driver for maxim ds26522

Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 255 insertions, 0 deletions

diff --git a/drivers/net/wan/slic_ds26522.c b/drivers/net/wan/slic_ds26522.c
new file mode 100644
index 000000000000..d06a887a2352
--- /dev/null
+++ b/drivers/net/wan/slic_ds26522.c
@@ -0,0 +1,255 @@
+/*
+ * drivers/net/wan/slic_ds26522.c
+ *
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ *
+ * Author:Zhao Qiang<qiang.zhao@nxp.com>
+ *
+ * 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, or (at your
+ * option) any later version.
+ */
+
+#include <linux/bitrev.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/kthread.h>
+#include <linux/spi/spi.h>
+#include <linux/wait.h>
+#include <linux/param.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include "slic_ds26522.h"
+
+#define DRV_NAME "ds26522"
+
+#define SLIC_TRANS_LEN 1
+#define SLIC_TWO_LEN 2
+#define SLIC_THREE_LEN 3
+
+static struct spi_device *g_spi;
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Zhao Qiang<B45475@freescale.com>");
+
+/* the read/write format of address is
+ * w/r|A13|A12|A11|A10|A9|A8|A7|A6|A5|A4|A3|A2|A1|A0|x
+ */
+static void slic_write(struct spi_device *spi, u16 addr,
+		       u8 data)
+{
+	u8 temp[3];
+
+	addr = bitrev16(addr) >> 1;
+	data = bitrev8(data);
+	temp[0] = (u8)((addr >> 8) & 0x7f);
+	temp[1] = (u8)(addr & 0xfe);
+	temp[2] = data;
+
+	/* write spi addr and value */
+	spi_write(spi, &temp[0], SLIC_THREE_LEN);
+}
+
+static u8 slic_read(struct spi_device *spi, u16 addr)
+{
+	u8 temp[2];
+	u8 data;
+
+	addr = bitrev16(addr) >> 1;
+	temp[0] = (u8)(((addr >> 8) & 0x7f) | 0x80);
+	temp[1] = (u8)(addr & 0xfe);
+
+	spi_write_then_read(spi, &temp[0], SLIC_TWO_LEN, &data,
+			    SLIC_TRANS_LEN);
+
+	data = bitrev8(data);
+	return data;
+}
+
+static bool get_slic_product_code(struct spi_device *spi)
+{
+	u8 device_id;
+
+	device_id = slic_read(spi, DS26522_IDR_ADDR);
+	if ((device_id & 0xf8) == 0x68)
+		return true;
+	else
+		return false;
+}
+
+static void ds26522_e1_spec_config(struct spi_device *spi)
+{
+	/* Receive E1 Mode, Framer Disabled */
+	slic_write(spi, DS26522_RMMR_ADDR, DS26522_RMMR_E1);
+
+	/* Transmit E1 Mode, Framer Disable */
+	slic_write(spi, DS26522_TMMR_ADDR, DS26522_TMMR_E1);
+
+	/* Receive E1 Mode Framer Enable */
+	slic_write(spi, DS26522_RMMR_ADDR,
+		   slic_read(spi, DS26522_RMMR_ADDR) | DS26522_RMMR_FRM_EN);
+
+	/* Transmit E1 Mode Framer Enable */
+	slic_write(spi, DS26522_TMMR_ADDR,
+		   slic_read(spi, DS26522_TMMR_ADDR) | DS26522_TMMR_FRM_EN);
+
+	/* RCR1, receive E1 B8zs & ESF */
+	slic_write(spi, DS26522_RCR1_ADDR,
+		   DS26522_RCR1_E1_HDB3 | DS26522_RCR1_E1_CCS);
+
+	/* RSYSCLK=2.048MHz, RSYNC-Output */
+	slic_write(spi, DS26522_RIOCR_ADDR,
+		   DS26522_RIOCR_2048KHZ | DS26522_RIOCR_RSIO_OUT);
+
+	/* TCR1 Transmit E1 b8zs */
+	slic_write(spi, DS26522_TCR1_ADDR, DS26522_TCR1_TB8ZS);
+
+	/* TSYSCLK=2.048MHz, TSYNC-Output */
+	slic_write(spi, DS26522_TIOCR_ADDR,
+		   DS26522_TIOCR_2048KHZ | DS26522_TIOCR_TSIO_OUT);
+
+	/* Set E1TAF */
+	slic_write(spi, DS26522_E1TAF_ADDR, DS26522_E1TAF_DEFAULT);
+
+	/* Set E1TNAF register */
+	slic_write(spi, DS26522_E1TNAF_ADDR, DS26522_E1TNAF_DEFAULT);
+
+	/* Receive E1 Mode Framer Enable & init Done */
+	slic_write(spi, DS26522_RMMR_ADDR, slic_read(spi, DS26522_RMMR_ADDR) |
+		   DS26522_RMMR_INIT_DONE);
+
+	/* Transmit E1 Mode Framer Enable & init Done */
+	slic_write(spi, DS26522_TMMR_ADDR, slic_read(spi, DS26522_TMMR_ADDR) |
+		   DS26522_TMMR_INIT_DONE);
+
+	/* Configure LIU E1 mode */
+	slic_write(spi, DS26522_LTRCR_ADDR, DS26522_LTRCR_E1);
+
+	/* E1 Mode default 75 ohm w/Transmit Impedance Matlinking */
+	slic_write(spi, DS26522_LTITSR_ADDR,
+		   DS26522_LTITSR_TLIS_75OHM | DS26522_LTITSR_LBOS_75OHM);
+
+	/* E1 Mode default 75 ohm Long Haul w/Receive Impedance Matlinking */
+	slic_write(spi, DS26522_LRISMR_ADDR,
+		   DS26522_LRISMR_75OHM | DS26522_LRISMR_MAX);
+
+	/* Enable Transmit output */
+	slic_write(spi, DS26522_LMCR_ADDR, DS26522_LMCR_TE);
+}
+
+static int slic_ds26522_init_configure(struct spi_device *spi)
+{
+	u16 addr;
+
+	/* set clock */
+	slic_write(spi, DS26522_GTCCR_ADDR, DS26522_GTCCR_BPREFSEL_REFCLKIN |
+			DS26522_GTCCR_BFREQSEL_2048KHZ |
+			DS26522_GTCCR_FREQSEL_2048KHZ);
+	slic_write(spi, DS26522_GTCR2_ADDR, DS26522_GTCR2_TSSYNCOUT);
+	slic_write(spi, DS26522_GFCR_ADDR, DS26522_GFCR_BPCLK_2048KHZ);
+
+	/* set gtcr */
+	slic_write(spi, DS26522_GTCR1_ADDR, DS26522_GTCR1);
+
+	/* Global LIU Software Reset Register */
+	slic_write(spi, DS26522_GLSRR_ADDR, DS26522_GLSRR_RESET);
+
+	/* Global Framer and BERT Software Reset Register */
+	slic_write(spi, DS26522_GFSRR_ADDR, DS26522_GFSRR_RESET);
+
+	usleep_range(100, 120);
+
+	slic_write(spi, DS26522_GLSRR_ADDR, DS26522_GLSRR_NORMAL);
+	slic_write(spi, DS26522_GFSRR_ADDR, DS26522_GFSRR_NORMAL);
+
+	/* Perform RX/TX SRESET,Reset receiver */
+	slic_write(spi, DS26522_RMMR_ADDR, DS26522_RMMR_SFTRST);
+
+	/* Reset tranceiver */
+	slic_write(spi, DS26522_TMMR_ADDR, DS26522_TMMR_SFTRST);
+
+	usleep_range(100, 120);
+
+	/* Zero all Framer Registers */
+	for (addr = DS26522_RF_ADDR_START; addr <= DS26522_RF_ADDR_END;
+	     addr++)
+		slic_write(spi, addr, 0);
+
+	for (addr = DS26522_TF_ADDR_START; addr <= DS26522_TF_ADDR_END;
+	     addr++)
+		slic_write(spi, addr, 0);
+
+	for (addr = DS26522_LIU_ADDR_START; addr <= DS26522_LIU_ADDR_END;
+	     addr++)
+		slic_write(spi, addr, 0);
+
+	for (addr = DS26522_BERT_ADDR_START; addr <= DS26522_BERT_ADDR_END;
+	     addr++)
+		slic_write(spi, addr, 0);
+
+	/* setup ds26522 for E1 specification */
+	ds26522_e1_spec_config(spi);
+
+	slic_write(spi, DS26522_GTCR1_ADDR, 0x00);
+
+	return 0;
+}
+
+static int slic_ds26522_remove(struct spi_device *spi)
+{
+	pr_info("DS26522 module uninstalled\n");
+	return 0;
+}
+
+static int slic_ds26522_probe(struct spi_device *spi)
+{
+	int ret = 0;
+
+	g_spi = spi;
+	spi->bits_per_word = 8;
+
+	if (!get_slic_product_code(spi))
+		return ret;
+
+	ret = slic_ds26522_init_configure(spi);
+	if (ret == 0)
+		pr_info("DS26522 cs%d configurated\n", spi->chip_select);
+
+	return ret;
+}
+
+static const struct of_device_id slic_ds26522_match[] = {
+	{
+	 .compatible = "maxim,ds26522",
+	 },
+	{},
+};
+
+static struct spi_driver slic_ds26522_driver = {
+	.driver = {
+		   .name = "ds26522",
+		   .bus = &spi_bus_type,
+		   .owner = THIS_MODULE,
+		   .of_match_table = slic_ds26522_match,
+		   },
+	.probe = slic_ds26522_probe,
+	.remove = slic_ds26522_remove,
+};
+
+static int __init slic_ds26522_init(void)
+{
+	return spi_register_driver(&slic_ds26522_driver);
+}
+
+static void __exit slic_ds26522_exit(void)
+{
+	spi_unregister_driver(&slic_ds26522_driver);
+}
+
+module_init(slic_ds26522_init);
+module_exit(slic_ds26522_exit);