drivers/net/wan/slic_ds26522.c

   1 /*
   2  * drivers/net/wan/slic_ds26522.c
   3  *
   4  * Copyright (C) 2016 Freescale Semiconductor, Inc.
   5  *
   6  * Author:Zhao Qiang<qiang.zhao@nxp.com>
   7  *
   8  * This program is free software; you can redistribute  it and/or modify it
   9  * under  the terms of  the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the  License, or (at your
  11  * option) any later version.
  12  */
  13
  14 #include <linux/bitrev.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/kernel.h>
  18 #include <linux/sched.h>
  19 #include <linux/kthread.h>
  20 #include <linux/spi/spi.h>
  21 #include <linux/wait.h>
  22 #include <linux/param.h>
  23 #include <linux/delay.h>
  24 #include <linux/of.h>
  25 #include <linux/of_address.h>
  26 #include <linux/io.h>
  27 #include "slic_ds26522.h"
  28
  29 #define DRV_NAME "ds26522"
  30
  31 #define SLIC_TRANS_LEN 1
  32 #define SLIC_TWO_LEN 2
  33 #define SLIC_THREE_LEN 3
  34
  35 static struct spi_device *g_spi;
  36
  37 MODULE_LICENSE("GPL");
  38 MODULE_AUTHOR("Zhao Qiang<B45475@freescale.com>");
  39
  40 /* the read/write format of address is
  41  * w/r|A13|A12|A11|A10|A9|A8|A7|A6|A5|A4|A3|A2|A1|A0|x
  42  */
  43 static void slic_write(struct spi_device *spi, u16 addr,
  44                        u8 data)
  45 {
  46         u8 temp[3];
  47
  48         addr = bitrev16(addr) >> 1;
  49         data = bitrev8(data);
  50         temp[0] = (u8)((addr >> 8) & 0x7f);
  51         temp[1] = (u8)(addr & 0xfe);
  52         temp[2] = data;
  53
  54         /* write spi addr and value */
  55         spi_write(spi, &temp[0], SLIC_THREE_LEN);
  56 }
  57
  58 static u8 slic_read(struct spi_device *spi, u16 addr)
  59 {
  60         u8 temp[2];
  61         u8 data;
  62
  63         addr = bitrev16(addr) >> 1;
  64         temp[0] = (u8)(((addr >> 8) & 0x7f) | 0x80);
  65         temp[1] = (u8)(addr & 0xfe);
  66
  67         spi_write_then_read(spi, &temp[0], SLIC_TWO_LEN, &data,
  68                             SLIC_TRANS_LEN);
  69
  70         data = bitrev8(data);
  71         return data;
  72 }
  73
  74 static bool get_slic_product_code(struct spi_device *spi)
  75 {
  76         u8 device_id;
  77
  78         device_id = slic_read(spi, DS26522_IDR_ADDR);
  79         if ((device_id & 0xf8) == 0x68)
  80                 return true;
  81         else
  82                 return false;
  83 }
  84
  85 static void ds26522_e1_spec_config(struct spi_device *spi)
  86 {
  87         /* Receive E1 Mode, Framer Disabled */
  88         slic_write(spi, DS26522_RMMR_ADDR, DS26522_RMMR_E1);
  89
  90         /* Transmit E1 Mode, Framer Disable */
  91         slic_write(spi, DS26522_TMMR_ADDR, DS26522_TMMR_E1);
  92
  93         /* Receive E1 Mode Framer Enable */
  94         slic_write(spi, DS26522_RMMR_ADDR,
  95                    slic_read(spi, DS26522_RMMR_ADDR) | DS26522_RMMR_FRM_EN);
  96
  97         /* Transmit E1 Mode Framer Enable */
  98         slic_write(spi, DS26522_TMMR_ADDR,
  99                    slic_read(spi, DS26522_TMMR_ADDR) | DS26522_TMMR_FRM_EN);
 100
 101         /* RCR1, receive E1 B8zs & ESF */
 102         slic_write(spi, DS26522_RCR1_ADDR,
 103                    DS26522_RCR1_E1_HDB3 | DS26522_RCR1_E1_CCS);
 104
 105         /* RSYSCLK=2.048MHz, RSYNC-Output */
 106         slic_write(spi, DS26522_RIOCR_ADDR,
 107                    DS26522_RIOCR_2048KHZ | DS26522_RIOCR_RSIO_OUT);
 108
 109         /* TCR1 Transmit E1 b8zs */
 110         slic_write(spi, DS26522_TCR1_ADDR, DS26522_TCR1_TB8ZS);
 111
 112         /* TSYSCLK=2.048MHz, TSYNC-Output */
 113         slic_write(spi, DS26522_TIOCR_ADDR,
 114                    DS26522_TIOCR_2048KHZ | DS26522_TIOCR_TSIO_OUT);
 115
 116         /* Set E1TAF */
 117         slic_write(spi, DS26522_E1TAF_ADDR, DS26522_E1TAF_DEFAULT);
 118
 119         /* Set E1TNAF register */
 120         slic_write(spi, DS26522_E1TNAF_ADDR, DS26522_E1TNAF_DEFAULT);
 121
 122         /* Receive E1 Mode Framer Enable & init Done */
 123         slic_write(spi, DS26522_RMMR_ADDR, slic_read(spi, DS26522_RMMR_ADDR) |
 124                    DS26522_RMMR_INIT_DONE);
 125
 126         /* Transmit E1 Mode Framer Enable & init Done */
 127         slic_write(spi, DS26522_TMMR_ADDR, slic_read(spi, DS26522_TMMR_ADDR) |
 128                    DS26522_TMMR_INIT_DONE);
 129
 130         /* Configure LIU E1 mode */
 131         slic_write(spi, DS26522_LTRCR_ADDR, DS26522_LTRCR_E1);
 132
 133         /* E1 Mode default 75 ohm w/Transmit Impedance Matlinking */
 134         slic_write(spi, DS26522_LTITSR_ADDR,
 135                    DS26522_LTITSR_TLIS_75OHM | DS26522_LTITSR_LBOS_75OHM);
 136
 137         /* E1 Mode default 75 ohm Long Haul w/Receive Impedance Matlinking */
 138         slic_write(spi, DS26522_LRISMR_ADDR,
 139                    DS26522_LRISMR_75OHM | DS26522_LRISMR_MAX);
 140
 141         /* Enable Transmit output */
 142         slic_write(spi, DS26522_LMCR_ADDR, DS26522_LMCR_TE);
 143 }
 144
 145 static int slic_ds26522_init_configure(struct spi_device *spi)
 146 {
 147         u16 addr;
 148
 149         /* set clock */
 150         slic_write(spi, DS26522_GTCCR_ADDR, DS26522_GTCCR_BPREFSEL_REFCLKIN |
 151                         DS26522_GTCCR_BFREQSEL_2048KHZ |
 152                         DS26522_GTCCR_FREQSEL_2048KHZ);
 153         slic_write(spi, DS26522_GTCR2_ADDR, DS26522_GTCR2_TSSYNCOUT);
 154         slic_write(spi, DS26522_GFCR_ADDR, DS26522_GFCR_BPCLK_2048KHZ);
 155
 156         /* set gtcr */
 157         slic_write(spi, DS26522_GTCR1_ADDR, DS26522_GTCR1);
 158
 159         /* Global LIU Software Reset Register */
 160         slic_write(spi, DS26522_GLSRR_ADDR, DS26522_GLSRR_RESET);
 161
 162         /* Global Framer and BERT Software Reset Register */
 163         slic_write(spi, DS26522_GFSRR_ADDR, DS26522_GFSRR_RESET);
 164
 165         usleep_range(100, 120);
 166
 167         slic_write(spi, DS26522_GLSRR_ADDR, DS26522_GLSRR_NORMAL);
 168         slic_write(spi, DS26522_GFSRR_ADDR, DS26522_GFSRR_NORMAL);
 169
 170         /* Perform RX/TX SRESET,Reset receiver */
 171         slic_write(spi, DS26522_RMMR_ADDR, DS26522_RMMR_SFTRST);
 172
 173         /* Reset tranceiver */
 174         slic_write(spi, DS26522_TMMR_ADDR, DS26522_TMMR_SFTRST);
 175
 176         usleep_range(100, 120);
 177
 178         /* Zero all Framer Registers */
 179         for (addr = DS26522_RF_ADDR_START; addr <= DS26522_RF_ADDR_END;
 180              addr++)
 181                 slic_write(spi, addr, 0);
 182
 183         for (addr = DS26522_TF_ADDR_START; addr <= DS26522_TF_ADDR_END;
 184              addr++)
 185                 slic_write(spi, addr, 0);
 186
 187         for (addr = DS26522_LIU_ADDR_START; addr <= DS26522_LIU_ADDR_END;
 188              addr++)
 189                 slic_write(spi, addr, 0);
 190
 191         for (addr = DS26522_BERT_ADDR_START; addr <= DS26522_BERT_ADDR_END;
 192              addr++)
 193                 slic_write(spi, addr, 0);
 194
 195         /* setup ds26522 for E1 specification */
 196         ds26522_e1_spec_config(spi);
 197
 198         slic_write(spi, DS26522_GTCR1_ADDR, 0x00);
 199
 200         return 0;
 201 }
 202
 203 static int slic_ds26522_remove(struct spi_device *spi)
 204 {
 205         pr_info("DS26522 module uninstalled\n");
 206         return 0;
 207 }
 208
 209 static int slic_ds26522_probe(struct spi_device *spi)
 210 {
 211         int ret = 0;
 212
 213         g_spi = spi;
 214         spi->bits_per_word = 8;
 215
 216         if (!get_slic_product_code(spi))
 217                 return ret;
 218
 219         ret = slic_ds26522_init_configure(spi);
 220         if (ret == 0)
 221                 pr_info("DS26522 cs%d configured\n", spi->chip_select);
 222
 223         return ret;
 224 }
 225
 226 static const struct spi_device_id slic_ds26522_id[] = {
 227         { .name = "ds26522" },
 228         { /* sentinel */ },
 229 };
 230 MODULE_DEVICE_TABLE(spi, slic_ds26522_id);
 231
 232 static const struct of_device_id slic_ds26522_match[] = {
 233         {
 234          .compatible = "maxim,ds26522",
 235          },
 236         {},
 237 };
 238 MODULE_DEVICE_TABLE(of, slic_ds26522_match);
 239
 240 static struct spi_driver slic_ds26522_driver = {
 241         .driver = {
 242                    .name = "ds26522",
 243                    .bus = &spi_bus_type,
 244                    .of_match_table = slic_ds26522_match,
 245                    },
 246         .probe = slic_ds26522_probe,
 247         .remove = slic_ds26522_remove,
 248         .id_table = slic_ds26522_id,
 249 };
 250
 251 module_spi_driver(slic_ds26522_driver);