drivers/net/wan/slic_ds26522.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * drivers/net/wan/slic_ds26522.c
   4  *
   5  * Copyright (C) 2016 Freescale Semiconductor, Inc.
   6  *
   7  * Author:Zhao Qiang<[email protected]>
   8  */
   9
  10 #include <linux/bitrev.h>
  11 #include <linux/module.h>
  12 #include <linux/device.h>
  13 #include <linux/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/kthread.h>
  16 #include <linux/spi/spi.h>
  17 #include <linux/wait.h>
  18 #include <linux/param.h>
  19 #include <linux/delay.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/io.h>
  23 #include "slic_ds26522.h"
  24
  25 #define SLIC_TRANS_LEN 1
  26 #define SLIC_TWO_LEN 2
  27 #define SLIC_THREE_LEN 3
  28
  29 static struct spi_device *g_spi;
  30
  31 MODULE_DESCRIPTION("Slic Maxim DS26522 driver");
  32 MODULE_LICENSE("GPL");
  33 MODULE_AUTHOR("Zhao Qiang<[email protected]>");
  34
  35 /* the read/write format of address is
  36  * w/r|A13|A12|A11|A10|A9|A8|A7|A6|A5|A4|A3|A2|A1|A0|x
  37  */
  38 static void slic_write(struct spi_device *spi, u16 addr,
  39                        u8 data)
  40 {
  41         u8 temp[3];
  42
  43         addr = bitrev16(addr) >> 1;
  44         data = bitrev8(data);
  45         temp[0] = (u8)((addr >> 8) & 0x7f);
  46         temp[1] = (u8)(addr & 0xfe);
  47         temp[2] = data;
  48
  49         /* write spi addr and value */
  50         spi_write(spi, &temp[0], SLIC_THREE_LEN);
  51 }
  52
  53 static u8 slic_read(struct spi_device *spi, u16 addr)
  54 {
  55         u8 temp[2];
  56         u8 data;
  57
  58         addr = bitrev16(addr) >> 1;
  59         temp[0] = (u8)(((addr >> 8) & 0x7f) | 0x80);
  60         temp[1] = (u8)(addr & 0xfe);
  61
  62         spi_write_then_read(spi, &temp[0], SLIC_TWO_LEN, &data,
  63                             SLIC_TRANS_LEN);
  64
  65         data = bitrev8(data);
  66         return data;
  67 }
  68
  69 static bool get_slic_product_code(struct spi_device *spi)
  70 {
  71         u8 device_id;
  72
  73         device_id = slic_read(spi, DS26522_IDR_ADDR);
  74         if ((device_id & 0xf8) == 0x68)
  75                 return true;
  76         else
  77                 return false;
  78 }
  79
  80 static void ds26522_e1_spec_config(struct spi_device *spi)
  81 {
  82         /* Receive E1 Mode, Framer Disabled */
  83         slic_write(spi, DS26522_RMMR_ADDR, DS26522_RMMR_E1);
  84
  85         /* Transmit E1 Mode, Framer Disable */
  86         slic_write(spi, DS26522_TMMR_ADDR, DS26522_TMMR_E1);
  87
  88         /* Receive E1 Mode Framer Enable */
  89         slic_write(spi, DS26522_RMMR_ADDR,
  90                    slic_read(spi, DS26522_RMMR_ADDR) | DS26522_RMMR_FRM_EN);
  91
  92         /* Transmit E1 Mode Framer Enable */
  93         slic_write(spi, DS26522_TMMR_ADDR,
  94                    slic_read(spi, DS26522_TMMR_ADDR) | DS26522_TMMR_FRM_EN);
  95
  96         /* RCR1, receive E1 B8zs & ESF */
  97         slic_write(spi, DS26522_RCR1_ADDR,
  98                    DS26522_RCR1_E1_HDB3 | DS26522_RCR1_E1_CCS);
  99
 100         /* RSYSCLK=2.048MHz, RSYNC-Output */
 101         slic_write(spi, DS26522_RIOCR_ADDR,
 102                    DS26522_RIOCR_2048KHZ | DS26522_RIOCR_RSIO_OUT);
 103
 104         /* TCR1 Transmit E1 b8zs */
 105         slic_write(spi, DS26522_TCR1_ADDR, DS26522_TCR1_TB8ZS);
 106
 107         /* TSYSCLK=2.048MHz, TSYNC-Output */
 108         slic_write(spi, DS26522_TIOCR_ADDR,
 109                    DS26522_TIOCR_2048KHZ | DS26522_TIOCR_TSIO_OUT);
 110
 111         /* Set E1TAF */
 112         slic_write(spi, DS26522_E1TAF_ADDR, DS26522_E1TAF_DEFAULT);
 113
 114         /* Set E1TNAF register */
 115         slic_write(spi, DS26522_E1TNAF_ADDR, DS26522_E1TNAF_DEFAULT);
 116
 117         /* Receive E1 Mode Framer Enable & init Done */
 118         slic_write(spi, DS26522_RMMR_ADDR, slic_read(spi, DS26522_RMMR_ADDR) |
 119                    DS26522_RMMR_INIT_DONE);
 120
 121         /* Transmit E1 Mode Framer Enable & init Done */
 122         slic_write(spi, DS26522_TMMR_ADDR, slic_read(spi, DS26522_TMMR_ADDR) |
 123                    DS26522_TMMR_INIT_DONE);
 124
 125         /* Configure LIU E1 mode */
 126         slic_write(spi, DS26522_LTRCR_ADDR, DS26522_LTRCR_E1);
 127
 128         /* E1 Mode default 75 ohm w/Transmit Impedance Matlinking */
 129         slic_write(spi, DS26522_LTITSR_ADDR,
 130                    DS26522_LTITSR_TLIS_75OHM | DS26522_LTITSR_LBOS_75OHM);
 131
 132         /* E1 Mode default 75 ohm Long Haul w/Receive Impedance Matlinking */
 133         slic_write(spi, DS26522_LRISMR_ADDR,
 134                    DS26522_LRISMR_75OHM | DS26522_LRISMR_MAX);
 135
 136         /* Enable Transmit output */
 137         slic_write(spi, DS26522_LMCR_ADDR, DS26522_LMCR_TE);
 138 }
 139
 140 static int slic_ds26522_init_configure(struct spi_device *spi)
 141 {
 142         u16 addr;
 143
 144         /* set clock */
 145         slic_write(spi, DS26522_GTCCR_ADDR, DS26522_GTCCR_BPREFSEL_REFCLKIN |
 146                         DS26522_GTCCR_BFREQSEL_2048KHZ |
 147                         DS26522_GTCCR_FREQSEL_2048KHZ);
 148         slic_write(spi, DS26522_GTCR2_ADDR, DS26522_GTCR2_TSSYNCOUT);
 149         slic_write(spi, DS26522_GFCR_ADDR, DS26522_GFCR_BPCLK_2048KHZ);
 150
 151         /* set gtcr */
 152         slic_write(spi, DS26522_GTCR1_ADDR, DS26522_GTCR1);
 153
 154         /* Global LIU Software Reset Register */
 155         slic_write(spi, DS26522_GLSRR_ADDR, DS26522_GLSRR_RESET);
 156
 157         /* Global Framer and BERT Software Reset Register */
 158         slic_write(spi, DS26522_GFSRR_ADDR, DS26522_GFSRR_RESET);
 159
 160         usleep_range(100, 120);
 161
 162         slic_write(spi, DS26522_GLSRR_ADDR, DS26522_GLSRR_NORMAL);
 163         slic_write(spi, DS26522_GFSRR_ADDR, DS26522_GFSRR_NORMAL);
 164
 165         /* Perform RX/TX SRESET,Reset receiver */
 166         slic_write(spi, DS26522_RMMR_ADDR, DS26522_RMMR_SFTRST);
 167
 168         /* Reset tranceiver */
 169         slic_write(spi, DS26522_TMMR_ADDR, DS26522_TMMR_SFTRST);
 170
 171         usleep_range(100, 120);
 172
 173         /* Zero all Framer Registers */
 174         for (addr = DS26522_RF_ADDR_START; addr <= DS26522_RF_ADDR_END;
 175              addr++)
 176                 slic_write(spi, addr, 0);
 177
 178         for (addr = DS26522_TF_ADDR_START; addr <= DS26522_TF_ADDR_END;
 179              addr++)
 180                 slic_write(spi, addr, 0);
 181
 182         for (addr = DS26522_LIU_ADDR_START; addr <= DS26522_LIU_ADDR_END;
 183              addr++)
 184                 slic_write(spi, addr, 0);
 185
 186         for (addr = DS26522_BERT_ADDR_START; addr <= DS26522_BERT_ADDR_END;
 187              addr++)
 188                 slic_write(spi, addr, 0);
 189
 190         /* setup ds26522 for E1 specification */
 191         ds26522_e1_spec_config(spi);
 192
 193         slic_write(spi, DS26522_GTCR1_ADDR, 0x00);
 194
 195         return 0;
 196 }
 197
 198 static void slic_ds26522_remove(struct spi_device *spi)
 199 {
 200         pr_info("DS26522 module uninstalled\n");
 201 }
 202
 203 static int slic_ds26522_probe(struct spi_device *spi)
 204 {
 205         int ret = 0;
 206
 207         g_spi = spi;
 208         spi->bits_per_word = 8;
 209
 210         if (!get_slic_product_code(spi))
 211                 return ret;
 212
 213         ret = slic_ds26522_init_configure(spi);
 214         if (ret == 0)
 215                 pr_info("DS26522 cs%d configured\n", spi_get_chipselect(spi, 0));
 216
 217         return ret;
 218 }
 219
 220 static const struct spi_device_id slic_ds26522_id[] = {
 221         { .name = "ds26522" },
 222         { /* sentinel */ },
 223 };
 224 MODULE_DEVICE_TABLE(spi, slic_ds26522_id);
 225
 226 static const struct of_device_id slic_ds26522_match[] = {
 227         {
 228          .compatible = "maxim,ds26522",
 229          },
 230         {},
 231 };
 232 MODULE_DEVICE_TABLE(of, slic_ds26522_match);
 233
 234 static struct spi_driver slic_ds26522_driver = {
 235         .driver = {
 236                    .name = "ds26522",
 237                    .bus = &spi_bus_type,
 238                    .of_match_table = slic_ds26522_match,
 239                    },
 240         .probe = slic_ds26522_probe,
 241         .remove = slic_ds26522_remove,
 242         .id_table = slic_ds26522_id,
 243 };
 244
 245 module_spi_driver(slic_ds26522_driver);