drivers/spi/spi-fsl-lib.c

   1 /*
   2  * Freescale SPI/eSPI controller driver library.
   3  *
   4  * Maintainer: Kumar Gala
   5  *
   6  * Copyright (C) 2006 Polycom, Inc.
   7  *
   8  * CPM SPI and QE buffer descriptors mode support:
   9  * Copyright (c) 2009  MontaVista Software, Inc.
  10  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
  11  *
  12  * Copyright 2010 Freescale Semiconductor, Inc.
  13  *
  14  * This program is free software; you can redistribute  it and/or modify it
  15  * under  the terms of  the GNU General  Public License as published by the
  16  * Free Software Foundation;  either version 2 of the  License, or (at your
  17  * option) any later version.
  18  */
  19 #include <linux/kernel.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/fsl_devices.h>
  22 #include <linux/dma-mapping.h>
  23 #include <linux/mm.h>
  24 #include <linux/of_platform.h>
  25 #include <linux/spi/spi.h>
  26 #ifdef CONFIG_FSL_SOC
  27 #include <sysdev/fsl_soc.h>
  28 #endif
  29
  30 #include "spi-fsl-lib.h"
  31
  32 #define MPC8XXX_SPI_RX_BUF(type)                                          \
  33 void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
  34 {                                                                         \
  35         type *rx = mpc8xxx_spi->rx;                                       \
  36         *rx++ = (type)(data >> mpc8xxx_spi->rx_shift);                    \
  37         mpc8xxx_spi->rx = rx;                                             \
  38 }
  39
  40 #define MPC8XXX_SPI_TX_BUF(type)                                \
  41 u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)  \
  42 {                                                               \
  43         u32 data;                                               \
  44         const type *tx = mpc8xxx_spi->tx;                       \
  45         if (!tx)                                                \
  46                 return 0;                                       \
  47         data = *tx++ << mpc8xxx_spi->tx_shift;                  \
  48         mpc8xxx_spi->tx = tx;                                   \
  49         return data;                                            \
  50 }
  51
  52 MPC8XXX_SPI_RX_BUF(u8)
  53 MPC8XXX_SPI_RX_BUF(u16)
  54 MPC8XXX_SPI_RX_BUF(u32)
  55 MPC8XXX_SPI_TX_BUF(u8)
  56 MPC8XXX_SPI_TX_BUF(u16)
  57 MPC8XXX_SPI_TX_BUF(u32)
  58
  59 struct mpc8xxx_spi_probe_info *to_of_pinfo(struct fsl_spi_platform_data *pdata)
  60 {
  61         return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
  62 }
  63
  64 static void mpc8xxx_spi_work(struct work_struct *work)
  65 {
  66         struct mpc8xxx_spi *mpc8xxx_spi = container_of(work, struct mpc8xxx_spi,
  67                                                        work);
  68
  69         spin_lock_irq(&mpc8xxx_spi->lock);
  70         while (!list_empty(&mpc8xxx_spi->queue)) {
  71                 struct spi_message *m = container_of(mpc8xxx_spi->queue.next,
  72                                                    struct spi_message, queue);
  73
  74                 list_del_init(&m->queue);
  75                 spin_unlock_irq(&mpc8xxx_spi->lock);
  76
  77                 if (mpc8xxx_spi->spi_do_one_msg)
  78                         mpc8xxx_spi->spi_do_one_msg(m);
  79
  80                 spin_lock_irq(&mpc8xxx_spi->lock);
  81         }
  82         spin_unlock_irq(&mpc8xxx_spi->lock);
  83 }
  84
  85 int mpc8xxx_spi_transfer(struct spi_device *spi,
  86                                 struct spi_message *m)
  87 {
  88         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
  89         unsigned long flags;
  90
  91         m->actual_length = 0;
  92         m->status = -EINPROGRESS;
  93
  94         spin_lock_irqsave(&mpc8xxx_spi->lock, flags);
  95         list_add_tail(&m->queue, &mpc8xxx_spi->queue);
  96         queue_work(mpc8xxx_spi->workqueue, &mpc8xxx_spi->work);
  97         spin_unlock_irqrestore(&mpc8xxx_spi->lock, flags);
  98
  99         return 0;
 100 }
 101
 102 void mpc8xxx_spi_cleanup(struct spi_device *spi)
 103 {
 104         kfree(spi->controller_state);
 105 }
 106
 107 const char *mpc8xxx_spi_strmode(unsigned int flags)
 108 {
 109         if (flags & SPI_QE_CPU_MODE) {
 110                 return "QE CPU";
 111         } else if (flags & SPI_CPM_MODE) {
 112                 if (flags & SPI_QE)
 113                         return "QE";
 114                 else if (flags & SPI_CPM2)
 115                         return "CPM2";
 116                 else
 117                         return "CPM1";
 118         }
 119         return "CPU";
 120 }
 121
 122 int mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
 123                         unsigned int irq)
 124 {
 125         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
 126         struct spi_master *master;
 127         struct mpc8xxx_spi *mpc8xxx_spi;
 128         int ret = 0;
 129
 130         master = dev_get_drvdata(dev);
 131
 132         /* the spi->mode bits understood by this driver: */
 133         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
 134                         | SPI_LSB_FIRST | SPI_LOOP;
 135
 136         master->transfer = mpc8xxx_spi_transfer;
 137         master->cleanup = mpc8xxx_spi_cleanup;
 138         master->dev.of_node = dev->of_node;
 139
 140         mpc8xxx_spi = spi_master_get_devdata(master);
 141         mpc8xxx_spi->dev = dev;
 142         mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
 143         mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
 144         mpc8xxx_spi->flags = pdata->flags;
 145         mpc8xxx_spi->spibrg = pdata->sysclk;
 146         mpc8xxx_spi->irq = irq;
 147
 148         mpc8xxx_spi->rx_shift = 0;
 149         mpc8xxx_spi->tx_shift = 0;
 150
 151         init_completion(&mpc8xxx_spi->done);
 152
 153         master->bus_num = pdata->bus_num;
 154         master->num_chipselect = pdata->max_chipselect;
 155
 156         spin_lock_init(&mpc8xxx_spi->lock);
 157         init_completion(&mpc8xxx_spi->done);
 158         INIT_WORK(&mpc8xxx_spi->work, mpc8xxx_spi_work);
 159         INIT_LIST_HEAD(&mpc8xxx_spi->queue);
 160
 161         mpc8xxx_spi->workqueue = create_singlethread_workqueue(
 162                 dev_name(master->dev.parent));
 163         if (mpc8xxx_spi->workqueue == NULL) {
 164                 ret = -EBUSY;
 165                 goto err;
 166         }
 167
 168         return 0;
 169
 170 err:
 171         return ret;
 172 }
 173
 174 int mpc8xxx_spi_remove(struct device *dev)
 175 {
 176         struct mpc8xxx_spi *mpc8xxx_spi;
 177         struct spi_master *master;
 178
 179         master = dev_get_drvdata(dev);
 180         mpc8xxx_spi = spi_master_get_devdata(master);
 181
 182         flush_workqueue(mpc8xxx_spi->workqueue);
 183         destroy_workqueue(mpc8xxx_spi->workqueue);
 184         spi_unregister_master(master);
 185
 186         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 187
 188         if (mpc8xxx_spi->spi_remove)
 189                 mpc8xxx_spi->spi_remove(mpc8xxx_spi);
 190
 191         return 0;
 192 }
 193
 194 int of_mpc8xxx_spi_probe(struct platform_device *ofdev)
 195 {
 196         struct device *dev = &ofdev->dev;
 197         struct device_node *np = ofdev->dev.of_node;
 198         struct mpc8xxx_spi_probe_info *pinfo;
 199         struct fsl_spi_platform_data *pdata;
 200         const void *prop;
 201         int ret = -ENOMEM;
 202
 203         pinfo = devm_kzalloc(&ofdev->dev, sizeof(*pinfo), GFP_KERNEL);
 204         if (!pinfo)
 205                 return -ENOMEM;
 206
 207         pdata = &pinfo->pdata;
 208         dev->platform_data = pdata;
 209
 210         /* Allocate bus num dynamically. */
 211         pdata->bus_num = -1;
 212
 213 #ifdef CONFIG_FSL_SOC
 214         /* SPI controller is either clocked from QE or SoC clock. */
 215         pdata->sysclk = get_brgfreq();
 216         if (pdata->sysclk == -1) {
 217                 pdata->sysclk = fsl_get_sys_freq();
 218                 if (pdata->sysclk == -1)
 219                         return -ENODEV;
 220         }
 221 #else
 222         ret = of_property_read_u32(np, "clock-frequency", &pdata->sysclk);
 223         if (ret)
 224                 return ret;
 225 #endif
 226
 227         prop = of_get_property(np, "mode", NULL);
 228         if (prop && !strcmp(prop, "cpu-qe"))
 229                 pdata->flags = SPI_QE_CPU_MODE;
 230         else if (prop && !strcmp(prop, "qe"))
 231                 pdata->flags = SPI_CPM_MODE | SPI_QE;
 232         else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
 233                 pdata->flags = SPI_CPM_MODE | SPI_CPM2;
 234         else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
 235                 pdata->flags = SPI_CPM_MODE | SPI_CPM1;
 236
 237         return 0;
 238 }