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/of_spi.h>
  26 #include <sysdev/fsl_soc.h>
  27
  28 #include "spi_fsl_lib.h"
  29
  30 #define MPC8XXX_SPI_RX_BUF(type)                                          \
  31 void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
  32 {                                                                         \
  33         type *rx = mpc8xxx_spi->rx;                                       \
  34         *rx++ = (type)(data >> mpc8xxx_spi->rx_shift);                    \
  35         mpc8xxx_spi->rx = rx;                                             \
  36 }
  37
  38 #define MPC8XXX_SPI_TX_BUF(type)                                \
  39 u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)  \
  40 {                                                               \
  41         u32 data;                                               \
  42         const type *tx = mpc8xxx_spi->tx;                       \
  43         if (!tx)                                                \
  44                 return 0;                                       \
  45         data = *tx++ << mpc8xxx_spi->tx_shift;                  \
  46         mpc8xxx_spi->tx = tx;                                   \
  47         return data;                                            \
  48 }
  49
  50 MPC8XXX_SPI_RX_BUF(u8)
  51 MPC8XXX_SPI_RX_BUF(u16)
  52 MPC8XXX_SPI_RX_BUF(u32)
  53 MPC8XXX_SPI_TX_BUF(u8)
  54 MPC8XXX_SPI_TX_BUF(u16)
  55 MPC8XXX_SPI_TX_BUF(u32)
  56
  57 struct mpc8xxx_spi_probe_info *to_of_pinfo(struct fsl_spi_platform_data *pdata)
  58 {
  59         return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
  60 }
  61
  62 void mpc8xxx_spi_work(struct work_struct *work)
  63 {
  64         struct mpc8xxx_spi *mpc8xxx_spi = container_of(work, struct mpc8xxx_spi,
  65                                                        work);
  66
  67         spin_lock_irq(&mpc8xxx_spi->lock);
  68         while (!list_empty(&mpc8xxx_spi->queue)) {
  69                 struct spi_message *m = container_of(mpc8xxx_spi->queue.next,
  70                                                    struct spi_message, queue);
  71
  72                 list_del_init(&m->queue);
  73                 spin_unlock_irq(&mpc8xxx_spi->lock);
  74
  75                 if (mpc8xxx_spi->spi_do_one_msg)
  76                         mpc8xxx_spi->spi_do_one_msg(m);
  77
  78                 spin_lock_irq(&mpc8xxx_spi->lock);
  79         }
  80         spin_unlock_irq(&mpc8xxx_spi->lock);
  81 }
  82
  83 int mpc8xxx_spi_transfer(struct spi_device *spi,
  84                                 struct spi_message *m)
  85 {
  86         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
  87         unsigned long flags;
  88
  89         m->actual_length = 0;
  90         m->status = -EINPROGRESS;
  91
  92         spin_lock_irqsave(&mpc8xxx_spi->lock, flags);
  93         list_add_tail(&m->queue, &mpc8xxx_spi->queue);
  94         queue_work(mpc8xxx_spi->workqueue, &mpc8xxx_spi->work);
  95         spin_unlock_irqrestore(&mpc8xxx_spi->lock, flags);
  96
  97         return 0;
  98 }
  99
 100 void mpc8xxx_spi_cleanup(struct spi_device *spi)
 101 {
 102         kfree(spi->controller_state);
 103 }
 104
 105 const char *mpc8xxx_spi_strmode(unsigned int flags)
 106 {
 107         if (flags & SPI_QE_CPU_MODE) {
 108                 return "QE CPU";
 109         } else if (flags & SPI_CPM_MODE) {
 110                 if (flags & SPI_QE)
 111                         return "QE";
 112                 else if (flags & SPI_CPM2)
 113                         return "CPM2";
 114                 else
 115                         return "CPM1";
 116         }
 117         return "CPU";
 118 }
 119
 120 int mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
 121                         unsigned int irq)
 122 {
 123         struct fsl_spi_platform_data *pdata = dev->platform_data;
 124         struct spi_master *master;
 125         struct mpc8xxx_spi *mpc8xxx_spi;
 126         int ret = 0;
 127
 128         master = dev_get_drvdata(dev);
 129
 130         /* the spi->mode bits understood by this driver: */
 131         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
 132                         | SPI_LSB_FIRST | SPI_LOOP;
 133
 134         master->transfer = mpc8xxx_spi_transfer;
 135         master->cleanup = mpc8xxx_spi_cleanup;
 136         master->dev.of_node = dev->of_node;
 137
 138         mpc8xxx_spi = spi_master_get_devdata(master);
 139         mpc8xxx_spi->dev = dev;
 140         mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
 141         mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
 142         mpc8xxx_spi->flags = pdata->flags;
 143         mpc8xxx_spi->spibrg = pdata->sysclk;
 144         mpc8xxx_spi->irq = irq;
 145
 146         mpc8xxx_spi->rx_shift = 0;
 147         mpc8xxx_spi->tx_shift = 0;
 148
 149         init_completion(&mpc8xxx_spi->done);
 150
 151         master->bus_num = pdata->bus_num;
 152         master->num_chipselect = pdata->max_chipselect;
 153
 154         spin_lock_init(&mpc8xxx_spi->lock);
 155         init_completion(&mpc8xxx_spi->done);
 156         INIT_WORK(&mpc8xxx_spi->work, mpc8xxx_spi_work);
 157         INIT_LIST_HEAD(&mpc8xxx_spi->queue);
 158
 159         mpc8xxx_spi->workqueue = create_singlethread_workqueue(
 160                 dev_name(master->dev.parent));
 161         if (mpc8xxx_spi->workqueue == NULL) {
 162                 ret = -EBUSY;
 163                 goto err;
 164         }
 165
 166         return 0;
 167
 168 err:
 169         return ret;
 170 }
 171
 172 int __devexit mpc8xxx_spi_remove(struct device *dev)
 173 {
 174         struct mpc8xxx_spi *mpc8xxx_spi;
 175         struct spi_master *master;
 176
 177         master = dev_get_drvdata(dev);
 178         mpc8xxx_spi = spi_master_get_devdata(master);
 179
 180         flush_workqueue(mpc8xxx_spi->workqueue);
 181         destroy_workqueue(mpc8xxx_spi->workqueue);
 182         spi_unregister_master(master);
 183
 184         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 185
 186         if (mpc8xxx_spi->spi_remove)
 187                 mpc8xxx_spi->spi_remove(mpc8xxx_spi);
 188
 189         return 0;
 190 }
 191
 192 int __devinit of_mpc8xxx_spi_probe(struct platform_device *ofdev,
 193                                         const struct of_device_id *ofid)
 194 {
 195         struct device *dev = &ofdev->dev;
 196         struct device_node *np = ofdev->dev.of_node;
 197         struct mpc8xxx_spi_probe_info *pinfo;
 198         struct fsl_spi_platform_data *pdata;
 199         const void *prop;
 200         int ret = -ENOMEM;
 201
 202         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 203         if (!pinfo)
 204                 return -ENOMEM;
 205
 206         pdata = &pinfo->pdata;
 207         dev->platform_data = pdata;
 208
 209         /* Allocate bus num dynamically. */
 210         pdata->bus_num = -1;
 211
 212         /* SPI controller is either clocked from QE or SoC clock. */
 213         pdata->sysclk = get_brgfreq();
 214         if (pdata->sysclk == -1) {
 215                 pdata->sysclk = fsl_get_sys_freq();
 216                 if (pdata->sysclk == -1) {
 217                         ret = -ENODEV;
 218                         goto err;
 219                 }
 220         }
 221
 222         prop = of_get_property(np, "mode", NULL);
 223         if (prop && !strcmp(prop, "cpu-qe"))
 224                 pdata->flags = SPI_QE_CPU_MODE;
 225         else if (prop && !strcmp(prop, "qe"))
 226                 pdata->flags = SPI_CPM_MODE | SPI_QE;
 227         else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
 228                 pdata->flags = SPI_CPM_MODE | SPI_CPM2;
 229         else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
 230                 pdata->flags = SPI_CPM_MODE | SPI_CPM1;
 231
 232         return 0;
 233
 234 err:
 235         kfree(pinfo);
 236         return ret;
 237 }