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 <[email protected]>
  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/dma-mapping.h>
  20 #include <linux/fsl_devices.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/kernel.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 const char *mpc8xxx_spi_strmode(unsigned int flags)
 103 {
 104         if (flags & SPI_QE_CPU_MODE) {
 105                 return "QE CPU";
 106         } else if (flags & SPI_CPM_MODE) {
 107                 if (flags & SPI_QE)
 108                         return "QE";
 109                 else if (flags & SPI_CPM2)
 110                         return "CPM2";
 111                 else
 112                         return "CPM1";
 113         }
 114         return "CPU";
 115 }
 116
 117 int mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
 118                         unsigned int irq)
 119 {
 120         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
 121         struct spi_master *master;
 122         struct mpc8xxx_spi *mpc8xxx_spi;
 123         int ret = 0;
 124
 125         master = dev_get_drvdata(dev);
 126
 127         /* the spi->mode bits understood by this driver: */
 128         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
 129                         | SPI_LSB_FIRST | SPI_LOOP;
 130
 131         master->transfer = mpc8xxx_spi_transfer;
 132         master->dev.of_node = dev->of_node;
 133
 134         mpc8xxx_spi = spi_master_get_devdata(master);
 135         mpc8xxx_spi->dev = dev;
 136         mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
 137         mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
 138         mpc8xxx_spi->flags = pdata->flags;
 139         mpc8xxx_spi->spibrg = pdata->sysclk;
 140         mpc8xxx_spi->irq = irq;
 141
 142         mpc8xxx_spi->rx_shift = 0;
 143         mpc8xxx_spi->tx_shift = 0;
 144
 145         init_completion(&mpc8xxx_spi->done);
 146
 147         master->bus_num = pdata->bus_num;
 148         master->num_chipselect = pdata->max_chipselect;
 149
 150         spin_lock_init(&mpc8xxx_spi->lock);
 151         init_completion(&mpc8xxx_spi->done);
 152         INIT_WORK(&mpc8xxx_spi->work, mpc8xxx_spi_work);
 153         INIT_LIST_HEAD(&mpc8xxx_spi->queue);
 154
 155         mpc8xxx_spi->workqueue = create_singlethread_workqueue(
 156                 dev_name(master->dev.parent));
 157         if (mpc8xxx_spi->workqueue == NULL) {
 158                 ret = -EBUSY;
 159                 goto err;
 160         }
 161
 162         return 0;
 163
 164 err:
 165         return ret;
 166 }
 167
 168 int mpc8xxx_spi_remove(struct device *dev)
 169 {
 170         struct mpc8xxx_spi *mpc8xxx_spi;
 171         struct spi_master *master;
 172
 173         master = dev_get_drvdata(dev);
 174         mpc8xxx_spi = spi_master_get_devdata(master);
 175
 176         flush_workqueue(mpc8xxx_spi->workqueue);
 177         destroy_workqueue(mpc8xxx_spi->workqueue);
 178         spi_unregister_master(master);
 179
 180         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 181
 182         if (mpc8xxx_spi->spi_remove)
 183                 mpc8xxx_spi->spi_remove(mpc8xxx_spi);
 184
 185         return 0;
 186 }
 187
 188 int of_mpc8xxx_spi_probe(struct platform_device *ofdev)
 189 {
 190         struct device *dev = &ofdev->dev;
 191         struct device_node *np = ofdev->dev.of_node;
 192         struct mpc8xxx_spi_probe_info *pinfo;
 193         struct fsl_spi_platform_data *pdata;
 194         const void *prop;
 195         int ret = -ENOMEM;
 196
 197         pinfo = devm_kzalloc(&ofdev->dev, sizeof(*pinfo), GFP_KERNEL);
 198         if (!pinfo)
 199                 return ret;
 200
 201         pdata = &pinfo->pdata;
 202         dev->platform_data = pdata;
 203
 204         /* Allocate bus num dynamically. */
 205         pdata->bus_num = -1;
 206
 207 #ifdef CONFIG_FSL_SOC
 208         /* SPI controller is either clocked from QE or SoC clock. */
 209         pdata->sysclk = get_brgfreq();
 210         if (pdata->sysclk == -1) {
 211                 pdata->sysclk = fsl_get_sys_freq();
 212                 if (pdata->sysclk == -1)
 213                         return -ENODEV;
 214         }
 215 #else
 216         ret = of_property_read_u32(np, "clock-frequency", &pdata->sysclk);
 217         if (ret)
 218                 return ret;
 219 #endif
 220
 221         prop = of_get_property(np, "mode", NULL);
 222         if (prop && !strcmp(prop, "cpu-qe"))
 223                 pdata->flags = SPI_QE_CPU_MODE;
 224         else if (prop && !strcmp(prop, "qe"))
 225                 pdata->flags = SPI_CPM_MODE | SPI_QE;
 226         else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
 227                 pdata->flags = SPI_CPM_MODE | SPI_CPM2;
 228         else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
 229                 pdata->flags = SPI_CPM_MODE | SPI_CPM1;
 230
 231         return 0;
 232 }