diff options
Diffstat (limited to 'drivers/spi/mpc512x_psc_spi.c')
-rw-r--r-- | drivers/spi/mpc512x_psc_spi.c | 576 |
1 files changed, 576 insertions, 0 deletions
diff --git a/drivers/spi/mpc512x_psc_spi.c b/drivers/spi/mpc512x_psc_spi.c new file mode 100644 index 000000000000..28a126d2742b --- /dev/null +++ b/drivers/spi/mpc512x_psc_spi.c @@ -0,0 +1,576 @@ +/* + * MPC512x PSC in SPI mode driver. + * + * Copyright (C) 2007,2008 Freescale Semiconductor Inc. + * Original port from 52xx driver: + * Hongjun Chen <hong-jun.chen@freescale.com> + * + * Fork of mpc52xx_psc_spi.c: + * Copyright (C) 2006 TOPTICA Photonics AG., Dragos Carp + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/of_platform.h> +#include <linux/workqueue.h> +#include <linux/completion.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/spi/spi.h> +#include <linux/fsl_devices.h> +#include <asm/mpc52xx_psc.h> + +struct mpc512x_psc_spi { + void (*cs_control)(struct spi_device *spi, bool on); + u32 sysclk; + + /* driver internal data */ + struct mpc52xx_psc __iomem *psc; + struct mpc512x_psc_fifo __iomem *fifo; + unsigned int irq; + u8 bits_per_word; + u8 busy; + u32 mclk; + u8 eofbyte; + + struct workqueue_struct *workqueue; + struct work_struct work; + + struct list_head queue; + spinlock_t lock; /* Message queue lock */ + + struct completion done; +}; + +/* controller state */ +struct mpc512x_psc_spi_cs { + int bits_per_word; + int speed_hz; +}; + +/* set clock freq, clock ramp, bits per work + * if t is NULL then reset the values to the default values + */ +static int mpc512x_psc_spi_transfer_setup(struct spi_device *spi, + struct spi_transfer *t) +{ + struct mpc512x_psc_spi_cs *cs = spi->controller_state; + + cs->speed_hz = (t && t->speed_hz) + ? t->speed_hz : spi->max_speed_hz; + cs->bits_per_word = (t && t->bits_per_word) + ? t->bits_per_word : spi->bits_per_word; + cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8; + return 0; +} + +static void mpc512x_psc_spi_activate_cs(struct spi_device *spi) +{ + struct mpc512x_psc_spi_cs *cs = spi->controller_state; + struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master); + struct mpc52xx_psc __iomem *psc = mps->psc; + u32 sicr; + u32 ccr; + u16 bclkdiv; + + sicr = in_be32(&psc->sicr); + + /* Set clock phase and polarity */ + if (spi->mode & SPI_CPHA) + sicr |= 0x00001000; + else + sicr &= ~0x00001000; + + if (spi->mode & SPI_CPOL) + sicr |= 0x00002000; + else + sicr &= ~0x00002000; + + if (spi->mode & SPI_LSB_FIRST) + sicr |= 0x10000000; + else + sicr &= ~0x10000000; + out_be32(&psc->sicr, sicr); + + ccr = in_be32(&psc->ccr); + ccr &= 0xFF000000; + if (cs->speed_hz) + bclkdiv = (mps->mclk / cs->speed_hz) - 1; + else + bclkdiv = (mps->mclk / 1000000) - 1; /* default 1MHz */ + + ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8)); + out_be32(&psc->ccr, ccr); + mps->bits_per_word = cs->bits_per_word; + + if (mps->cs_control) + mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0); +} + +static void mpc512x_psc_spi_deactivate_cs(struct spi_device *spi) +{ + struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master); + + if (mps->cs_control) + mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1); + +} + +/* extract and scale size field in txsz or rxsz */ +#define MPC512x_PSC_FIFO_SZ(sz) ((sz & 0x7ff) << 2); + +#define EOFBYTE 1 + +static int mpc512x_psc_spi_transfer_rxtx(struct spi_device *spi, + struct spi_transfer *t) +{ + struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master); + struct mpc52xx_psc __iomem *psc = mps->psc; + struct mpc512x_psc_fifo __iomem *fifo = mps->fifo; + size_t len = t->len; + u8 *tx_buf = (u8 *)t->tx_buf; + u8 *rx_buf = (u8 *)t->rx_buf; + + if (!tx_buf && !rx_buf && t->len) + return -EINVAL; + + /* Zero MR2 */ + in_8(&psc->mode); + out_8(&psc->mode, 0x0); + + while (len) { + int count; + int i; + u8 data; + size_t fifosz; + int rxcount; + + /* + * The number of bytes that can be sent at a time + * depends on the fifo size. + */ + fifosz = MPC512x_PSC_FIFO_SZ(in_be32(&fifo->txsz)); + count = min(fifosz, len); + + for (i = count; i > 0; i--) { + data = tx_buf ? *tx_buf++ : 0; + if (len == EOFBYTE) + setbits32(&fifo->txcmd, MPC512x_PSC_FIFO_EOF); + out_8(&fifo->txdata_8, data); + len--; + } + + INIT_COMPLETION(mps->done); + + /* interrupt on tx fifo empty */ + out_be32(&fifo->txisr, MPC512x_PSC_FIFO_EMPTY); + out_be32(&fifo->tximr, MPC512x_PSC_FIFO_EMPTY); + + /* enable transmiter/receiver */ + out_8(&psc->command, + MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE); + + wait_for_completion(&mps->done); + + mdelay(1); + + /* rx fifo should have count bytes in it */ + rxcount = in_be32(&fifo->rxcnt); + if (rxcount != count) + mdelay(1); + + rxcount = in_be32(&fifo->rxcnt); + if (rxcount != count) { + dev_warn(&spi->dev, "expected %d bytes in rx fifo " + "but got %d\n", count, rxcount); + } + + rxcount = min(rxcount, count); + for (i = rxcount; i > 0; i--) { + data = in_8(&fifo->rxdata_8); + if (rx_buf) + *rx_buf++ = data; + } + while (in_be32(&fifo->rxcnt)) { + in_8(&fifo->rxdata_8); + } + + out_8(&psc->command, + MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); + } + /* disable transmiter/receiver and fifo interrupt */ + out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); + out_be32(&fifo->tximr, 0); + return 0; +} + +static void mpc512x_psc_spi_work(struct work_struct *work) +{ + struct mpc512x_psc_spi *mps = container_of(work, + struct mpc512x_psc_spi, + work); + + spin_lock_irq(&mps->lock); + mps->busy = 1; + while (!list_empty(&mps->queue)) { + struct spi_message *m; + struct spi_device *spi; + struct spi_transfer *t = NULL; + unsigned cs_change; + int status; + + m = container_of(mps->queue.next, struct spi_message, queue); + list_del_init(&m->queue); + spin_unlock_irq(&mps->lock); + + spi = m->spi; + cs_change = 1; + status = 0; + list_for_each_entry(t, &m->transfers, transfer_list) { + if (t->bits_per_word || t->speed_hz) { + status = mpc512x_psc_spi_transfer_setup(spi, t); + if (status < 0) + break; + } + + if (cs_change) + mpc512x_psc_spi_activate_cs(spi); + cs_change = t->cs_change; + + status = mpc512x_psc_spi_transfer_rxtx(spi, t); + if (status) + break; + m->actual_length += t->len; + + if (t->delay_usecs) + udelay(t->delay_usecs); + + if (cs_change) + mpc512x_psc_spi_deactivate_cs(spi); + } + + m->status = status; + m->complete(m->context); + + if (status || !cs_change) + mpc512x_psc_spi_deactivate_cs(spi); + + mpc512x_psc_spi_transfer_setup(spi, NULL); + + spin_lock_irq(&mps->lock); + } + mps->busy = 0; + spin_unlock_irq(&mps->lock); +} + +static int mpc512x_psc_spi_setup(struct spi_device *spi) +{ + struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master); + struct mpc512x_psc_spi_cs *cs = spi->controller_state; + unsigned long flags; + + if (spi->bits_per_word % 8) + return -EINVAL; + + if (!cs) { + cs = kzalloc(sizeof *cs, GFP_KERNEL); + if (!cs) + return -ENOMEM; + spi->controller_state = cs; + } + + cs->bits_per_word = spi->bits_per_word; + cs->speed_hz = spi->max_speed_hz; + + spin_lock_irqsave(&mps->lock, flags); + if (!mps->busy) + mpc512x_psc_spi_deactivate_cs(spi); + spin_unlock_irqrestore(&mps->lock, flags); + + return 0; +} + +static int mpc512x_psc_spi_transfer(struct spi_device *spi, + struct spi_message *m) +{ + struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master); + unsigned long flags; + + m->actual_length = 0; + m->status = -EINPROGRESS; + + spin_lock_irqsave(&mps->lock, flags); + list_add_tail(&m->queue, &mps->queue); + queue_work(mps->workqueue, &mps->work); + spin_unlock_irqrestore(&mps->lock, flags); + + return 0; +} + +static void mpc512x_psc_spi_cleanup(struct spi_device *spi) +{ + kfree(spi->controller_state); +} + +static int mpc512x_psc_spi_port_config(struct spi_master *master, + struct mpc512x_psc_spi *mps) +{ + struct mpc52xx_psc __iomem *psc = mps->psc; + struct mpc512x_psc_fifo __iomem *fifo = mps->fifo; + struct clk *spiclk; + int ret = 0; + char name[32]; + u32 sicr; + u32 ccr; + u16 bclkdiv; + + sprintf(name, "psc%d_mclk", master->bus_num); + spiclk = clk_get(&master->dev, name); + clk_enable(spiclk); + mps->mclk = clk_get_rate(spiclk); + clk_put(spiclk); + + /* Reset the PSC into a known state */ + out_8(&psc->command, MPC52xx_PSC_RST_RX); + out_8(&psc->command, MPC52xx_PSC_RST_TX); + out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); + + /* Disable psc interrupts all useful interrupts are in fifo */ + out_be16(&psc->isr_imr.imr, 0); + + /* Disable fifo interrupts, will be enabled later */ + out_be32(&fifo->tximr, 0); + out_be32(&fifo->rximr, 0); + + /* Setup fifo slice address and size */ + /*out_be32(&fifo->txsz, 0x0fe00004);*/ + /*out_be32(&fifo->rxsz, 0x0ff00004);*/ + + sicr = 0x01000000 | /* SIM = 0001 -- 8 bit */ + 0x00800000 | /* GenClk = 1 -- internal clk */ + 0x00008000 | /* SPI = 1 */ + 0x00004000 | /* MSTR = 1 -- SPI master */ + 0x00000800; /* UseEOF = 1 -- SS low until EOF */ + + out_be32(&psc->sicr, sicr); + + ccr = in_be32(&psc->ccr); + ccr &= 0xFF000000; + bclkdiv = (mps->mclk / 1000000) - 1; /* default 1MHz */ + ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8)); + out_be32(&psc->ccr, ccr); + + /* Set 2ms DTL delay */ + out_8(&psc->ctur, 0x00); + out_8(&psc->ctlr, 0x82); + + /* we don't use the alarms */ + out_be32(&fifo->rxalarm, 0xfff); + out_be32(&fifo->txalarm, 0); + + /* Enable FIFO slices for Rx/Tx */ + out_be32(&fifo->rxcmd, + MPC512x_PSC_FIFO_ENABLE_SLICE | MPC512x_PSC_FIFO_ENABLE_DMA); + out_be32(&fifo->txcmd, + MPC512x_PSC_FIFO_ENABLE_SLICE | MPC512x_PSC_FIFO_ENABLE_DMA); + + mps->bits_per_word = 8; + + return ret; +} + +static irqreturn_t mpc512x_psc_spi_isr(int irq, void *dev_id) +{ + struct mpc512x_psc_spi *mps = (struct mpc512x_psc_spi *)dev_id; + struct mpc512x_psc_fifo __iomem *fifo = mps->fifo; + + /* clear interrupt and wake up the work queue */ + if (in_be32(&fifo->txisr) & + in_be32(&fifo->tximr) & MPC512x_PSC_FIFO_EMPTY) { + out_be32(&fifo->txisr, MPC512x_PSC_FIFO_EMPTY); + out_be32(&fifo->tximr, 0); + complete(&mps->done); + return IRQ_HANDLED; + } + return IRQ_NONE; +} + +/* bus_num is used only for the case dev->platform_data == NULL */ +static int __init mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr, + u32 size, unsigned int irq, + s16 bus_num) +{ + struct fsl_spi_platform_data *pdata = dev->platform_data; + struct mpc512x_psc_spi *mps; + struct spi_master *master; + int ret; + void *tempp; + + master = spi_alloc_master(dev, sizeof *mps); + if (master == NULL) + return -ENOMEM; + + dev_set_drvdata(dev, master); + mps = spi_master_get_devdata(master); + mps->irq = irq; + + if (pdata == NULL) { + dev_err(dev, "probe called without platform data, no " + "cs_control function will be called\n"); + mps->cs_control = NULL; + mps->sysclk = 0; + master->bus_num = bus_num; + master->num_chipselect = 255; + } else { + mps->cs_control = pdata->cs_control; + mps->sysclk = pdata->sysclk; + master->bus_num = pdata->bus_num; + master->num_chipselect = pdata->max_chipselect; + } + + master->setup = mpc512x_psc_spi_setup; + master->transfer = mpc512x_psc_spi_transfer; + master->cleanup = mpc512x_psc_spi_cleanup; + + tempp = ioremap(regaddr, size); + if (!tempp) { + dev_err(dev, "could not ioremap I/O port range\n"); + ret = -EFAULT; + goto free_master; + } + mps->psc = tempp; + mps->fifo = + (struct mpc512x_psc_fifo *)(tempp + sizeof(struct mpc52xx_psc)); + + ret = request_irq(mps->irq, mpc512x_psc_spi_isr, IRQF_SHARED, + "mpc512x-psc-spi", mps); + if (ret) + goto free_master; + + ret = mpc512x_psc_spi_port_config(master, mps); + if (ret < 0) + goto free_irq; + + spin_lock_init(&mps->lock); + init_completion(&mps->done); + INIT_WORK(&mps->work, mpc512x_psc_spi_work); + INIT_LIST_HEAD(&mps->queue); + + mps->workqueue = + create_singlethread_workqueue(dev_name(master->dev.parent)); + if (mps->workqueue == NULL) { + ret = -EBUSY; + goto free_irq; + } + + ret = spi_register_master(master); + if (ret < 0) + goto unreg_master; + + return ret; + +unreg_master: + destroy_workqueue(mps->workqueue); +free_irq: + free_irq(mps->irq, mps); +free_master: + if (mps->psc) + iounmap(mps->psc); + spi_master_put(master); + + return ret; +} + +static int __exit mpc512x_psc_spi_do_remove(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct mpc512x_psc_spi *mps = spi_master_get_devdata(master); + + flush_workqueue(mps->workqueue); + destroy_workqueue(mps->workqueue); + spi_unregister_master(master); + free_irq(mps->irq, mps); + if (mps->psc) + iounmap(mps->psc); + + return 0; +} + +static int __init mpc512x_psc_spi_of_probe(struct of_device *op, + const struct of_device_id *match) +{ + const u32 *regaddr_p; + u64 regaddr64, size64; + s16 id = -1; + + regaddr_p = of_get_address(op->node, 0, &size64, NULL); + if (!regaddr_p) { + dev_err(&op->dev, "Invalid PSC address\n"); + return -EINVAL; + } + regaddr64 = of_translate_address(op->node, regaddr_p); + + /* get PSC id (0..11, used by port_config) */ + if (op->dev.platform_data == NULL) { + const u32 *psc_nump; + + psc_nump = of_get_property(op->node, "cell-index", NULL); + if (!psc_nump || *psc_nump > 11) { + dev_err(&op->dev, "mpc512x_psc_spi: Device node %s " + "has invalid cell-index property\n", + op->node->full_name); + return -EINVAL; + } + id = *psc_nump; + } + + return mpc512x_psc_spi_do_probe(&op->dev, (u32) regaddr64, (u32) size64, + irq_of_parse_and_map(op->node, 0), id); +} + +static int __exit mpc512x_psc_spi_of_remove(struct of_device *op) +{ + return mpc512x_psc_spi_do_remove(&op->dev); +} + +static struct of_device_id mpc512x_psc_spi_of_match[] = { + { .compatible = "fsl,mpc5121-psc-spi", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, mpc512x_psc_spi_of_match); + +static struct of_platform_driver mpc512x_psc_spi_of_driver = { + .match_table = mpc512x_psc_spi_of_match, + .probe = mpc512x_psc_spi_of_probe, + .remove = __exit_p(mpc512x_psc_spi_of_remove), + .driver = { + .name = "mpc512x-psc-spi", + .owner = THIS_MODULE, + }, +}; + +static int __init mpc512x_psc_spi_init(void) +{ + return of_register_platform_driver(&mpc512x_psc_spi_of_driver); +} +module_init(mpc512x_psc_spi_init); + +static void __exit mpc512x_psc_spi_exit(void) +{ + of_unregister_platform_driver(&mpc512x_psc_spi_of_driver); +} +module_exit(mpc512x_psc_spi_exit); + +MODULE_AUTHOR("John Rigby"); +MODULE_DESCRIPTION("MPC512x PSC SPI Driver"); +MODULE_LICENSE("GPL"); |