/* * MPC52xx PSC in SPI mode driver. * * Maintainer: Dragos Carp * * Copyright (C) 2006 TOPTICA Photonics AG. * * 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/init.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/workqueue.h> #include <linux/completion.h> #include <linux/io.h> #include <linux/delay.h> #include <linux/spi/spi.h> #include <linux/fsl_devices.h> #include <linux/slab.h> #include <asm/mpc52xx.h> #include <asm/mpc52xx_psc.h> #define MCLK 20000000 /* PSC port MClk in hz */ struct mpc52xx_psc_spi { /* fsl_spi_platform data */ void (*cs_control)(struct spi_device *spi, bool on); u32 sysclk; /* driver internal data */ struct mpc52xx_psc __iomem *psc; struct mpc52xx_psc_fifo __iomem *fifo; unsigned int irq; u8 bits_per_word; u8 busy; struct workqueue_struct *workqueue; struct work_struct work; struct list_head queue; spinlock_t lock; struct completion done; }; /* controller state */ struct mpc52xx_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 mpc52xx_psc_spi_transfer_setup(struct spi_device *spi, struct spi_transfer *t) { struct mpc52xx_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 mpc52xx_psc_spi_activate_cs(struct spi_device *spi) { struct mpc52xx_psc_spi_cs *cs = spi->controller_state; struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); struct mpc52xx_psc __iomem *psc = mps->psc; u32 sicr; u16 ccr; 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); /* Set clock frequency and bits per word * Because psc->ccr is defined as 16bit register instead of 32bit * just set the lower byte of BitClkDiv */ ccr = in_be16((u16 __iomem *)&psc->ccr); ccr &= 0xFF00; if (cs->speed_hz) ccr |= (MCLK / cs->speed_hz - 1) & 0xFF; else /* by default SPI Clk 1MHz */ ccr |= (MCLK / 1000000 - 1) & 0xFF; out_be16((u16 __iomem *)&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 mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi) { struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); if (mps->cs_control) mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1); } #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1) /* wake up when 80% fifo full */ #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100) static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi, struct spi_transfer *t) { struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); struct mpc52xx_psc __iomem *psc = mps->psc; struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo; unsigned rb = 0; /* number of bytes receieved */ unsigned sb = 0; /* number of bytes sent */ unsigned char *rx_buf = (unsigned char *)t->rx_buf; unsigned char *tx_buf = (unsigned char *)t->tx_buf; unsigned rfalarm; unsigned send_at_once = MPC52xx_PSC_BUFSIZE; unsigned recv_at_once; int last_block = 0; if (!t->tx_buf && !t->rx_buf && t->len) return -EINVAL; /* enable transmiter/receiver */ out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE); while (rb < t->len) { if (t->len - rb > MPC52xx_PSC_BUFSIZE) { rfalarm = MPC52xx_PSC_RFALARM; last_block = 0; } else { send_at_once = t->len - sb; rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb); last_block = 1; } dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once); for (; send_at_once; sb++, send_at_once--) { /* set EOF flag before the last word is sent */ if (send_at_once == 1 && last_block) out_8(&psc->ircr2, 0x01); if (tx_buf) out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]); else out_8(&psc->mpc52xx_psc_buffer_8, 0); } /* enable interrupts and wait for wake up * if just one byte is expected the Rx FIFO genererates no * FFULL interrupt, so activate the RxRDY interrupt */ out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); if (t->len - rb == 1) { out_8(&psc->mode, 0); } else { out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL); out_be16(&fifo->rfalarm, rfalarm); } out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY); wait_for_completion(&mps->done); recv_at_once = in_be16(&fifo->rfnum); dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once); send_at_once = recv_at_once; if (rx_buf) { for (; recv_at_once; rb++, recv_at_once--) rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8); } else { for (; recv_at_once; rb++, recv_at_once--) in_8(&psc->mpc52xx_psc_buffer_8); } } /* disable transmiter/receiver */ out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); return 0; } static void mpc52xx_psc_spi_work(struct work_struct *work) { struct mpc52xx_psc_spi *mps = container_of(work, struct mpc52xx_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 = mpc52xx_psc_spi_transfer_setup(spi, t); if (status < 0) break; } if (cs_change) mpc52xx_psc_spi_activate_cs(spi); cs_change = t->cs_change; status = mpc52xx_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) mpc52xx_psc_spi_deactivate_cs(spi); } m->status = status; m->complete(m->context); if (status || !cs_change) mpc52xx_psc_spi_deactivate_cs(spi); mpc52xx_psc_spi_transfer_setup(spi, NULL); spin_lock_irq(&mps->lock); } mps->busy = 0; spin_unlock_irq(&mps->lock); } static int mpc52xx_psc_spi_setup(struct spi_device *spi) { struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); struct mpc52xx_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) mpc52xx_psc_spi_deactivate_cs(spi); spin_unlock_irqrestore(&mps->lock, flags); return 0; } static int mpc52xx_psc_spi_transfer(struct spi_device *spi, struct spi_message *m) { struct mpc52xx_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 mpc52xx_psc_spi_cleanup(struct spi_device *spi) { kfree(spi->controller_state); } static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps) { struct mpc52xx_psc __iomem *psc = mps->psc; struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo; u32 mclken_div; int ret; /* default sysclk is 512MHz */ mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK; ret = mpc52xx_set_psc_clkdiv(psc_id, mclken_div); if (ret) return ret; /* 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 interrupts, interrupts are based on alarm level */ out_be16(&psc->mpc52xx_psc_imr, 0); out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); out_8(&fifo->rfcntl, 0); out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL); /* Configure 8bit codec mode as a SPI master and use EOF flags */ /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */ out_be32(&psc->sicr, 0x0180C800); out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */ /* Set 2ms DTL delay */ out_8(&psc->ctur, 0x00); out_8(&psc->ctlr, 0x84); mps->bits_per_word = 8; return 0; } static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id) { struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id; struct mpc52xx_psc __iomem *psc = mps->psc; /* disable interrupt and wake up the work queue */ if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) { out_be16(&psc->mpc52xx_psc_imr, 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 mpc52xx_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 mpc52xx_psc_spi *mps; struct spi_master *master; int ret; master = spi_alloc_master(dev, sizeof *mps); if (master == NULL) return -ENOMEM; dev_set_drvdata(dev, master); mps = spi_master_get_devdata(master); /* the spi->mode bits understood by this driver: */ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; mps->irq = irq; if (pdata == NULL) { dev_warn(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 = mpc52xx_psc_spi_setup; master->transfer = mpc52xx_psc_spi_transfer; master->cleanup = mpc52xx_psc_spi_cleanup; master->dev.of_node = dev->of_node; mps->psc = ioremap(regaddr, size); if (!mps->psc) { dev_err(dev, "could not ioremap I/O port range\n"); ret = -EFAULT; goto free_master; } /* On the 5200, fifo regs are immediately ajacent to the psc regs */ mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc); ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi", mps); if (ret) goto free_master; ret = mpc52xx_psc_spi_port_config(master->bus_num, mps); if (ret < 0) { dev_err(dev, "can't configure PSC! Is it capable of SPI?\n"); goto free_irq; } spin_lock_init(&mps->lock); init_completion(&mps->done); INIT_WORK(&mps->work, mpc52xx_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 mpc52xx_psc_spi_do_remove(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct mpc52xx_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 mpc52xx_psc_spi_of_probe(struct platform_device *op, const struct of_device_id *match) { const u32 *regaddr_p; u64 regaddr64, size64; s16 id = -1; regaddr_p = of_get_address(op->dev.of_node, 0, &size64, NULL); if (!regaddr_p) { dev_err(&op->dev, "Invalid PSC address\n"); return -EINVAL; } regaddr64 = of_translate_address(op->dev.of_node, regaddr_p); /* get PSC id (1..6, used by port_config) */ if (op->dev.platform_data == NULL) { const u32 *psc_nump; psc_nump = of_get_property(op->dev.of_node, "cell-index", NULL); if (!psc_nump || *psc_nump > 5) { dev_err(&op->dev, "Invalid cell-index property\n"); return -EINVAL; } id = *psc_nump + 1; } return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64, irq_of_parse_and_map(op->dev.of_node, 0), id); } static int __exit mpc52xx_psc_spi_of_remove(struct platform_device *op) { return mpc52xx_psc_spi_do_remove(&op->dev); } static const struct of_device_id mpc52xx_psc_spi_of_match[] = { { .compatible = "fsl,mpc5200-psc-spi", }, { .compatible = "mpc5200-psc-spi", }, /* old */ {} }; MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match); static struct of_platform_driver mpc52xx_psc_spi_of_driver = { .probe = mpc52xx_psc_spi_of_probe, .remove = __exit_p(mpc52xx_psc_spi_of_remove), .driver = { .name = "mpc52xx-psc-spi", .owner = THIS_MODULE, .of_match_table = mpc52xx_psc_spi_of_match, }, }; static int __init mpc52xx_psc_spi_init(void) { return of_register_platform_driver(&mpc52xx_psc_spi_of_driver); } module_init(mpc52xx_psc_spi_init); static void __exit mpc52xx_psc_spi_exit(void) { of_unregister_platform_driver(&mpc52xx_psc_spi_of_driver); } module_exit(mpc52xx_psc_spi_exit); MODULE_AUTHOR("Dragos Carp"); MODULE_DESCRIPTION("MPC52xx PSC SPI Driver"); MODULE_LICENSE("GPL");