diff options
author | Dragos Carp <dragos.carp@toptica.com> | 2007-05-11 07:22:52 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-11 17:29:35 +0200 |
commit | 00b8fd236764e3d5bc1d30dc65e256e283de4c3d (patch) | |
tree | 014b5a7a6f194915646713d1324cc02459a01f40 /drivers/spi/mpc52xx_psc_spi.c | |
parent | consolidate generic_writepages and mpage_writepages (diff) | |
download | linux-00b8fd236764e3d5bc1d30dc65e256e283de4c3d.tar.xz linux-00b8fd236764e3d5bc1d30dc65e256e283de4c3d.zip |
MPC52xx PSC SPI master driver
SPI master driver for MPC52xx using its Programmable Serial Controller.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dragos Carp <dragos.carp@toptica.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/spi/mpc52xx_psc_spi.c')
-rw-r--r-- | drivers/spi/mpc52xx_psc_spi.c | 654 |
1 files changed, 654 insertions, 0 deletions
diff --git a/drivers/spi/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c new file mode 100644 index 000000000000..052359fc41ee --- /dev/null +++ b/drivers/spi/mpc52xx_psc_spi.c @@ -0,0 +1,654 @@ +/* + * MPC52xx SPC 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/errno.h> +#include <linux/interrupt.h> + +#if defined(CONFIG_PPC_MERGE) +#include <asm/of_platform.h> +#else +#include <linux/platform_device.h> +#endif + +#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 <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 (*activate_cs)(u8, u8); + void (*deactivate_cs)(u8, u8); + u32 sysclk; + + /* driver internal data */ + struct mpc52xx_psc __iomem *psc; + 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(&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(&psc->ccr, ccr); + mps->bits_per_word = cs->bits_per_word; + + if (mps->activate_cs) + mps->activate_cs(spi->chip_select, + (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->deactivate_cs) + mps->deactivate_cs(spi->chip_select, + (spi->mode & SPI_CS_HIGH) ? 1 : 0); +} + +#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; + 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; + unsigned bpw = mps->bits_per_word / 8; + + 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; + } else { + send_at_once = t->len - sb; + rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb); + } + + dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once); + if (tx_buf) { + for (; send_at_once; sb++, send_at_once--) { + /* set EOF flag */ + if (mps->bits_per_word + && (sb + 1) % bpw == 0) + out_8(&psc->ircr2, 0x01); + out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]); + } + } else { + for (; send_at_once; sb++, send_at_once--) { + /* set EOF flag */ + if (mps->bits_per_word + && ((sb + 1) % bpw) == 0) + out_8(&psc->ircr2, 0x01); + out_8(&psc->mpc52xx_psc_buffer_8, 0); + } + } + + + /* enable interupts 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(&psc->rfalarm, rfalarm); + } + out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY); + wait_for_completion(&mps->done); + recv_at_once = in_be16(&psc->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_cdm __iomem *cdm; + struct mpc52xx_gpio __iomem *gpio; + struct mpc52xx_psc __iomem *psc = mps->psc; + u32 ul; + u32 mclken_div; + int ret = 0; + +#if defined(CONFIG_PPC_MERGE) + cdm = mpc52xx_find_and_map("mpc52xx-cdm"); + gpio = mpc52xx_find_and_map("mpc52xx-gpio"); +#else + cdm = ioremap(MPC52xx_PA(MPC52xx_CDM_OFFSET), MPC52xx_CDM_SIZE); + gpio = ioremap(MPC52xx_PA(MPC52xx_GPIO_OFFSET), MPC52xx_GPIO_SIZE); +#endif + if (!cdm || !gpio) { + printk(KERN_ERR "Error mapping CDM/GPIO\n"); + ret = -EFAULT; + goto unmap_regs; + } + + /* default sysclk is 512MHz */ + mclken_div = 0x8000 | + (((mps->sysclk ? mps->sysclk : 512000000) / MCLK) & 0x1FF); + + switch (psc_id) { + case 1: + ul = in_be32(&gpio->port_config); + ul &= 0xFFFFFFF8; + ul |= 0x00000006; + out_be32(&gpio->port_config, ul); + out_be16(&cdm->mclken_div_psc1, mclken_div); + ul = in_be32(&cdm->clk_enables); + ul |= 0x00000020; + out_be32(&cdm->clk_enables, ul); + break; + case 2: + ul = in_be32(&gpio->port_config); + ul &= 0xFFFFFF8F; + ul |= 0x00000060; + out_be32(&gpio->port_config, ul); + out_be16(&cdm->mclken_div_psc2, mclken_div); + ul = in_be32(&cdm->clk_enables); + ul |= 0x00000040; + out_be32(&cdm->clk_enables, ul); + break; + case 3: + ul = in_be32(&gpio->port_config); + ul &= 0xFFFFF0FF; + ul |= 0x00000600; + out_be32(&gpio->port_config, ul); + out_be16(&cdm->mclken_div_psc3, mclken_div); + ul = in_be32(&cdm->clk_enables); + ul |= 0x00000080; + out_be32(&cdm->clk_enables, ul); + break; + case 6: + ul = in_be32(&gpio->port_config); + ul &= 0xFF8FFFFF; + ul |= 0x00700000; + out_be32(&gpio->port_config, ul); + out_be16(&cdm->mclken_div_psc6, mclken_div); + ul = in_be32(&cdm->clk_enables); + ul |= 0x00000010; + out_be32(&cdm->clk_enables, ul); + break; + default: + ret = -EINVAL; + goto unmap_regs; + } + + /* 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(&psc->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(&psc->ccr, 0x070F); /* by default SPI Clk 1MHz */ + + /* Set 2ms DTL delay */ + out_8(&psc->ctur, 0x00); + out_8(&psc->ctlr, 0x84); + + mps->bits_per_word = 8; + +unmap_regs: + if (cdm) + iounmap(cdm); + if (gpio) + iounmap(gpio); + + return ret; +} + +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; + + if (pdata == NULL) + return -ENODEV; + + 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_warn(dev, "probe called without platform data, no " + "(de)activate_cs function will be called\n"); + mps->activate_cs = NULL; + mps->deactivate_cs = NULL; + mps->sysclk = 0; + master->bus_num = bus_num; + master->num_chipselect = 255; + } else { + mps->activate_cs = pdata->activate_cs; + mps->deactivate_cs = pdata->deactivate_cs; + 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; + + mps->psc = ioremap(regaddr, size); + if (!mps->psc) { + dev_err(dev, "could not ioremap I/O port range\n"); + ret = -EFAULT; + goto free_master; + } + + 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) + 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( + master->cdev.dev->bus_id); + 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; +} + +#if !defined(CONFIG_PPC_MERGE) +static int __init mpc52xx_psc_spi_probe(struct platform_device *dev) +{ + switch(dev->id) { + case 1: + case 2: + case 3: + case 6: + return mpc52xx_psc_spi_do_probe(&dev->dev, + MPC52xx_PA(MPC52xx_PSCx_OFFSET(dev->id)), + MPC52xx_PSC_SIZE, platform_get_irq(dev, 0), dev->id); + default: + return -EINVAL; + } +} + +static int __exit mpc52xx_psc_spi_remove(struct platform_device *dev) +{ + return mpc52xx_psc_spi_do_remove(&dev->dev); +} + +static struct platform_driver mpc52xx_psc_spi_platform_driver = { + .remove = __exit_p(mpc52xx_psc_spi_remove), + .driver = { + .name = "mpc52xx-psc-spi", + .owner = THIS_MODULE, + }, +}; + +static int __init mpc52xx_psc_spi_init(void) +{ + return platform_driver_probe(&mpc52xx_psc_spi_platform_driver, + mpc52xx_psc_spi_probe); +} +module_init(mpc52xx_psc_spi_init); + +static void __exit mpc52xx_psc_spi_exit(void) +{ + platform_driver_unregister(&mpc52xx_psc_spi_platform_driver); +} +module_exit(mpc52xx_psc_spi_exit); + +#else /* defined(CONFIG_PPC_MERGE) */ + +static int __init mpc52xx_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) { + printk(KERN_ERR "Invalid PSC address\n"); + return -EINVAL; + } + regaddr64 = of_translate_address(op->node, regaddr_p); + + if (op->dev.platform_data == NULL) { + struct device_node *np; + int i = 0; + + for_each_node_by_type(np, "spi") { + if (of_find_device_by_node(np) == op) { + id = i; + break; + } + i++; + } + } + + return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64, + irq_of_parse_and_map(op->node, 0), id); +} + +static int __exit mpc52xx_psc_spi_of_remove(struct of_device *op) +{ + return mpc52xx_psc_spi_do_remove(&op->dev); +} + +static struct of_device_id mpc52xx_psc_spi_of_match[] = { + { .type = "spi", .compatible = "mpc52xx-psc-spi", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match); + +static struct of_platform_driver mpc52xx_psc_spi_of_driver = { + .owner = THIS_MODULE, + .name = "mpc52xx-psc-spi", + .match_table = mpc52xx_psc_spi_of_match, + .probe = mpc52xx_psc_spi_of_probe, + .remove = __exit_p(mpc52xx_psc_spi_of_remove), + .driver = { + .name = "mpc52xx-psc-spi", + .owner = THIS_MODULE, + }, +}; + +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); + +#endif /* defined(CONFIG_PPC_MERGE) */ + +MODULE_AUTHOR("Dragos Carp"); +MODULE_DESCRIPTION("MPC52xx PSC SPI Driver"); +MODULE_LICENSE("GPL"); |