wbsd.c

The latest MontaVista Linux driver about SD/MMC code

	DBGF("Ending data transfer (%d bytes)\n", data->bytes_xfered);
	
	wbsd_request_end(host, host->mrq);
}

/*
 * MMC Callbacks
 */

static void wbsd_request(struct mmc_host* mmc, struct mmc_request* mrq)
{
	struct wbsd_host* host = mmc_priv(mmc);
	struct mmc_command* cmd;

	/*
	 * Disable tasklets to avoid a deadlock.
	 */
	spin_lock_bh(&host->lock);

	BUG_ON(host->mrq != NULL);

	cmd = mrq->cmd;

	host->mrq = mrq;
	
	/*
	 * If there is no card in the slot then
	 * timeout immediatly.
	 */
	if (!(inb(host->base + WBSD_CSR) & WBSD_CARDPRESENT))
	{
		cmd->error = MMC_ERR_TIMEOUT;
		goto done;
	}

	/*
	 * Does the request include data?
	 */
	if (cmd->data)
	{
		wbsd_prepare_data(host, cmd->data);
		
		if (cmd->data->error != MMC_ERR_NONE)
			goto done;
	}
	
	wbsd_send_command(host, cmd);

	/*
	 * If this is a data transfer the request
	 * will be finished after the data has
	 * transfered.
	 */	
	if (cmd->data && (cmd->error == MMC_ERR_NONE))
	{		
		spin_unlock_bh(&host->lock);

		return;
	}
		
done:
	wbsd_request_end(host, mrq);

	spin_unlock_bh(&host->lock);
}

static void wbsd_set_ios(struct mmc_host* mmc, struct mmc_ios* ios)
{
	struct wbsd_host* host = mmc_priv(mmc);
	u8 clk, setup, pwr;
	
	DBGF("clock %uHz busmode %u powermode %u Vdd %u\n",
		ios->clock, ios->bus_mode, ios->power_mode, ios->vdd);

	spin_lock_bh(&host->lock);

	/*
	 * Reset the chip on each power off.
	 * Should clear out any weird states.
	 */
	if (ios->power_mode == MMC_POWER_OFF)
		wbsd_init_device(host);
	
	if (ios->clock >= 24000000)
		clk = WBSD_CLK_24M;
	else if (ios->clock >= 16000000)
		clk = WBSD_CLK_16M;
	else if (ios->clock >= 12000000)
		clk = WBSD_CLK_12M;
	else
		clk = WBSD_CLK_375K;

	/*
	 * Only write to the clock register when
	 * there is an actual change.
	 */
	if (clk != host->clk)
	{
		wbsd_write_index(host, WBSD_IDX_CLK, clk);
		host->clk = clk;
	}

	if (ios->power_mode != MMC_POWER_OFF)
	{
		/*
		 * Power up card.
		 */
		pwr = inb(host->base + WBSD_CSR);
		pwr &= ~WBSD_POWER_N;
		outb(pwr, host->base + WBSD_CSR);

		/*
		 * This behaviour is stolen from the
		 * Windows driver. Don't know why, but
		 * it is needed.
		 */
		setup = wbsd_read_index(host, WBSD_IDX_SETUP);
		if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
			setup |= WBSD_DAT3_H;
		else
			setup &= ~WBSD_DAT3_H;
		wbsd_write_index(host, WBSD_IDX_SETUP, setup);

		mdelay(1);
	}

	spin_unlock_bh(&host->lock);
}

/*
 * Tasklets
 */

inline static struct mmc_data* wbsd_get_data(struct wbsd_host* host)
{
	WARN_ON(!host->mrq);
	if (!host->mrq)
		return NULL;

	WARN_ON(!host->mrq->cmd);
	if (!host->mrq->cmd)
		return NULL;

	WARN_ON(!host->mrq->cmd->data);
	if (!host->mrq->cmd->data)
		return NULL;
	
	return host->mrq->cmd->data;
}

static void wbsd_tasklet_card(unsigned long param)
{
	struct wbsd_host* host = (struct wbsd_host*)param;
	u8 csr;
	
	spin_lock(&host->lock);
	
	csr = inb(host->base + WBSD_CSR);
	WARN_ON(csr == 0xff);
	
	if (csr & WBSD_CARDPRESENT)
		DBG("Card inserted\n");
	else
	{
		DBG("Card removed\n");
		
		if (host->mrq)
		{
			printk(KERN_ERR DRIVER_NAME
				": Card removed during transfer!\n");
			wbsd_reset(host);
			
			host->mrq->cmd->error = MMC_ERR_FAILED;
			tasklet_schedule(&host->finish_tasklet);
		}
	}
	
	/*
	 * Unlock first since we might get a call back.
	 */
	spin_unlock(&host->lock);

	mmc_detect_change(host->mmc, 0);
}

static void wbsd_tasklet_fifo(unsigned long param)
{
	struct wbsd_host* host = (struct wbsd_host*)param;
	struct mmc_data* data;
	
	spin_lock(&host->lock);
		
	if (!host->mrq)
		goto end;
	
	data = wbsd_get_data(host);
	if (!data)
		goto end;

	if (data->flags & MMC_DATA_WRITE)
		wbsd_fill_fifo(host);
	else
		wbsd_empty_fifo(host);

	/*
	 * Done?
	 */
	if (host->size == data->bytes_xfered)
	{
		wbsd_write_index(host, WBSD_IDX_FIFOEN, 0);
		tasklet_schedule(&host->finish_tasklet);
	}

end:	
	spin_unlock(&host->lock);
}

static void wbsd_tasklet_crc(unsigned long param)
{
	struct wbsd_host* host = (struct wbsd_host*)param;
	struct mmc_data* data;
	
	spin_lock(&host->lock);
	
	WARN_ON(!host->mrq);
	if (!host->mrq)
		goto end;
	
	data = wbsd_get_data(host);
	if (!data)
		goto end;
	
	DBGF("CRC error\n");

	data->error = MMC_ERR_BADCRC;
	
	tasklet_schedule(&host->finish_tasklet);

end:		
	spin_unlock(&host->lock);
}

static void wbsd_tasklet_timeout(unsigned long param)
{
	struct wbsd_host* host = (struct wbsd_host*)param;
	struct mmc_data* data;
	
	spin_lock(&host->lock);
	
	WARN_ON(!host->mrq);
	if (!host->mrq)
		goto end;
	
	data = wbsd_get_data(host);
	if (!data)
		goto end;
	
	DBGF("Timeout\n");

	data->error = MMC_ERR_TIMEOUT;
	
	tasklet_schedule(&host->finish_tasklet);

end:	
	spin_unlock(&host->lock);
}

static void wbsd_tasklet_finish(unsigned long param)
{
	struct wbsd_host* host = (struct wbsd_host*)param;
	struct mmc_data* data;
	
	spin_lock(&host->lock);
	
	WARN_ON(!host->mrq);
	if (!host->mrq)
		goto end;
	
	data = wbsd_get_data(host);
	if (!data)
		goto end;

	wbsd_finish_data(host, data);
	
end:	
	spin_unlock(&host->lock);
}

static void wbsd_tasklet_block(unsigned long param)
{
	struct wbsd_host* host = (struct wbsd_host*)param;
	struct mmc_data* data;
	
	spin_lock(&host->lock);

	if ((wbsd_read_index(host, WBSD_IDX_CRCSTATUS) & WBSD_CRC_MASK) !=
		WBSD_CRC_OK)
	{
		data = wbsd_get_data(host);
		if (!data)
			goto end;
		
		DBGF("CRC error\n");

		data->error = MMC_ERR_BADCRC;
	
		tasklet_schedule(&host->finish_tasklet);
	}

end:	
	spin_unlock(&host->lock);
}

/*
 * Interrupt handling
 */

static irqreturn_t wbsd_irq(int irq, void *dev_id, struct pt_regs *regs)
{
	struct wbsd_host* host = dev_id;
	int isr;
	
	isr = inb(host->base + WBSD_ISR);

	/*
	 * Was it actually our hardware that caused the interrupt?
	 */
	if (isr == 0xff || isr == 0x00)
		return IRQ_NONE;

	/*
	 * Schedule tasklets as needed.
	 */
	if (isr & WBSD_INT_CARD)
		tasklet_schedule(&host->card_tasklet);
	if (isr & WBSD_INT_FIFO_THRE)
		tasklet_hi_schedule(&host->fifo_tasklet);
	if (isr & WBSD_INT_CRC)
		tasklet_hi_schedule(&host->crc_tasklet);
	if (isr & WBSD_INT_TIMEOUT)
		tasklet_hi_schedule(&host->timeout_tasklet);
	if (isr & WBSD_INT_BUSYEND)
		tasklet_hi_schedule(&host->block_tasklet);
	if (isr & WBSD_INT_TC)
		tasklet_schedule(&host->finish_tasklet);
	
	return IRQ_HANDLED;
}

/*
 * Support functions for probe
 */

static int wbsd_scan(struct wbsd_host* host)
{
	int i, j, k;
	int id;
	
	/*
	 * Iterate through all ports, all codes to
	 * find hardware that is in our known list.
	 */
	for (i = 0;i < sizeof(config_ports)/sizeof(int);i++)
	{
		if (!request_region(config_ports[i], 2, DRIVER_NAME))
			continue;
			
		for (j = 0;j < sizeof(unlock_codes)/sizeof(int);j++)
		{
			id = 0xFFFF;
			
			outb(unlock_codes[j], config_ports[i]);
			outb(unlock_codes[j], config_ports[i]);
			
			outb(WBSD_CONF_ID_HI, config_ports[i]);
			id = inb(config_ports[i] + 1) << 8;

			outb(WBSD_CONF_ID_LO, config_ports[i]);
			id |= inb(config_ports[i] + 1);
			
			for (k = 0;k < sizeof(valid_ids)/sizeof(int);k++)
			{
				if (id == valid_ids[k])
				{				
					host->chip_id = id;
					host->config = config_ports[i];
					host->unlock_code = unlock_codes[i];
				
					return 0;
				}
			}
			
			if (id != 0xFFFF)
			{
				DBG("Unknown hardware (id %x) found at %x\n",
					id, config_ports[i]);
			}

			outb(LOCK_CODE, config_ports[i]);
		}
		
		release_region(config_ports[i], 2);
	}
	
	return -ENODEV;
}

static int wbsd_request_regions(struct wbsd_host* host)
{
	if (io & 0x7)
		return -EINVAL;
	
	if (!request_region(io, 8, DRIVER_NAME))
		return -EIO;
	
	host->base = io;
		
	return 0;
}

static void wbsd_release_regions(struct wbsd_host* host)
{
	if (host->base)
		release_region(host->base, 8);

	if (host->config)
		release_region(host->config, 2);
}

static void wbsd_init_dma(struct wbsd_host* host)
{
	host->dma = -1;
	
	if (dma < 0)
		return;
	
	if (request_dma(dma, DRIVER_NAME))
		goto err;
	
	/*
	 * We need to allocate a special buffer in
	 * order for ISA to be able to DMA to it.
	 */
	host->dma_buffer = kmalloc(65536,
		GFP_NOIO | GFP_DMA | __GFP_REPEAT | __GFP_NOWARN);
	if (!host->dma_buffer)
		goto free;

	/*
	 * Translate the address to a physical address.
	 */
	host->dma_addr = isa_virt_to_bus(host->dma_buffer);
			
	/*
	 * ISA DMA must be aligned on a 64k basis.
	 */
	if ((host->dma_addr & 0xffff) != 0)
		goto kfree;
	/*
	 * ISA cannot access memory above 16 MB.
	 */
	else if (host->dma_addr >= 0x1000000)
		goto kfree;

	host->dma = dma;
	
	return;
	
kfree:
	/*
	 * If we've gotten here then there is some kind of alignment bug
	 */
	BUG_ON(1);
	
	kfree(host->dma_buffer);
	host->dma_buffer = NULL;

free:
	free_dma(dma);

err:
	printk(KERN_WARNING DRIVER_NAME ": Unable to allocate DMA %d. "
		"Falling back on FIFO.\n", dma);
}

static struct mmc_host_ops wbsd_ops = {
	.request	= wbsd_request,
	.set_ios	= wbsd_set_ios,
};

/*
 * Device probe
 */

static int wbsd_probe(struct device* dev)
{
	struct wbsd_host* host = NULL;
	struct mmc_host* mmc = NULL;
	int ret;
	
	/*
	 * Allocate MMC structure.
	 */
	mmc = mmc_alloc_host(sizeof(struct wbsd_host), dev);
	if (!mmc)
		return -ENOMEM;
	
	host = mmc_priv(mmc);
	host->mmc = mmc;
	
	/*
	 * Scan for hardware.
	 */
	ret = wbsd_scan(host);
	if (ret)
		goto freemmc;

	/*
	 * Reset the chip.
	 */	
	wbsd_write_config(host, WBSD_CONF_SWRST, 1);
	wbsd_write_config(host, WBSD_CONF_SWRST, 0);

	/*
	 * Allocate I/O ports.
	 */
	ret = wbsd_request_regions(host);
	if (ret)
		goto release;

	/*
	 * Set host parameters.
	 */
	mmc->ops = &wbsd_ops;
	mmc->f_min = 375000;
	mmc->f_max = 24000000;
	mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34;
	
	spin_lock_init(&host->lock);

	/*
	 * Select SD/MMC function.
	 */
	wbsd_write_config(host, WBSD_CONF_DEVICE, DEVICE_SD);
	
	/*
	 * Set up card detection.
	 */
	wbsd_write_config(host, WBSD_CONF_PINS, 0x02);
	
	/*
	 * Configure I/O port.
	 */
	wbsd_write_config(host, WBSD_CONF_PORT_HI, host->base >> 8);
	wbsd_write_config(host, WBSD_CONF_PORT_LO, host->base & 0xff);

	/*
	 * Allocate interrupt.
	 */
	ret = request_irq(irq, wbsd_irq, SA_SHIRQ, DRIVER_NAME, host);
	if (ret)
		goto release;
	
	host->irq = irq;
	
	/*
	 * Set up tasklets.
	 */
	tasklet_init(&host->card_tasklet, wbsd_tasklet_card, (unsigned long)host);
	tasklet_init(&host->fifo_tasklet, wbsd_tasklet_fifo, (unsigned long)host);
	tasklet_init(&host->crc_tasklet, wbsd_tasklet_crc, (unsigned long)host);
	tasklet_init(&host->timeout_tasklet, wbsd_tasklet_timeout, (unsigned long)host);
	tasklet_init(&host->finish_tasklet, wbsd_tasklet_finish, (unsigned long)host);
	tasklet_init(&host->block_tasklet, wbsd_tasklet_block, (unsigned long)host);
	
	/*
	 * Configure interrupt.
	 */
	wbsd_write_config(host, WBSD_CONF_IRQ, host->irq);
	
	/*
	 * Allocate DMA.
	 */
	wbsd_init_dma(host);
	
	/*
	 * If all went well, then configure DMA.
	 */
	if (host->dma >= 0)
		wbsd_write_config(host, WBSD_CONF_DRQ, host->dma);
	
	/*
	 * Maximum number of segments. Worst case is one sector per segment
	 * so this will be 64kB/512.
	 */
	mmc->max_hw_segs = NR_SG;
	mmc->max_phys_segs = NR_SG;
	
	/*
	 * Maximum number of sectors in one transfer. Also limited by 64kB
	 * buffer.
	 */
	mmc->max_sectors = 128;
	
	/*
	 * Maximum segment size. Could be one segment with the maximum number
	 * of segments.
	 */
	mmc->max_seg_size = mmc->max_sectors * 512;
	
	/*
	 * Enable chip.
	 */
	wbsd_write_config(host, WBSD_CONF_ENABLE, 1);
	
	/*
	 * Power up chip.
	 */
	wbsd_write_config(host, WBSD_CONF_POWER, 0x20);
	
	/*
	 * Power Management stuff. No idea how this works.
	 * Not tested.
	 */
#ifdef CONFIG_PM
	wbsd_write_config(host, WBSD_CONF_PME, 0xA0);
#endif

	/*
	 * Reset the chip into a known state.
	 */
	wbsd_init_device(host);
	
	dev_set_drvdata(dev, mmc);
	
	/*
	 * Add host to MMC layer.
	 */
	mmc_add_host(mmc);

	printk(KERN_INFO "%s: W83L51xD id %x at 0x%x irq %d dma %d\n",
		mmc_hostname(mmc), (int)host->chip_id, (int)host->base,
		(int)host->irq, (int)host->dma);

	return 0;

release:
	wbsd_release_regions(host);

freemmc:
	mmc_free_host(mmc);

	return ret;
}

/*
 * Device remove
 */

static int wbsd_remove(struct device* dev)
{
	struct mmc_host* mmc = dev_get_drvdata(dev);
	struct wbsd_host* host;
	
	if (!mmc)
		return 0;

	host = mmc_priv(mmc);
	
	/*
	 * Unregister host with MMC layer.
	 */
	mmc_remove_host(mmc);

	/*
	 * Power down the SD/MMC function.
	 */
	wbsd_unlock_config(host);
	wbsd_write_config(host, WBSD_CONF_DEVICE, DEVICE_SD);
	wbsd_write_config(host, WBSD_CONF_ENABLE, 0);
	wbsd_lock_config(host);
	
	/*
	 * Free resources.
	 */
	if (host->dma_buffer)
		kfree(host->dma_buffer);
	
	if (host->dma >= 0)
		free_dma(host->dma);

	free_irq(host->irq, host);
	
	tasklet_kill(&host->card_tasklet);
	tasklet_kill(&host->fifo_tasklet);
	tasklet_kill(&host->crc_tasklet);
	tasklet_kill(&host->timeout_tasklet);
	tasklet_kill(&host->finish_tasklet);
	tasklet_kill(&host->block_tasklet);
	
	wbsd_release_regions(host);
	
	mmc_free_host(mmc);

	return 0;
}

/*
 * Power management
 */

#ifdef CONFIG_PM
static int wbsd_suspend(struct device *dev, u32 state, u32 level)
{
	DBGF("Not yet supported\n");

	return 0;
}

static int wbsd_resume(struct device *dev, u32 level)
{
	DBGF("Not yet supported\n");

	return 0;
}
#else
#define wbsd_suspend NULL
#define wbsd_resume NULL
#endif

static void wbsd_release(struct device *dev)
{
}

static struct platform_device wbsd_device = {
	.name		= DRIVER_NAME,
	.id			= -1,
	.dev		= {
		.release = wbsd_release,
	},
};

static struct device_driver wbsd_driver = {
	.name		= DRIVER_NAME,
	.bus		= &platform_bus_type,
	.probe		= wbsd_probe,
	.remove		= wbsd_remove,
	
	.suspend	= wbsd_suspend,
	.resume		= wbsd_resume,
};

/*
 * Module loading/unloading
 */

static int __init wbsd_drv_init(void)
{
	int result;
	
	printk(KERN_INFO DRIVER_NAME
		": Winbond W83L51xD SD/MMC card interface driver, "
		DRIVER_VERSION "\n");
	printk(KERN_INFO DRIVER_NAME ": Copyright(c) Pierre Ossman\n");
	
	result = driver_register(&wbsd_driver);
	if (result < 0)
		return result;

	result = platform_device_register(&wbsd_device);
	if (result < 0)
		return result;

	return 0;
}

static void __exit wbsd_drv_exit(void)
{
	platform_device_unregister(&wbsd_device);
	
	driver_unregister(&wbsd_driver);

	DBG("unloaded\n");
}

module_init(wbsd_drv_init);
module_exit(wbsd_drv_exit);
module_param(io, uint, 0444);
module_param(irq, uint, 0444);
module_param(dma, int, 0444);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Winbond W83L51xD SD/MMC card interface driver");

MODULE_PARM_DESC(io, "I/O base to allocate. Must be 8 byte aligned. (default 0x248)");
MODULE_PARM_DESC(irq, "IRQ to allocate. (default 6)");
MODULE_PARM_DESC(dma, "DMA channel to allocate. -1 for no DMA. (default 2)");