diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-at91.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-at91.c | 850 |
1 files changed, 0 insertions, 850 deletions
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c deleted file mode 100644 index 6bb839b688be..000000000000 --- a/drivers/i2c/busses/i2c-at91.c +++ /dev/null @@ -1,850 +0,0 @@ -/* - * i2c Support for Atmel's AT91 Two-Wire Interface (TWI) - * - * Copyright (C) 2011 Weinmann Medical GmbH - * Author: Nikolaus Voss <n.voss@weinmann.de> - * - * Evolved from original work by: - * Copyright (C) 2004 Rick Bronson - * Converted to 2.6 by Andrew Victor <andrew@sanpeople.com> - * - * Borrowed heavily from original work by: - * Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com> - * - * 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/clk.h> -#include <linux/completion.h> -#include <linux/dma-mapping.h> -#include <linux/dmaengine.h> -#include <linux/err.h> -#include <linux/i2c.h> -#include <linux/interrupt.h> -#include <linux/io.h> -#include <linux/module.h> -#include <linux/of.h> -#include <linux/of_device.h> -#include <linux/of_i2c.h> -#include <linux/platform_device.h> -#include <linux/slab.h> -#include <linux/platform_data/dma-atmel.h> - -#define TWI_CLK_HZ 100000 /* max 400 Kbits/s */ -#define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */ -#define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */ - -/* AT91 TWI register definitions */ -#define AT91_TWI_CR 0x0000 /* Control Register */ -#define AT91_TWI_START 0x0001 /* Send a Start Condition */ -#define AT91_TWI_STOP 0x0002 /* Send a Stop Condition */ -#define AT91_TWI_MSEN 0x0004 /* Master Transfer Enable */ -#define AT91_TWI_SVDIS 0x0020 /* Slave Transfer Disable */ -#define AT91_TWI_QUICK 0x0040 /* SMBus quick command */ -#define AT91_TWI_SWRST 0x0080 /* Software Reset */ - -#define AT91_TWI_MMR 0x0004 /* Master Mode Register */ -#define AT91_TWI_IADRSZ_1 0x0100 /* Internal Device Address Size */ -#define AT91_TWI_MREAD 0x1000 /* Master Read Direction */ - -#define AT91_TWI_IADR 0x000c /* Internal Address Register */ - -#define AT91_TWI_CWGR 0x0010 /* Clock Waveform Generator Reg */ - -#define AT91_TWI_SR 0x0020 /* Status Register */ -#define AT91_TWI_TXCOMP 0x0001 /* Transmission Complete */ -#define AT91_TWI_RXRDY 0x0002 /* Receive Holding Register Ready */ -#define AT91_TWI_TXRDY 0x0004 /* Transmit Holding Register Ready */ - -#define AT91_TWI_OVRE 0x0040 /* Overrun Error */ -#define AT91_TWI_UNRE 0x0080 /* Underrun Error */ -#define AT91_TWI_NACK 0x0100 /* Not Acknowledged */ - -#define AT91_TWI_IER 0x0024 /* Interrupt Enable Register */ -#define AT91_TWI_IDR 0x0028 /* Interrupt Disable Register */ -#define AT91_TWI_IMR 0x002c /* Interrupt Mask Register */ -#define AT91_TWI_RHR 0x0030 /* Receive Holding Register */ -#define AT91_TWI_THR 0x0034 /* Transmit Holding Register */ - -struct at91_twi_pdata { - unsigned clk_max_div; - unsigned clk_offset; - bool has_unre_flag; - bool has_dma_support; - struct at_dma_slave dma_slave; -}; - -struct at91_twi_dma { - struct dma_chan *chan_rx; - struct dma_chan *chan_tx; - struct scatterlist sg; - struct dma_async_tx_descriptor *data_desc; - enum dma_data_direction direction; - bool buf_mapped; - bool xfer_in_progress; -}; - -struct at91_twi_dev { - struct device *dev; - void __iomem *base; - struct completion cmd_complete; - struct clk *clk; - u8 *buf; - size_t buf_len; - struct i2c_msg *msg; - int irq; - unsigned imr; - unsigned transfer_status; - struct i2c_adapter adapter; - unsigned twi_cwgr_reg; - struct at91_twi_pdata *pdata; - bool use_dma; - struct at91_twi_dma dma; -}; - -static unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg) -{ - return readl_relaxed(dev->base + reg); -} - -static void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) -{ - writel_relaxed(val, dev->base + reg); -} - -static void at91_disable_twi_interrupts(struct at91_twi_dev *dev) -{ - at91_twi_write(dev, AT91_TWI_IDR, - AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY); -} - -static void at91_twi_irq_save(struct at91_twi_dev *dev) -{ - dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & 0x7; - at91_disable_twi_interrupts(dev); -} - -static void at91_twi_irq_restore(struct at91_twi_dev *dev) -{ - at91_twi_write(dev, AT91_TWI_IER, dev->imr); -} - -static void at91_init_twi_bus(struct at91_twi_dev *dev) -{ - at91_disable_twi_interrupts(dev); - at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST); - at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN); - at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS); - at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg); -} - -/* - * Calculate symmetric clock as stated in datasheet: - * twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset)) - */ -static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk) -{ - int ckdiv, cdiv, div; - struct at91_twi_pdata *pdata = dev->pdata; - int offset = pdata->clk_offset; - int max_ckdiv = pdata->clk_max_div; - - div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk), - 2 * twi_clk) - offset); - ckdiv = fls(div >> 8); - cdiv = div >> ckdiv; - - if (ckdiv > max_ckdiv) { - dev_warn(dev->dev, "%d exceeds ckdiv max value which is %d.\n", - ckdiv, max_ckdiv); - ckdiv = max_ckdiv; - cdiv = 255; - } - - dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv; - dev_dbg(dev->dev, "cdiv %d ckdiv %d\n", cdiv, ckdiv); -} - -static void at91_twi_dma_cleanup(struct at91_twi_dev *dev) -{ - struct at91_twi_dma *dma = &dev->dma; - - at91_twi_irq_save(dev); - - if (dma->xfer_in_progress) { - if (dma->direction == DMA_FROM_DEVICE) - dmaengine_terminate_all(dma->chan_rx); - else - dmaengine_terminate_all(dma->chan_tx); - dma->xfer_in_progress = false; - } - if (dma->buf_mapped) { - dma_unmap_single(dev->dev, sg_dma_address(&dma->sg), - dev->buf_len, dma->direction); - dma->buf_mapped = false; - } - - at91_twi_irq_restore(dev); -} - -static void at91_twi_write_next_byte(struct at91_twi_dev *dev) -{ - if (dev->buf_len <= 0) - return; - - at91_twi_write(dev, AT91_TWI_THR, *dev->buf); - - /* send stop when last byte has been written */ - if (--dev->buf_len == 0) - at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); - - dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len); - - ++dev->buf; -} - -static void at91_twi_write_data_dma_callback(void *data) -{ - struct at91_twi_dev *dev = (struct at91_twi_dev *)data; - - dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg), - dev->buf_len, DMA_MEM_TO_DEV); - - at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); -} - -static void at91_twi_write_data_dma(struct at91_twi_dev *dev) -{ - dma_addr_t dma_addr; - struct dma_async_tx_descriptor *txdesc; - struct at91_twi_dma *dma = &dev->dma; - struct dma_chan *chan_tx = dma->chan_tx; - - if (dev->buf_len <= 0) - return; - - dma->direction = DMA_TO_DEVICE; - - at91_twi_irq_save(dev); - dma_addr = dma_map_single(dev->dev, dev->buf, dev->buf_len, - DMA_TO_DEVICE); - if (dma_mapping_error(dev->dev, dma_addr)) { - dev_err(dev->dev, "dma map failed\n"); - return; - } - dma->buf_mapped = true; - at91_twi_irq_restore(dev); - sg_dma_len(&dma->sg) = dev->buf_len; - sg_dma_address(&dma->sg) = dma_addr; - - txdesc = dmaengine_prep_slave_sg(chan_tx, &dma->sg, 1, DMA_MEM_TO_DEV, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!txdesc) { - dev_err(dev->dev, "dma prep slave sg failed\n"); - goto error; - } - - txdesc->callback = at91_twi_write_data_dma_callback; - txdesc->callback_param = dev; - - dma->xfer_in_progress = true; - dmaengine_submit(txdesc); - dma_async_issue_pending(chan_tx); - - return; - -error: - at91_twi_dma_cleanup(dev); -} - -static void at91_twi_read_next_byte(struct at91_twi_dev *dev) -{ - if (dev->buf_len <= 0) - return; - - *dev->buf = at91_twi_read(dev, AT91_TWI_RHR) & 0xff; - --dev->buf_len; - - /* handle I2C_SMBUS_BLOCK_DATA */ - if (unlikely(dev->msg->flags & I2C_M_RECV_LEN)) { - dev->msg->flags &= ~I2C_M_RECV_LEN; - dev->buf_len += *dev->buf; - dev->msg->len = dev->buf_len + 1; - dev_dbg(dev->dev, "received block length %d\n", dev->buf_len); - } - - /* send stop if second but last byte has been read */ - if (dev->buf_len == 1) - at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP); - - dev_dbg(dev->dev, "read 0x%x, to go %d\n", *dev->buf, dev->buf_len); - - ++dev->buf; -} - -static void at91_twi_read_data_dma_callback(void *data) -{ - struct at91_twi_dev *dev = (struct at91_twi_dev *)data; - - dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg), - dev->buf_len, DMA_DEV_TO_MEM); - - /* The last two bytes have to be read without using dma */ - dev->buf += dev->buf_len - 2; - dev->buf_len = 2; - at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_RXRDY); -} - -static void at91_twi_read_data_dma(struct at91_twi_dev *dev) -{ - dma_addr_t dma_addr; - struct dma_async_tx_descriptor *rxdesc; - struct at91_twi_dma *dma = &dev->dma; - struct dma_chan *chan_rx = dma->chan_rx; - - dma->direction = DMA_FROM_DEVICE; - - /* Keep in mind that we won't use dma to read the last two bytes */ - at91_twi_irq_save(dev); - dma_addr = dma_map_single(dev->dev, dev->buf, dev->buf_len - 2, - DMA_FROM_DEVICE); - if (dma_mapping_error(dev->dev, dma_addr)) { - dev_err(dev->dev, "dma map failed\n"); - return; - } - dma->buf_mapped = true; - at91_twi_irq_restore(dev); - dma->sg.dma_address = dma_addr; - sg_dma_len(&dma->sg) = dev->buf_len - 2; - - rxdesc = dmaengine_prep_slave_sg(chan_rx, &dma->sg, 1, DMA_DEV_TO_MEM, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!rxdesc) { - dev_err(dev->dev, "dma prep slave sg failed\n"); - goto error; - } - - rxdesc->callback = at91_twi_read_data_dma_callback; - rxdesc->callback_param = dev; - - dma->xfer_in_progress = true; - dmaengine_submit(rxdesc); - dma_async_issue_pending(dma->chan_rx); - - return; - -error: - at91_twi_dma_cleanup(dev); -} - -static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id) -{ - struct at91_twi_dev *dev = dev_id; - const unsigned status = at91_twi_read(dev, AT91_TWI_SR); - const unsigned irqstatus = status & at91_twi_read(dev, AT91_TWI_IMR); - - if (!irqstatus) - return IRQ_NONE; - else if (irqstatus & AT91_TWI_RXRDY) - at91_twi_read_next_byte(dev); - else if (irqstatus & AT91_TWI_TXRDY) - at91_twi_write_next_byte(dev); - - /* catch error flags */ - dev->transfer_status |= status; - - if (irqstatus & AT91_TWI_TXCOMP) { - at91_disable_twi_interrupts(dev); - complete(&dev->cmd_complete); - } - - return IRQ_HANDLED; -} - -static int at91_do_twi_transfer(struct at91_twi_dev *dev) -{ - int ret; - bool has_unre_flag = dev->pdata->has_unre_flag; - - dev_dbg(dev->dev, "transfer: %s %d bytes.\n", - (dev->msg->flags & I2C_M_RD) ? "read" : "write", dev->buf_len); - - INIT_COMPLETION(dev->cmd_complete); - dev->transfer_status = 0; - - if (!dev->buf_len) { - at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_QUICK); - at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP); - } else if (dev->msg->flags & I2C_M_RD) { - unsigned start_flags = AT91_TWI_START; - - if (at91_twi_read(dev, AT91_TWI_SR) & AT91_TWI_RXRDY) { - dev_err(dev->dev, "RXRDY still set!"); - at91_twi_read(dev, AT91_TWI_RHR); - } - - /* if only one byte is to be read, immediately stop transfer */ - if (dev->buf_len <= 1 && !(dev->msg->flags & I2C_M_RECV_LEN)) - start_flags |= AT91_TWI_STOP; - at91_twi_write(dev, AT91_TWI_CR, start_flags); - /* - * When using dma, the last byte has to be read manually in - * order to not send the stop command too late and then - * to receive extra data. In practice, there are some issues - * if you use the dma to read n-1 bytes because of latency. - * Reading n-2 bytes with dma and the two last ones manually - * seems to be the best solution. - */ - if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) { - at91_twi_read_data_dma(dev); - /* - * It is important to enable TXCOMP irq here because - * doing it only when transferring the last two bytes - * will mask NACK errors since TXCOMP is set when a - * NACK occurs. - */ - at91_twi_write(dev, AT91_TWI_IER, - AT91_TWI_TXCOMP); - } else - at91_twi_write(dev, AT91_TWI_IER, - AT91_TWI_TXCOMP | AT91_TWI_RXRDY); - } else { - if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) { - at91_twi_write_data_dma(dev); - at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP); - } else { - at91_twi_write_next_byte(dev); - at91_twi_write(dev, AT91_TWI_IER, - AT91_TWI_TXCOMP | AT91_TWI_TXRDY); - } - } - - ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, - dev->adapter.timeout); - if (ret == 0) { - dev_err(dev->dev, "controller timed out\n"); - at91_init_twi_bus(dev); - ret = -ETIMEDOUT; - goto error; - } - if (dev->transfer_status & AT91_TWI_NACK) { - dev_dbg(dev->dev, "received nack\n"); - ret = -EREMOTEIO; - goto error; - } - if (dev->transfer_status & AT91_TWI_OVRE) { - dev_err(dev->dev, "overrun while reading\n"); - ret = -EIO; - goto error; - } - if (has_unre_flag && dev->transfer_status & AT91_TWI_UNRE) { - dev_err(dev->dev, "underrun while writing\n"); - ret = -EIO; - goto error; - } - dev_dbg(dev->dev, "transfer complete\n"); - - return 0; - -error: - at91_twi_dma_cleanup(dev); - return ret; -} - -static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) -{ - struct at91_twi_dev *dev = i2c_get_adapdata(adap); - int ret; - unsigned int_addr_flag = 0; - struct i2c_msg *m_start = msg; - - dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num); - - /* - * The hardware can handle at most two messages concatenated by a - * repeated start via it's internal address feature. - */ - if (num > 2) { - dev_err(dev->dev, - "cannot handle more than two concatenated messages.\n"); - return 0; - } else if (num == 2) { - int internal_address = 0; - int i; - - if (msg->flags & I2C_M_RD) { - dev_err(dev->dev, "first transfer must be write.\n"); - return -EINVAL; - } - if (msg->len > 3) { - dev_err(dev->dev, "first message size must be <= 3.\n"); - return -EINVAL; - } - - /* 1st msg is put into the internal address, start with 2nd */ - m_start = &msg[1]; - for (i = 0; i < msg->len; ++i) { - const unsigned addr = msg->buf[msg->len - 1 - i]; - - internal_address |= addr << (8 * i); - int_addr_flag += AT91_TWI_IADRSZ_1; - } - at91_twi_write(dev, AT91_TWI_IADR, internal_address); - } - - at91_twi_write(dev, AT91_TWI_MMR, (m_start->addr << 16) | int_addr_flag - | ((m_start->flags & I2C_M_RD) ? AT91_TWI_MREAD : 0)); - - dev->buf_len = m_start->len; - dev->buf = m_start->buf; - dev->msg = m_start; - - ret = at91_do_twi_transfer(dev); - - return (ret < 0) ? ret : num; -} - -static u32 at91_twi_func(struct i2c_adapter *adapter) -{ - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL - | I2C_FUNC_SMBUS_READ_BLOCK_DATA; -} - -static struct i2c_algorithm at91_twi_algorithm = { - .master_xfer = at91_twi_xfer, - .functionality = at91_twi_func, -}; - -static struct at91_twi_pdata at91rm9200_config = { - .clk_max_div = 5, - .clk_offset = 3, - .has_unre_flag = true, - .has_dma_support = false, -}; - -static struct at91_twi_pdata at91sam9261_config = { - .clk_max_div = 5, - .clk_offset = 4, - .has_unre_flag = false, - .has_dma_support = false, -}; - -static struct at91_twi_pdata at91sam9260_config = { - .clk_max_div = 7, - .clk_offset = 4, - .has_unre_flag = false, - .has_dma_support = false, -}; - -static struct at91_twi_pdata at91sam9g20_config = { - .clk_max_div = 7, - .clk_offset = 4, - .has_unre_flag = false, - .has_dma_support = false, -}; - -static struct at91_twi_pdata at91sam9g10_config = { - .clk_max_div = 7, - .clk_offset = 4, - .has_unre_flag = false, - .has_dma_support = false, -}; - -static const struct platform_device_id at91_twi_devtypes[] = { - { - .name = "i2c-at91rm9200", - .driver_data = (unsigned long) &at91rm9200_config, - }, { - .name = "i2c-at91sam9261", - .driver_data = (unsigned long) &at91sam9261_config, - }, { - .name = "i2c-at91sam9260", - .driver_data = (unsigned long) &at91sam9260_config, - }, { - .name = "i2c-at91sam9g20", - .driver_data = (unsigned long) &at91sam9g20_config, - }, { - .name = "i2c-at91sam9g10", - .driver_data = (unsigned long) &at91sam9g10_config, - }, { - /* sentinel */ - } -}; - -#if defined(CONFIG_OF) -static struct at91_twi_pdata at91sam9x5_config = { - .clk_max_div = 7, - .clk_offset = 4, - .has_unre_flag = false, - .has_dma_support = true, -}; - -static const struct of_device_id atmel_twi_dt_ids[] = { - { - .compatible = "atmel,at91rm9200-i2c", - .data = &at91rm9200_config, - } , { - .compatible = "atmel,at91sam9260-i2c", - .data = &at91sam9260_config, - } , { - .compatible = "atmel,at91sam9g20-i2c", - .data = &at91sam9g20_config, - } , { - .compatible = "atmel,at91sam9g10-i2c", - .data = &at91sam9g10_config, - }, { - .compatible = "atmel,at91sam9x5-i2c", - .data = &at91sam9x5_config, - }, { - /* sentinel */ - } -}; -MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids); -#endif - -static bool filter(struct dma_chan *chan, void *pdata) -{ - struct at91_twi_pdata *sl_pdata = pdata; - struct at_dma_slave *sl; - - if (!sl_pdata) - return false; - - sl = &sl_pdata->dma_slave; - if (sl && (sl->dma_dev == chan->device->dev)) { - chan->private = sl; - return true; - } else { - return false; - } -} - -static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) -{ - int ret = 0; - struct at91_twi_pdata *pdata = dev->pdata; - struct dma_slave_config slave_config; - struct at91_twi_dma *dma = &dev->dma; - dma_cap_mask_t mask; - - memset(&slave_config, 0, sizeof(slave_config)); - slave_config.src_addr = (dma_addr_t)phy_addr + AT91_TWI_RHR; - slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; - slave_config.src_maxburst = 1; - slave_config.dst_addr = (dma_addr_t)phy_addr + AT91_TWI_THR; - slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; - slave_config.dst_maxburst = 1; - slave_config.device_fc = false; - - dma_cap_zero(mask); - dma_cap_set(DMA_SLAVE, mask); - - dma->chan_tx = dma_request_slave_channel_compat(mask, filter, pdata, - dev->dev, "tx"); - if (!dma->chan_tx) { - dev_err(dev->dev, "can't get a DMA channel for tx\n"); - ret = -EBUSY; - goto error; - } - - dma->chan_rx = dma_request_slave_channel_compat(mask, filter, pdata, - dev->dev, "rx"); - if (!dma->chan_rx) { - dev_err(dev->dev, "can't get a DMA channel for rx\n"); - ret = -EBUSY; - goto error; - } - - slave_config.direction = DMA_MEM_TO_DEV; - if (dmaengine_slave_config(dma->chan_tx, &slave_config)) { - dev_err(dev->dev, "failed to configure tx channel\n"); - ret = -EINVAL; - goto error; - } - - slave_config.direction = DMA_DEV_TO_MEM; - if (dmaengine_slave_config(dma->chan_rx, &slave_config)) { - dev_err(dev->dev, "failed to configure rx channel\n"); - ret = -EINVAL; - goto error; - } - - sg_init_table(&dma->sg, 1); - dma->buf_mapped = false; - dma->xfer_in_progress = false; - - dev_info(dev->dev, "using %s (tx) and %s (rx) for DMA transfers\n", - dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); - - return ret; - -error: - dev_info(dev->dev, "can't use DMA\n"); - if (dma->chan_rx) - dma_release_channel(dma->chan_rx); - if (dma->chan_tx) - dma_release_channel(dma->chan_tx); - return ret; -} - -static struct at91_twi_pdata *at91_twi_get_driver_data( - struct platform_device *pdev) -{ - if (pdev->dev.of_node) { - const struct of_device_id *match; - match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node); - if (!match) - return NULL; - return (struct at91_twi_pdata *)match->data; - } - return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data; -} - -static int at91_twi_probe(struct platform_device *pdev) -{ - struct at91_twi_dev *dev; - struct resource *mem; - int rc; - u32 phy_addr; - - dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); - if (!dev) - return -ENOMEM; - init_completion(&dev->cmd_complete); - dev->dev = &pdev->dev; - - mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!mem) - return -ENODEV; - phy_addr = mem->start; - - dev->pdata = at91_twi_get_driver_data(pdev); - if (!dev->pdata) - return -ENODEV; - - dev->base = devm_ioremap_resource(&pdev->dev, mem); - if (IS_ERR(dev->base)) - return PTR_ERR(dev->base); - - dev->irq = platform_get_irq(pdev, 0); - if (dev->irq < 0) - return dev->irq; - - rc = devm_request_irq(&pdev->dev, dev->irq, atmel_twi_interrupt, 0, - dev_name(dev->dev), dev); - if (rc) { - dev_err(dev->dev, "Cannot get irq %d: %d\n", dev->irq, rc); - return rc; - } - - platform_set_drvdata(pdev, dev); - - dev->clk = devm_clk_get(dev->dev, NULL); - if (IS_ERR(dev->clk)) { - dev_err(dev->dev, "no clock defined\n"); - return -ENODEV; - } - clk_prepare_enable(dev->clk); - - if (dev->pdata->has_dma_support) { - if (at91_twi_configure_dma(dev, phy_addr) == 0) - dev->use_dma = true; - } - - at91_calc_twi_clock(dev, TWI_CLK_HZ); - at91_init_twi_bus(dev); - - snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); - i2c_set_adapdata(&dev->adapter, dev); - dev->adapter.owner = THIS_MODULE; - dev->adapter.class = I2C_CLASS_HWMON; - dev->adapter.algo = &at91_twi_algorithm; - dev->adapter.dev.parent = dev->dev; - dev->adapter.nr = pdev->id; - dev->adapter.timeout = AT91_I2C_TIMEOUT; - dev->adapter.dev.of_node = pdev->dev.of_node; - - rc = i2c_add_numbered_adapter(&dev->adapter); - if (rc) { - dev_err(dev->dev, "Adapter %s registration failed\n", - dev->adapter.name); - clk_disable_unprepare(dev->clk); - return rc; - } - - of_i2c_register_devices(&dev->adapter); - - dev_info(dev->dev, "AT91 i2c bus driver.\n"); - return 0; -} - -static int at91_twi_remove(struct platform_device *pdev) -{ - struct at91_twi_dev *dev = platform_get_drvdata(pdev); - - i2c_del_adapter(&dev->adapter); - clk_disable_unprepare(dev->clk); - - return 0; -} - -#ifdef CONFIG_PM - -static int at91_twi_runtime_suspend(struct device *dev) -{ - struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); - - clk_disable(twi_dev->clk); - - return 0; -} - -static int at91_twi_runtime_resume(struct device *dev) -{ - struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); - - return clk_enable(twi_dev->clk); -} - -static const struct dev_pm_ops at91_twi_pm = { - .runtime_suspend = at91_twi_runtime_suspend, - .runtime_resume = at91_twi_runtime_resume, -}; - -#define at91_twi_pm_ops (&at91_twi_pm) -#else -#define at91_twi_pm_ops NULL -#endif - -static struct platform_driver at91_twi_driver = { - .probe = at91_twi_probe, - .remove = at91_twi_remove, - .id_table = at91_twi_devtypes, - .driver = { - .name = "at91_i2c", - .owner = THIS_MODULE, - .of_match_table = of_match_ptr(atmel_twi_dt_ids), - .pm = at91_twi_pm_ops, - }, -}; - -static int __init at91_twi_init(void) -{ - return platform_driver_register(&at91_twi_driver); -} - -static void __exit at91_twi_exit(void) -{ - platform_driver_unregister(&at91_twi_driver); -} - -subsys_initcall(at91_twi_init); -module_exit(at91_twi_exit); - -MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>"); -MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:at91_i2c"); |