On Wed, Jun 03, 2009 at 11:59:15PM +0400, dmitry pervushin wrote: > Hello Ben & i2c people, > > Here is the patch to support I2C bus on Freescale STMP378x platform; any > comments are welcome > > Signed-off-by: Dmitrij Frasenyak <d.frasenyak@xxxxxxxxxxxxxxxxx> should really have a from Dmitrij Frasenyak line as he is the original authour and you're just pushing it, IIRC. > Signed-off-by: dmitry pervishin <dpervushin@xxxxxxxxxxxxxxxxx> > > --- > drivers/i2c/busses/Kconfig | 7 > drivers/i2c/busses/Makefile | 1 > drivers/i2c/busses/i2c-stmp378x.c | 440 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 448 insertions(+) > > Index: linux-2.6-arm/drivers/i2c/busses/Kconfig > =================================================================== > --- linux-2.6-arm.orig/drivers/i2c/busses/Kconfig > +++ linux-2.6-arm/drivers/i2c/busses/Kconfig > @@ -513,6 +513,13 @@ config I2C_SIMTEC > This driver can also be built as a module. If so, the module > will be called i2c-simtec. > > +config I2C_STMP378X > + tristate "STMP378x I2C adapter" > + depends on ARCH_STMP378X > + help > + Include support of I2C adapter on Freescale STMP378x board; to build > + the driver as a module, say M here - module will be called i2c-stmp378x. > + > config I2C_VERSATILE > tristate "ARM Versatile/Realview I2C bus support" > depends on ARCH_VERSATILE || ARCH_REALVIEW > Index: linux-2.6-arm/drivers/i2c/busses/Makefile > =================================================================== > --- linux-2.6-arm.orig/drivers/i2c/busses/Makefile > +++ linux-2.6-arm/drivers/i2c/busses/Makefile > @@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_S6000) += i2c-s6000.o > obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o > obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o > obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o > +obj-$(CONFIG_I2C_STMP378X) += i2c-stmp378x.o > obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o > > # External I2C/SMBus adapter drivers > Index: linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c > =================================================================== > --- /dev/null > +++ linux-2.6-arm/drivers/i2c/busses/i2c-stmp378x.c > @@ -0,0 +1,440 @@ > +/* > + * Freescale STMP378X I2C bus driver > + * > + * Author: Dmitrij Frasenyak <sed@xxxxxxxxxxxxxxxxx> > + * > + * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved. > + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. > + */ > + > +/* > + * The code contained herein is licensed under the GNU General Public > + * License. You may obtain a copy of the GNU General Public License > + * Version 2 or later at the following locations: > + * > + * http://www.opensource.org/licenses/gpl-license.html > + * http://www.gnu.org/copyleft/gpl.html > + */ > +#include <linux/module.h> > +#include <linux/delay.h> > +#include <linux/i2c.h> > +#include <linux/err.h> > +#include <linux/interrupt.h> > +#include <linux/completion.h> > +#include <linux/platform_device.h> > +#include <linux/clk.h> > +#include <linux/io.h> > +#include <linux/dma-mapping.h> > + > +#include <mach/platform.h> > +#include <mach/stmp3xxx.h> > +#include <mach/dma.h> > +#include <mach/regs-i2c.h> > +#include <mach/regs-apbx.h> > + > +static const u32 I2C_READ = 1, > + I2C_WRITE = 0; do you really want to be defining things with a prefix of I2C, that might end up clashing with the i2c core? > +static const struct stmp3xxx_dma_command cmd_i2c_select = { > + .cmd = BF(1, APBX_CHn_CMD_XFER_COUNT) | > + BF(1, APBX_CHn_CMD_CMDWORDS) | > + BM_APBX_CHn_CMD_WAIT4ENDCMD | > + BM_APBX_CHn_CMD_CHAIN | > + BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND), what is BF() ? > + .pio_words = { > + [0] = BM_I2C_CTRL0_RETAIN_CLOCK | > + BM_I2C_CTRL0_PRE_SEND_START | > + BM_I2C_CTRL0_MASTER_MODE | > + BM_I2C_CTRL0_DIRECTION | > + BF(1, I2C_CTRL0_XFER_COUNT), > + }, > +}; > + > +static const struct stmp3xxx_dma_command cmd_i2c_write = { > + .cmd = BM_APBX_CHn_CMD_SEMAPHORE | > + BF(1, APBX_CHn_CMD_CMDWORDS) | > + BM_APBX_CHn_CMD_WAIT4ENDCMD | > + BM_APBX_CHn_CMD_IRQONCMPLT | > + BF(BV_APBX_CHn_CMD_COMMAND__DMA_READ, APBX_CHn_CMD_COMMAND), > + .pio_words = { > + [0] = BM_I2C_CTRL0_PRE_SEND_START | > + BM_I2C_CTRL0_MASTER_MODE | > + BM_I2C_CTRL0_DIRECTION, > + }, > +}; > + > +static const struct stmp3xxx_dma_command cmd_i2c_read = { > + .cmd = BM_APBX_CHn_CMD_SEMAPHORE | > + BF(1, APBX_CHn_CMD_CMDWORDS) | > + BM_APBX_CHn_CMD_WAIT4ENDCMD | > + BM_APBX_CHn_CMD_IRQONCMPLT | > + BF(BV_APBX_CHn_CMD_COMMAND__DMA_WRITE, APBX_CHn_CMD_COMMAND), > + .pio_words = { > + [0] = BM_I2C_CTRL0_SEND_NAK_ON_LAST | > + BM_I2C_CTRL0_MASTER_MODE, > + }, > +}; > + > +struct stmp378x_i2c_dev { > + struct device *dev; > + int irq; > + struct completion cmd_complete; > + u32 cmd_err; > + struct i2c_adapter adapter; > + void __iomem *io; > + unsigned dma; > + > + dma_addr_t bufp; > + unsigned char *bufv; > + > + struct stmp3xxx_dma_descriptor i2c_dma_read[2], > + i2c_dma_write; > +}; would be nice to see some kerneldoc descriptions for the fields in this structure. > +static int stmp378x_i2c_init(struct stmp378x_i2c_dev *dev) > +{ > + int err; > + > + err = stmp3xxx_dma_request(dev->dma, dev->dev, dev_name(dev->dev)); > + if (err) > + goto out; > + stmp3xxx_reset_block(dev->io, true); > + > + dev->bufv = dma_alloc_coherent(dev->dev, PAGE_SIZE, > + &dev->bufp, GFP_KERNEL); > + if (dma_mapping_error(dev->dev, dev->bufp)) > + goto out_dma; hmm, doesn't dma_alloc_coherent() fail with an NULL buffer return? > + err = stmp3xxx_request_pin_group(dev->dev->platform_data, > + dev_name(dev->dev)); > + if (err) > + goto out_free; > + > + err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[0]); > + if (err) > + goto out_rd0; > + err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_read[1]); > + if (err) > + goto out_rd1; > + err = stmp3xxx_dma_allocate_command(dev->dma, &dev->i2c_dma_write); > + if (err) > + goto out_wr; > + > + stmp3xxx_dma_reset_channel(dev->dma); > + stmp3xxx_dma_clear_interrupt(dev->dma); > + stmp3xxx_dma_enable_interrupt(dev->dma); > + > + return 0; > +/* > + stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write); > +*/ > +out_wr: > + stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]); > +out_rd1: > + stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]); > +out_rd0: > + stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev)); > +out_free: > + dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp); > +out_dma: > + stmp3xxx_dma_release(dev->dma); > +out: > + return err; > +} > + > +static void stmp378x_i2c_release(struct stmp378x_i2c_dev *dev) > +{ > + stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_write); > + stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[1]); > + stmp3xxx_dma_free_command(dev->dma, &dev->i2c_dma_read[0]); > + dma_free_coherent(dev->dev, PAGE_SIZE, dev->bufv, dev->bufp); > + stmp3xxx_release_pin_group(dev->dev->platform_data, dev_name(dev->dev)); > + stmp3xxx_dma_release(dev->dma); > +} > +/* > + * Low level master read/write transaction. > + */ > +static int stmp378x_i2c_xfer_msg(struct i2c_adapter *adap, > + struct i2c_msg *msg, int stop) > +{ > + struct stmp378x_i2c_dev *dev = i2c_get_adapdata(adap); > + int err; > + struct stmp3xxx_dma_descriptor *c, *r; > + > + init_completion(&dev->cmd_complete); > + dev->cmd_err = 0; > + > + dev_dbg(dev->dev, "start XFER\n"); > + dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", > + msg->addr, msg->len, msg->flags, stop); > + > + if ((msg->len == 0) || (msg->len > (PAGE_SIZE - 1))) > + return -EINVAL; > + > + if (msg->flags & I2C_M_RD) { > + > + c = &dev->i2c_dma_read[0]; > + r = &dev->i2c_dma_read[1]; > + > + /* first, setup the SELECT command */ > + memcpy(c->command, &cmd_i2c_select, sizeof(cmd_i2c_select)); > + c->command->buf_ptr = dev->bufp; > + dev->bufv[0] = msg->addr | I2C_READ; > + > + /* then, setup the READ command */ > + memcpy(r->command, &cmd_i2c_read, sizeof(cmd_i2c_read)); > + r->command->cmd |= BF(msg->len, APBX_CHn_CMD_XFER_COUNT); > + r->command->pio_words[0] |= BF(msg->len, I2C_CTRL0_XFER_COUNT); > + if (stop) > + r->command->pio_words[0] |= BM_I2C_CTRL0_POST_SEND_STOP; > + /* > + * yes, STMP controller can DMA transfer the data from any > + * byte boundary > + */ > + r->command->buf_ptr = dev->bufp + 1; > + > + /* and chain them together */ > + c->command->next = r->handle; > + > + } else { > + > + c = &dev->i2c_dma_write; > + memcpy(c->command, &cmd_i2c_write, sizeof(cmd_i2c_write)); > + c->command->cmd |= BF(msg->len + 1, APBX_CHn_CMD_XFER_COUNT); > + c->command->pio_words[0] |= > + BF(msg->len + 1, I2C_CTRL0_XFER_COUNT); > + if (stop) > + c->command->pio_words[0] |= > + BM_I2C_CTRL0_POST_SEND_STOP; > + dev->bufv[0] = msg->addr | I2C_WRITE; > + memcpy(dev->bufv + 1, msg->buf, msg->len); > + } > + > + stmp3xxx_dma_go(dev->dma, c, 1); > + > + err = wait_for_completion_interruptible_timeout(&dev->cmd_complete, > + msecs_to_jiffies(1000)); > + > + if (err < 0) { > + dev_dbg(dev->dev, "controler is timed out\n"); > + return -ETIMEDOUT; > + } > + if (!dev->cmd_err && (msg->flags & I2C_M_RD)) > + memcpy(msg->buf, dev->bufv + 1, msg->len); > + > + dev_dbg(dev->dev, "done with err=%d\n", dev->cmd_err); > + > + return dev->cmd_err; > +} > + > + > +static int > +stmp378x_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) > +{ > + int i; > + int err; > + > + if (!msgs->len) > + return -EINVAL; > + > + for (i = 0; i < num; i++) { > + err = stmp378x_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1))); > + if (err) > + return err; > + } > + return num; > +} > + > +static u32 > +stmp378x_i2c_func(struct i2c_adapter *adap) > +{ > + return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); > +} > + > +#define I2C_IRQ_MASK 0x000000FF > +static irqreturn_t > +stmp378x_i2c_isr(int this_irq, void *dev_id) > +{ > + struct stmp378x_i2c_dev *dev = dev_id; > + u32 stat; > + u32 done_mask = BM_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ | > + BM_I2C_CTRL1_BUS_FREE_IRQ ; > + > + stat = readl(HW_I2C_CTRL1 + dev->io) & I2C_IRQ_MASK; > + if (!stat) > + return IRQ_NONE; > + > + if (stat & BM_I2C_CTRL1_NO_SLAVE_ACK_IRQ) { > + dev->cmd_err = -EREMOTEIO; > + > + /* > + * Stop DMA > + * Clear NAK > + */ > + stmp3xxx_setl(BM_I2C_CTRL1_CLR_GOT_A_NAK, > + HW_I2C_CTRL1 + dev->io); > + stmp3xxx_dma_reset_channel(dev->dma); > + stmp3xxx_dma_clear_interrupt(dev->dma); > + > + complete(&dev->cmd_complete); > + > + goto done; > + } > + > + /* Don't care about BM_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ */ > + if (stat & (BM_I2C_CTRL1_EARLY_TERM_IRQ | > + BM_I2C_CTRL1_MASTER_LOSS_IRQ | > + BM_I2C_CTRL1_SLAVE_STOP_IRQ | > + BM_I2C_CTRL1_SLAVE_IRQ)) { > + dev->cmd_err = -EIO; > + complete(&dev->cmd_complete); > + goto done; > + } > + > + if ((stat & done_mask) == done_mask) > + complete(&dev->cmd_complete); > + > +done: > + stmp3xxx_clearl(stat, dev->io + HW_I2C_CTRL1); > + return IRQ_HANDLED; > +} > + > +static const struct i2c_algorithm stmp378x_i2c_algo = { > + .master_xfer = stmp378x_i2c_xfer, > + .functionality = stmp378x_i2c_func, > +}; > + > + > +static int __devinit > +stmp378x_i2c_probe(struct platform_device *pdev) > +{ > + struct stmp378x_i2c_dev *dev; > + struct i2c_adapter *adap; > + struct resource *mem, *dma; > + int err = 0; > + > + /* NOTE: driver uses the static register mapping */ > + dev = kzalloc(sizeof(struct stmp378x_i2c_dev), GFP_KERNEL); > + if (!dev) { > + dev_err(&pdev->dev, "no mem \n"); > + return -ENOMEM; > + } > + > + dev->irq = platform_get_irq(pdev, 0); /* Error */ > + if (dev->irq < 0) { > + dev_err(&pdev->dev, "no err_irq resource\n"); > + err = -ENODEV; > + goto nores; > + } -ENODEV isn't what you want here, you'll end up losing errors in the higher level. > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!mem) { > + dev_err(&pdev->dev, "no memory window\n"); > + err = -ENODEV; > + goto nores; > + } > + > + dma = platform_get_resource(pdev, IORESOURCE_DMA, 0); > + if (!dma) { > + dev_err(&pdev->dev, "no dma channel\n"); > + err = -ENODEV; > + goto nores; > + } > + dev->dma = dma->start; > + > + dev->dev = &pdev->dev; > + dev->io = ioremap(mem->start, resource_size(mem)); > + if (!dev->io) { > + dev_err(&pdev->dev, "cannot ioremap\n"); > + err = -ENXIO; > + goto nores; > + } > + > + err = request_irq(dev->irq, stmp378x_i2c_isr, 0, pdev->name, dev); > + if (err) { > + dev_err(&pdev->dev, "Can't get IRQ\n"); > + goto no_err_irq; > + } > + > + err = stmp378x_i2c_init(dev); > + if (err) { > + dev_err(&pdev->dev, "HW Init failed\n"); > + goto init_failed; > + } > + > + stmp3xxx_setl(0xFF00, dev->io + HW_I2C_CTRL1); > + > + adap = &dev->adapter; > + i2c_set_adapdata(adap, dev); > + adap->owner = THIS_MODULE; > + adap->class = I2C_CLASS_HWMON; is this the correct class? > + strncpy(adap->name, "378x I2C adapter", sizeof(adap->name)); > + adap->algo = &stmp378x_i2c_algo; > + adap->dev.parent = &pdev->dev; > + > + adap->nr = pdev->id; > + err = i2c_add_numbered_adapter(adap); > + if (err) { > + dev_err(&pdev->dev, "Failed to add adapter\n"); > + goto no_i2c_adapter; > + > + } > + > + return 0; > + > +no_i2c_adapter: > + stmp378x_i2c_release(dev); > +init_failed: > + free_irq(dev->irq, dev); > +no_err_irq: > + iounmap(dev->io); > +nores: > + kfree(dev); > + return err; > +} > + > +static int __devexit > +stmp378x_i2c_remove(struct platform_device *pdev) > +{ > + struct stmp378x_i2c_dev *dev = platform_get_drvdata(pdev); > + int res; > + > + res = i2c_del_adapter(&dev->adapter); > + if (res) > + return -EBUSY; > + > + stmp378x_i2c_release(dev); > + > + platform_set_drvdata(pdev, NULL); > + > + free_irq(dev->irq, dev); > + iounmap(dev->io); > + > + kfree(dev); > + return 0; > +} > + > +static struct platform_driver stmp378x_i2c_driver = { > + .probe = stmp378x_i2c_probe, > + .remove = __devexit_p(stmp378x_i2c_remove), > + .driver = { > + .name = "i2c_stmp", > + .owner = THIS_MODULE, > + }, > +}; > + > +static int __init stmp378x_i2c_init_driver(void) > +{ > + return platform_driver_register(&stmp378x_i2c_driver); > +} > +module_init(stmp378x_i2c_init_driver); > + > +static void __exit stmp378x_i2c_exit_driver(void) > +{ > + platform_driver_unregister(&stmp378x_i2c_driver); > +} > +module_exit(stmp378x_i2c_exit_driver); > + > +MODULE_AUTHOR("d.frasenyak@xxxxxxxxxxxxxxxxx"); > +MODULE_DESCRIPTION("I2C for Freescale STMP378x"); > +MODULE_LICENSE("GPL"); no module alias for autoloading? > > -- > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Ben (ben@xxxxxxxxx, http://www.fluff.org/) 'a smiley only costs 4 bytes' -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
