On Fri, Nov 1, 2013 at 5:49 AM, Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote: > On Wed, Oct 16, 2013 at 03:01:46PM -0700, Tim Kryger wrote: >> Introduce support for Broadcom Serial Controller (BSC) I2C bus found >> in the Kona family of Mobile SoCs. FIFO hardware is utilized but only >> standard mode (100kHz), fast mode (400kHz), and fast mode plus (1MHz) >> bus speeds are supported. >> >> Signed-off-by: Tim Kryger <tim.kryger@xxxxxxxxxx> >> Reviewed-by: Matt Porter <matt.porter@xxxxxxxxxx> >> Reviewed-by: Markus Mayer <markus.mayer@xxxxxxxxxx> > > Looks mostly good, some remarks: > >> +struct bcm_kona_i2c_dev { >> + /* Pointer to linux device struct */ >> + struct device *device; >> + >> + /* Virtual address where registers are mapped */ >> + void __iomem *base; >> + >> + /* Interrupt */ >> + int irq; >> + >> + /* Standard Speed configuration */ >> + const struct bus_speed_cfg *std_cfg; >> + >> + /* Linux I2C adapter struct */ >> + struct i2c_adapter adapter; >> + >> + /* Lock for the I2C device */ >> + struct mutex i2c_bcm_lock; >> + >> + /* Completion to signal an operation finished */ >> + struct completion done; >> + >> + /* Handle for external clock */ >> + struct clk *external_clk; >> +}; > > IMO most of the comments could go. Kind of stating the obvious :) Sure thing. > >> +/* Read any amount of data using the RX FIFO from the i2c bus */ >> +static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev, >> + struct i2c_msg *msg) >> +{ >> + unsigned int bytes_to_read = MAX_RX_FIFO_SIZE; >> + unsigned int last_byte_nak = 0; >> + unsigned int bytes_read = 0; >> + unsigned int rc; > > Should be signed. Absolutely. Thanks for catching this one. > >> +/* Write any amount of data using TX FIFO to the i2c bus */ >> +static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev, >> + struct i2c_msg *msg) >> +{ >> + unsigned int bytes_to_write = MAX_TX_FIFO_SIZE; >> + unsigned int bytes_written = 0; >> + unsigned int rc; > > Ditto signed. I shall fix it. > >> +/* Master transfer function */ >> +static int bcm_kona_i2c_xfer(struct i2c_adapter *adapter, >> + struct i2c_msg msgs[], int num) >> +{ >> + struct bcm_kona_i2c_dev *dev = i2c_get_adapdata(adapter); >> + struct i2c_msg *pmsg; >> + int rc = 0; >> + int i; >> + >> + mutex_lock(&dev->i2c_bcm_lock); > > Huh? Why do you need that? The core has locks per bus. In that case, I will remove the local mutex. >> +static int bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev) >> +{ >> + unsigned int bus_speed; >> + int ret = of_property_read_u32(dev->device->of_node, "clock-frequency", >> + &bus_speed); >> + if (ret < 0) { >> + dev_err(dev->device, "missing clock-frequency property\n"); >> + return -ENODEV; >> + } >> + >> + switch (bus_speed) { >> + case 100000: >> + dev->std_cfg = &std_cfg_table[BCM_SPD_100K]; >> + break; >> + case 400000: >> + dev->std_cfg = &std_cfg_table[BCM_SPD_400K]; >> + break; >> + case 1000000: >> + dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ]; >> + break; >> + default: >> + pr_err("%d hz bus speed not supported\n", bus_speed); >> + return -EINVAL; >> + }; > > Unneeded semicolon. > Sure. It will be removed. >> + >> + return 0; >> +} >> + >> +static int bcm_kona_i2c_probe(struct platform_device *pdev) >> +{ >> + int rc = 0; >> + struct bcm_kona_i2c_dev *dev; >> + struct i2c_adapter *adap; >> + struct resource *iomem; >> + >> + /* Allocate memory for private data structure */ >> + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); >> + if (!dev) { >> + rc = -ENOMEM; >> + goto probe_return; > > I'd prefer simply return -Esomething. The printout at probe_return is > also available via driver core. Agreed. > ... > >> + /* Add the i2c adapter */ >> + adap = &dev->adapter; >> + i2c_set_adapdata(adap, dev); >> + adap->owner = THIS_MODULE; >> + adap->class = UINT_MAX; /* can be used by any I2C device */ > > Why do you need class based instantiation. It will most likely cost > boot-time and you have devicetree means for doing instantiation. > > Agreed. >> + strlcpy(adap->name, "Broadcom I2C adapter", sizeof(adap->name)); >> + adap->algo = &bcm_algo; >> + adap->dev.parent = &pdev->dev; >> + adap->nr = pdev->id; >> + adap->dev.of_node = pdev->dev.of_node; >> + >> + rc = i2c_add_numbered_adapter(adap); > > Maybe you want simply i2c_add_adapter here since the core has no > built-in support for of aliases? > Okay. I will switch to i2c_add_adapter and remove the adap->nr assignment. >> + >> +MODULE_AUTHOR("Broadcom"); > > Some email address please. > >> +MODULE_DESCRIPTION("Broadcom Kona I2C Driver"); >> +MODULE_LICENSE("GPL v2"); > > Thanks, > > Wolfram > -- 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