From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754723AbaFPIwo (ORCPT ); Mon, 16 Jun 2014 04:52:44 -0400 Received: from mailsender.cdac.in ([196.1.113.117]:58285 "EHLO mailsender.cdac.in" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754461AbaFPIwn (ORCPT ); Mon, 16 Jun 2014 04:52:43 -0400 Message-ID: <539EB007.9000302@cdac.in> Date: Mon, 16 Jun 2014 14:21:19 +0530 From: Varka Bhadram User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Alexander Aring , Varka Bhadram CC: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-zigbee-devel@lists.sourceforge.net, davem@davemloft.net Subject: Re: [Linux-zigbee-devel] [PATCH net-next 1/3] ieee802154: cc2520: driver for TI cc2520 radio References: <1402894318-30349-1-git-send-email-varkab@cdac.in> <1402894318-30349-2-git-send-email-varkab@cdac.in> <20140616073853.GA20343@omega> In-Reply-To: <20140616073853.GA20343@omega> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CDAC-PUNE-MailScanner-ID: s5G8qJpD020729 X-CDAC-PUNE-MailScanner: Found to be clean, Found to be clean X-CDAC-PUNE-MailScanner-SpamCheck: not spam, SpamAssassin (cached, score=-3, required 6, autolearn=disabled, ALL_TRUSTED -1.00, BAYES_50 0.80, RP_MATCHES_RCVD -2.80), not spam, SpamAssassin (cached, score=-2.91, required 6, autolearn=disabled, ALL_TRUSTED -1.80, BAYES_05 -1.11) X-CDAC-PUNE-MailScanner-Information: Please contact npsfhelp@cdac.in/mailadmin@cdac.in for more information X-MailScanner-ID: s5G8qPSw021778 X-CDAC-PUNE-MailScanner-From: varkab@cdac.in X-CDAC-MailScanner-Spam-Status: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Alex, Thanks for the comments. I will create a patch for the required changes with Reported-by Alexander Aring <...> reply if this is okay for you. On 06/16/2014 01:08 PM, Alexander Aring wrote: > Hi Varka, > > On Mon, Jun 16, 2014 at 10:21:56AM +0530, Varka Bhadram wrote: > Maybe some more information about this chip in the commit msg? I will provide the proper commit messages in next version > > +/*Generic Functions*/ > +static int cc2520_cmd_strobe(struct cc2520_private *priv, > + u8 cmd) > +{ > + int ret; > + u8 status = 0xff; > + struct spi_message msg; > + struct spi_transfer xfer = { > + .len = 0, > + .tx_buf = priv->buf, > + .rx_buf = priv->buf, > + }; > + > + spi_message_init(&msg); > + spi_message_add_tail(&xfer, &msg); > I see, you maybe looked at others drivers like at86rf230 and see what > they do there. I really don't like the lowlevel spi calls in the others > drivers. There are spi helper functions like 'spi_write_then_read' look > in drivers/spi/spi.c for the helper functions. Then you don't need the > buffer_mutex also. In at86rf230 driver first it hold the mutex lock for buffer then __at86rf230_read_subreg()/ __at86rf230_write() functions called. One more thing is that at the low level spi core is holding the lock for the buffer data. We can remove the buffer mutex. >> + >> + mutex_lock(&priv->buffer_mutex); >> + priv->buf[xfer.len++] = cmd; >> + dev_vdbg(&priv->spi->dev, >> + "command strobe buf[0] = %02x\n", >> + priv->buf[0]); >> + >> + ret = spi_sync(priv->spi, &msg); >> + if (!ret) >> + status = priv->buf[0]; >> + dev_vdbg(&priv->spi->dev, >> + "buf[0] = %02x\n", priv->buf[0]); >> + mutex_unlock(&priv->buffer_mutex); >> + >> + return ret; >> +} >> + > .... > >> + >> +static void cc2520_unregister(struct cc2520_private *priv) >> +{ >> + ieee802154_unregister_device(priv->dev); >> + ieee802154_free_device(priv->dev); >> +} > Only used in remove callback of module. It's small enough to do this in > the remove callback. > Ya its nice . We can save the cpu context switching time also.... >> + >> +static void cc2520_fifop_irqwork(struct work_struct *work) >> +{ >> + struct cc2520_private *priv >> + = container_of(work, struct cc2520_private, fifop_irqwork); >> + >> + dev_dbg(&priv->spi->dev, "fifop interrupt received\n"); >> + >> + if (gpio_get_value(priv->fifo_pin)) >> + cc2520_rx(priv); >> + else >> + dev_err(&priv->spi->dev, "rxfifo overflow\n"); >> + >> + cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX); >> + cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX); >> +} >> + >> +static irqreturn_t cc2520_fifop_isr(int irq, void *data) >> +{ >> + struct cc2520_private *priv = data; >> + >> + schedule_work(&priv->fifop_irqwork); >> + >> + return IRQ_HANDLED; >> +} >> + >> +static irqreturn_t cc2520_sfd_isr(int irq, void *data) >> +{ >> + struct cc2520_private *priv = data; >> + >> + spin_lock(&priv->lock); > You need to use here spin_lock_irqsave and spin_unlock_irqrestore here. > Please verify you locking with PROVE_LOCKING enabled in your kernel. > > In your xmit callback you use a irqsave spinlocks there. You need always > save to the "strongest" context which is a interrupt in your case. This type of mechanism is needed when you want to remember the interrupt status for the IRQ/system. >> + if (priv->is_tx) { >> + dev_dbg(&priv->spi->dev, "SFD for TX\n"); >> + priv->is_tx = 0; >> + complete(&priv->tx_complete); >> + } else >> + dev_dbg(&priv->spi->dev, "SFD for RX\n"); > make brackets in the else branch if you have brackets in the "if" branch. > > You don't need to lock all the things here I think: > > --snip > spin_lock_irqsave(&priv->lock, flags); > if (priv->is_tx) { > priv->is_tx = 0; > spin_unlock_irqrestore(&priv->lock, flags); > dev_dbg(&priv->spi->dev, "SFD for TX\n"); > complete(&priv->tx_complete); > } else { > spin_unlock_irqrestore(&priv->lock, flags); > dev_dbg(&priv->spi->dev, "SFD for RX\n"); > } > --snap > Ya this can be the good approach... >> + spin_unlock(&priv->lock); >> + >> + return IRQ_HANDLED >> +/*Driver probe function*/ >> +static int cc2520_probe(struct spi_device *spi) >> +{ >> + struct cc2520_private *priv; >> + struct pinctrl *pinctrl; >> + struct cc2520_platform_data *pdata; >> + struct device_node __maybe_unused *np = spi->dev.of_node; >> + int ret; >> + >> + priv = kzalloc(sizeof(struct cc2520_private), GFP_KERNEL); >> + if (!priv) { >> + ret = -ENOMEM; >> + goto err_free_local; >> + } > why not devm_ calls? I will surely change it to devm_.... >> + >> + spi_set_drvdata(spi, priv); >> + >> + pinctrl = devm_pinctrl_get_select_default(&spi->dev); >> + >> + if (gpio_is_valid(pdata->vreg)) { >> + ret = devm_gpio_request_one(&spi->dev, pdata->vreg, >> + GPIOF_OUT_INIT_LOW, "vreg"); >> + if (ret) >> + goto err_hw_init; >> + } > You should check on the not optional pins if you can request them. You > use in the above code the pins vreg, reset, fifo_irq, sfd. And this > failed if the gpio's are not valid. > > means: > > if (!gpio_is_valid(pdata->vreg)) { > dev_err(....) > ret = -EINVAL; > goto ...; > } > > on all pins which are needed to use your chip. > >> + >> + gpio_set_value(pdata->vreg, HIGH); >> + udelay(100); >> + >> + gpio_set_value(pdata->reset, HIGH); >> + udelay(200); >> + >> + ret = cc2520_hw_init(priv); >> + if (ret) >> + goto err_hw_init; >> + >> + /*Set up fifop interrupt */ >> + priv->fifo_irq = gpio_to_irq(pdata->fifop); > why is fifo_irq in your "private data"? This is only used in this function. Ya this is my mistake. Previously i used in other place also. >> + ret = devm_request_irq(&spi->dev, >> + priv->fifo_irq, >> + cc2520_fifop_isr, >> + IRQF_TRIGGER_RISING, >> + dev_name(&spi->dev), >> + priv); >> + if (ret) { >> + dev_err(&spi->dev, "could not get fifop irq\n"); >> + goto err_hw_init; >> + } >> + >> + /*Set up sfd interrupt*/ >> + ret = devm_request_irq(&spi->dev, >> + gpio_to_irq(pdata->sfd), >> + cc2520_sfd_isr, >> + IRQF_TRIGGER_FALLING, >> + dev_name(&spi->dev), >> + priv); >> + if (ret) { >> + dev_err(&spi->dev, "could not get sfd irq\n"); >> + goto err_hw_init; >> + } >> + >> + ret = cc2520_register(priv); >> + if (ret) >> + goto err_hw_init; >> + >> + return 0; >> + >> +err_hw_init: >> + mutex_destroy(&priv->buffer_mutex); >> + flush_work(&priv->fifop_irqwork); >> + >> +err_free_buf: >> + kfree(priv->buf); >> + >> +err_free_local: >> + kfree(priv); >> + >> + return ret; >> +} >> + >> +/*Driver remove function*/ >> +static int cc2520_remove(struct spi_device *spi) >> +{ >> + struct cc2520_private *priv = spi_get_drvdata(spi); >> + >> + cc2520_unregister(priv); >> + >> + mutex_destroy(&priv->buffer_mutex); >> + flush_work(&priv->fifop_irqwork); >> + >> + kfree(priv->buf); >> + kfree(priv); >> + >> + return 0; >> +} >> + >> +static const struct spi_device_id cc2520_ids[] = { >> + {"cc2520", 0}, > You don't need to set the driver_data to 0. Simple: > { "cc2520", }, this does not make any difference. >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(spi, cc2520_ids); >> + >> +static const struct of_device_id cc2520_of_ids[] = { >> + {.compatible = "ti,cc2520", }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, cc2520_of_ids); >> + >> +/*SPI Driver Structure*/ >> +static struct spi_driver cc2520_driver = { >> + .driver = { >> + .name = "cc2520", >> + .bus = &spi_bus_type, >> + .owner = THIS_MODULE, >> + .of_match_table = of_match_ptr(cc2520_of_ids), >> + }, >> + .id_table = cc2520_ids, >> + .probe = cc2520_probe, >> + .remove = cc2520_remove, >> +}; >> +module_spi_driver(cc2520_driver); >> + >> +MODULE_DESCRIPTION("CC2520 Transceiver Driver"); >> +MODULE_LICENSE("GPL v2"); >> diff --git a/include/linux/spi/cc2520.h b/include/linux/spi/cc2520.h >> new file mode 100644 >> index 0000000..68a2c88 >> --- /dev/null >> +++ b/include/linux/spi/cc2520.h > In this location of header files are platform_data structs only. I think > you should leave the cc2520_platform_data in this file and move the rest > of declaration to you cc2520.c file. > I will move the code >> @@ -0,0 +1,176 @@ >> +#ifndef __CC2520_H >> +#define __CC2520_H >> + >> +#define RSSI_VALID 0 >> +#define RSSI_OFFSET 78 >> +#define CC2520_FREG_MASK 0x3F >> + >> +struct cc2520_platform_data { >> + int fifo; >> + int fifop; >> + int cca; >> + int sfd; >> + int reset; >> + int vreg; >> +}; >> + > - Alex -Varka Bhadram ------------------------------------------------------------------------------------------------------------------------------- [ C-DAC is on Social-Media too. Kindly follow us at: Facebook: https://www.facebook.com/CDACINDIA & Twitter: @cdacindia ] This e-mail is for the sole use of the intended recipient(s) and may contain confidential and privileged information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies and the original message. 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