From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752721AbdEJL5K (ORCPT ); Wed, 10 May 2017 07:57:10 -0400 Received: from krieglstein.org ([176.28.13.145]:39298 "EHLO krieglstein.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751123AbdEJL5J (ORCPT ); Wed, 10 May 2017 07:57:09 -0400 From: Tim Sander To: Phil Reid Cc: Jarkko Nikula , Andy Shevchenko , Mika Westerberg , Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] i2c-designware: add i2c gpio recovery option Date: Wed, 10 May 2017 13:57:06 +0200 Message-ID: <32490844.DoY2McpBxU@dabox> Organization: Sander and Lightning User-Agent: KMail/5.1.3 (Linux/4.9.2; KDE/5.18.0; x86_64; ; ) In-Reply-To: <4a84d6b1-2bba-6f01-8286-49661ef45576@electromag.com.au> References: <2259005.m0altzP21Z@dabox> <1966782.aCEMFj2YWU@virgo> <4a84d6b1-2bba-6f01-8286-49661ef45576@electromag.com.au> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch contains much input from Phil Reid and has been tested on Intel/Altera Cyclone V SOC Hardware with Altera GPIO's for the SCL and SDA GPIO's. I am still a little unsure about the recover in the timeout case (i2c-designware-core.c:770) as i could not test this codepath. Signed-off-by: Tim Sander --- drivers/i2c/busses/i2c-designware-core.c | 14 ++++- drivers/i2c/busses/i2c-designware-core.h | 4 ++ drivers/i2c/busses/i2c-designware-platdrv.c | 90 ++++++++++++++++++++++++++++- 3 files changed, 104 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 7a3faa551cf8..f955f29ff8e7 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -317,6 +317,7 @@ static void i2c_dw_release_lock(struct dw_i2c_dev *dev) dev->release_lock(dev); } + /** * i2c_dw_init() - initialize the designware i2c master hardware * @dev: device private data @@ -463,7 +464,12 @@ static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev) while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) { if (timeout <= 0) { dev_warn(dev->dev, "timeout waiting for bus ready\n"); - return -ETIMEDOUT; + i2c_recover_bus(&dev->adapter); + + if (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) + return -ETIMEDOUT; + else + return 0; } timeout--; usleep_range(1000, 1100); @@ -719,9 +725,10 @@ static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev) for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]); - if (abort_source & DW_IC_TX_ARB_LOST) + if (abort_source & DW_IC_TX_ARB_LOST) { + i2c_recover_bus(&dev->adapter); return -EAGAIN; - else if (abort_source & DW_IC_TX_ABRT_GCALL_READ) + } else if (abort_source & DW_IC_TX_ABRT_GCALL_READ) return -EINVAL; /* wrong msgs[] data */ else return -EIO; @@ -766,6 +773,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) { dev_err(dev->dev, "controller timed out\n"); /* i2c_dw_init implicitly disables the adapter */ + i2c_recover_bus(&dev->adapter); i2c_dw_init(dev); ret = -ETIMEDOUT; goto done; diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index d9aaf1790e0e..cedc895a795d 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -23,6 +23,7 @@ */ #include +#include #define DW_IC_DEFAULT_FUNCTIONALITY (I2C_FUNC_I2C | \ I2C_FUNC_SMBUS_BYTE | \ @@ -126,6 +127,9 @@ struct dw_i2c_dev { int (*acquire_lock)(struct dw_i2c_dev *dev); void (*release_lock)(struct dw_i2c_dev *dev); bool pm_runtime_disabled; + struct i2c_bus_recovery_info rinfo; + struct gpio_desc *gpio_sda; + struct gpio_desc *gpio_scl; }; #define ACCESS_SWAP 0x00000001 diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 79c4b4ea0539..b2d5adc8df2b 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include "i2c-designware-core.h" @@ -174,6 +175,88 @@ static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) } } +/* + * This routine does i2c bus recovery by using i2c_generic_gpio_recovery + * which is provided by I2C Bus recovery infrastructure. + */ +static void i2c_dw_prepare_recovery(struct i2c_adapter *adap) +{ + struct platform_device *pdev = to_platform_device(&adap->dev); + struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); + + i2c_dw_disable(i_dev); + reset_control_assert(i_dev->rst); + i2c_dw_plat_prepare_clk(i_dev, false); +} + +void i2c_dw_unprepare_recovery(struct i2c_adapter *adap) +{ + struct platform_device *pdev = to_platform_device(&adap->dev); + struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); + + i2c_dw_plat_prepare_clk(i_dev, true); + reset_control_deassert(i_dev->rst); + i2c_dw_init(i_dev); +} + + +static int i2c_dw_get_scl(struct i2c_adapter *adap) +{ + struct platform_device *pdev = to_platform_device(&adap->dev); + struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + + return gpiod_get_value_cansleep(dev->gpio_scl); +} + +static void i2c_dw_set_scl(struct i2c_adapter *adap, int val) +{ + struct platform_device *pdev = to_platform_device(&adap->dev); + struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + + gpiod_set_value_cansleep(dev->gpio_scl, val); +} + +static int i2c_dw_get_sda(struct i2c_adapter *adap) +{ + struct platform_device *pdev = to_platform_device(&adap->dev); + struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + + return gpiod_get_value_cansleep(dev->gpio_sda); +} + +static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev, + struct i2c_adapter *adap) +{ + struct i2c_bus_recovery_info *rinfo = &dev->rinfo; + + dev->gpio_scl = devm_gpiod_get_optional(dev->dev, + "scl", + GPIOD_OUT_HIGH); + if (IS_ERR_OR_NULL(dev->gpio_scl)) + return PTR_ERR(dev->gpio_scl); + + dev->gpio_sda = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN); + if (IS_ERR_OR_NULL(dev->gpio_sda)) + return PTR_ERR(dev->gpio_sda); + + rinfo->scl_gpio = desc_to_gpio(dev->gpio_scl); + rinfo->sda_gpio = desc_to_gpio(dev->gpio_sda); + rinfo->set_scl = i2c_dw_set_scl; + rinfo->get_scl = i2c_dw_get_scl; + rinfo->get_sda = i2c_dw_get_sda; + + rinfo->recover_bus = i2c_generic_scl_recovery; + rinfo->prepare_recovery = i2c_dw_prepare_recovery; + rinfo->unprepare_recovery = i2c_dw_unprepare_recovery; + adap->bus_recovery_info = rinfo; + + dev_info(dev->dev, + "adapter: %s running with gpio recovery mode! scl:%i sda:%i \n", + adap->name, rinfo->scl_gpio, rinfo->sda_gpio); + + return 0; +}; + static int dw_i2c_plat_probe(struct platform_device *pdev) { struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); @@ -285,6 +368,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) adap->class = I2C_CLASS_DEPRECATED; ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); adap->dev.of_node = pdev->dev.of_node; + snprintf(adap->name, sizeof(adap->name), "Designware i2c adapter"); if (dev->pm_runtime_disabled) { pm_runtime_forbid(&pdev->dev); @@ -295,11 +379,15 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) pm_runtime_enable(&pdev->dev); } + r = i2c_dw_init_recovery_info(dev, adap); + if (r == -EPROBE_DEFER) + goto exit_probe; + r = i2c_dw_probe(dev); if (r) goto exit_probe; - return r; + return 0; exit_probe: if (!dev->pm_runtime_disabled) -- 2.7.4