Re: [Linux-stm32] [PATCH v16 03/14] counter: Internalize sysfs interface code
From: William Breathitt Gray <hidden>
Date: 2021-08-31 14:17:13
On Tue, Aug 31, 2021 at 03:44:04PM +0200, Fabrice Gasnier wrote:
On 8/27/21 5:47 AM, William Breathitt Gray wrote:quoted
This is a reimplementation of the Generic Counter driver interface. There are no modifications to the Counter subsystem userspace interface, so existing userspace applications should continue to run seamlessly. The purpose of this patch is to internalize the sysfs interface code among the various counter drivers into a shared module. Counter drivers pass and take data natively (i.e. u8, u64, etc.) and the shared counter module handles the translation between the sysfs interface and the device drivers. This guarantees a standard userspace interface for all counter drivers, and helps generalize the Generic Counter driver ABI in order to support the Generic Counter chrdev interface (introduced in a subsequent patch) without significant changes to the existing counter drivers. Note, Counter device registration is the same as before: drivers populate a struct counter_device with components and callbacks, then pass the structure to the devm_counter_register function. However, what's different now is how the Counter subsystem code handles this registration internally. Whereas before callbacks would interact directly with sysfs data, this interaction is now abstracted and instead callbacks interact with native C data types. The counter_comp structure forms the basis for Counter extensions. The counter-sysfs.c file contains the code to parse through the counter_device structure and register the requested components and extensions. Attributes are created and populated based on type, with respective translation functions to handle the mapping between sysfs and the counter driver callbacks. The translation performed for each attribute is straightforward: the attribute type and data is parsed from the counter_attribute structure, the respective counter driver read/write callback is called, and sysfs I/O is handled before or after the driver read/write function is called. Cc: Jarkko Nikula <redacted> Cc: Patrick Havelange <patrick.havelange@essensium.com> Cc: Kamel Bouhara <kamel.bouhara@bootlin.com> Cc: Fabrice Gasnier <redacted> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <redacted> Cc: Dan Carpenter <redacted> Acked-by: Syed Nayyar Waris <redacted> Reviewed-by: David Lechner <david@lechnology.com> Tested-by: David Lechner <david@lechnology.com> Signed-off-by: William Breathitt Gray <redacted> --- MAINTAINERS | 1 - drivers/counter/104-quad-8.c | 449 +++---- drivers/counter/Makefile | 1 + drivers/counter/counter-core.c | 142 +++ drivers/counter/counter-sysfs.c | 849 +++++++++++++ drivers/counter/counter-sysfs.h | 13 + drivers/counter/counter.c | 1496 ----------------------- drivers/counter/ftm-quaddec.c | 60 +- drivers/counter/intel-qep.c | 144 +-- drivers/counter/interrupt-cnt.c | 62 +- drivers/counter/microchip-tcb-capture.c | 91 +- drivers/counter/stm32-lptimer-cnt.c | 212 ++-- drivers/counter/stm32-timer-cnt.c | 179 ++- drivers/counter/ti-eqep.c | 180 +-- include/linux/counter.h | 658 +++++----- include/linux/counter_enum.h | 45 - 16 files changed, 1949 insertions(+), 2633 deletions(-) create mode 100644 drivers/counter/counter-core.c create mode 100644 drivers/counter/counter-sysfs.c create mode 100644 drivers/counter/counter-sysfs.h delete mode 100644 drivers/counter/counter.c delete mode 100644 include/linux/counter_enum.hHi William, For the STM32 drivers, you can add my: Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> Thanks, Fabrice
Hello Fabrice, I noticed the stm32-lptimer-cnt.c function_write() and action_write() callbacks do not appear to write the desired function/action configuration to the device. Would you check whether the device actually supports this functionality or if these callbacks should be removed from this driver. Thanks, William Breathitt Gray
quoted
diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c index 7367f46c6f91..5168833b1fdf 100644 --- a/drivers/counter/stm32-lptimer-cnt.c +++ b/drivers/counter/stm32-lptimer-cnt.c@@ -170,28 +154,28 @@ static int stm32_lptim_cnt_read(struct counter_device *counter, return 0; } -static int stm32_lptim_cnt_function_get(struct counter_device *counter, - struct counter_count *count, - size_t *function) +static int stm32_lptim_cnt_function_read(struct counter_device *counter, + struct counter_count *count, + enum counter_function *function) { struct stm32_lptim_cnt *const priv = counter->priv; if (!priv->quadrature_mode) { - *function = STM32_LPTIM_COUNTER_INCREASE; + *function = COUNTER_FUNCTION_INCREASE; return 0; } - if (priv->polarity == STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES) { - *function = STM32_LPTIM_ENCODER_BOTH_EDGE; + if (priv->polarity == STM32_LPTIM_CKPOL_BOTH_EDGES) { + *function = COUNTER_FUNCTION_QUADRATURE_X4; return 0; } return -EINVAL; } -static int stm32_lptim_cnt_function_set(struct counter_device *counter, - struct counter_count *count, - size_t function) +static int stm32_lptim_cnt_function_write(struct counter_device *counter, + struct counter_count *count, + enum counter_function function) { struct stm32_lptim_cnt *const priv = counter->priv;@@ -199,12 +183,12 @@ static int stm32_lptim_cnt_function_set(struct counter_device *counter, return -EBUSY; switch (function) { - case STM32_LPTIM_COUNTER_INCREASE: + case COUNTER_FUNCTION_INCREASE: priv->quadrature_mode = 0; return 0; - case STM32_LPTIM_ENCODER_BOTH_EDGE: + case COUNTER_FUNCTION_QUADRATURE_X4: priv->quadrature_mode = 1; - priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES; + priv->polarity = STM32_LPTIM_CKPOL_BOTH_EDGES; return 0; default: /* should never reach this path */@@ -333,43 +316,48 @@ static int stm32_lptim_cnt_action_get(struct counter_device *counter, } } -static int stm32_lptim_cnt_action_set(struct counter_device *counter, - struct counter_count *count, - struct counter_synapse *synapse, - size_t action) +static int stm32_lptim_cnt_action_write(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + enum counter_synapse_action action) { struct stm32_lptim_cnt *const priv = counter->priv; - size_t function; + enum counter_function function; int err; if (stm32_lptim_is_enabled(priv)) return -EBUSY; - err = stm32_lptim_cnt_function_get(counter, count, &function); + err = stm32_lptim_cnt_function_read(counter, count, &function); if (err) return err; /* only set polarity when in counter mode (on input 1) */ - if (function == STM32_LPTIM_COUNTER_INCREASE - && synapse->signal->id == count->synapses[0].signal->id) { - switch (action) { - case STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE: - case STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE: - case STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES: - priv->polarity = action; - return 0; - } - } + if (function != COUNTER_FUNCTION_INCREASE + || synapse->signal->id != count->synapses[0].signal->id) + return -EINVAL; - return -EINVAL; + switch (action) { + case COUNTER_SYNAPSE_ACTION_RISING_EDGE: + priv->polarity = STM32_LPTIM_CKPOL_RISING_EDGE; + return 0; + case COUNTER_SYNAPSE_ACTION_FALLING_EDGE: + priv->polarity = STM32_LPTIM_CKPOL_FALLING_EDGE; + return 0; + case COUNTER_SYNAPSE_ACTION_BOTH_EDGES: + priv->polarity = STM32_LPTIM_CKPOL_BOTH_EDGES; + return 0; + default: + return -EINVAL; + } }