spi: spi_qsd: Reduce latency for non-shared cores (eff02b00) · Commits · e / devices / android_kernel_sony_msm8994

Documentation/devicetree/bindings/spi/spi_qsd.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@ Optional properties:
		- qcom,rt-priority : whether spi message queue is set to run as a realtime task.
		With this spi transaction message pump with high (realtime) priority to reduce
		the transfer latency on the bus by minimising the delay between a transfer request
		- qcom,shared : whether this qup is shared with other ee's

		Optional properties which are required for support of BAM-mode:
		- qcom,ver-reg-exists : Boolean. When present, allows driver to verify if HW

drivers/spi/spi_qsd.c

+42 −20

Original line number	Diff line number	Diff line
		/* Copyright (c) 2008-2014, The Linux Foundation. All rights reserved.
		/* Copyright (c) 2008-2015, The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -1854,6 +1854,7 @@ static int msm_spi_transfer_one_message(struct spi_master *master,
		* get local resources for each transfer to ensure we're in a good
		* state and not interfering with other EE's using this device
		*/
		if (dd->pdata->is_shared) {
		if (get_local_resources(dd)) {
		mutex_unlock(&dd->core_lock);
		return -EINVAL;
		@@ -1866,6 +1867,7 @@ static int msm_spi_transfer_one_message(struct spi_master *master,
		msm_spi_bam_pipe_connect(dd, &dd->bam.cons,
		&dd->bam.cons.config);
		}
		}

		if (dd->suspended \|\| !msm_spi_is_valid_state(dd)) {
		dev_err(dd->dev, "%s: SPI operational state not valid\n",
		@@ -1891,11 +1893,13 @@ static int msm_spi_transfer_one_message(struct spi_master *master,
		* different context since we're running in the spi kthread here) to
		* prevent race conditions between us and any other EE's using this hw.
		*/
		if (dd->pdata->is_shared) {
		if (dd->use_dma) {
		msm_spi_bam_pipe_disconnect(dd, &dd->bam.prod);
		msm_spi_bam_pipe_disconnect(dd, &dd->bam.cons);
		}
		put_local_resources(dd);
		}
		mutex_unlock(&dd->core_lock);
		if (dd->suspended)
		wake_up_interruptible(&dd->continue_suspend);
		@@ -1985,9 +1989,11 @@ static int msm_spi_setup(struct spi_device *spi)
		goto err_setup_exit;
		}

		if (dd->pdata->is_shared) {
		rc = get_local_resources(dd);
		if (rc)
		goto no_resources;
		}

		spi_ioc = readl_relaxed(dd->base + SPI_IO_CONTROL);
		mask = SPI_IO_C_CS_N_POLARITY_0 << spi->chip_select;
		@@ -2006,6 +2012,7 @@ static int msm_spi_setup(struct spi_device *spi)

		/* Ensure previous write completed before disabling the clocks */
		mb();
		if (dd->pdata->is_shared)
		put_local_resources(dd);
		/* Counter-part of system-resume when runtime-pm is not enabled. */
		if (!pm_runtime_enabled(dd->dev))
		@@ -2421,6 +2428,8 @@ struct msm_spi_platform_data *msm_spi_dt_to_pdata(
		&dd->cs_gpios[3].gpio_num, DT_OPT, DT_GPIO, -1},
		{"qcom,rt-priority",
		&pdata->rt_priority, DT_OPT, DT_BOOL, 0},
		{"qcom,shared",
		&pdata->is_shared, DT_OPT, DT_BOOL, 0},
		{NULL, NULL, 0, 0, 0},
		};

		@@ -2800,9 +2809,14 @@ static int msm_spi_pm_suspend_runtime(struct device *device)
		wait_event_interruptible(dd->continue_suspend,
		!dd->transfer_pending);

		if (dd->pdata && !dd->pdata->is_shared && dd->use_dma) {
		msm_spi_bam_pipe_disconnect(dd, &dd->bam.prod);
		msm_spi_bam_pipe_disconnect(dd, &dd->bam.cons);
		}
		if (dd->pdata && !dd->pdata->active_only)
		msm_spi_clk_path_unvote(dd);

		if (dd->pdata && !dd->pdata->is_shared)
		put_local_resources(dd);
		suspend_exit:
		return 0;
		}
		@@ -2830,9 +2844,17 @@ static int msm_spi_pm_resume_runtime(struct device *device)
		else
		dd->is_init_complete = true;
		}
		if (!dd->pdata->is_shared)
		get_local_resources(dd);
		msm_spi_clk_path_init(dd);
		if (!dd->pdata->active_only)
		msm_spi_clk_path_vote(dd);
		if (!dd->pdata->is_shared && dd->use_dma) {
		msm_spi_bam_pipe_connect(dd, &dd->bam.prod,
		&dd->bam.prod.config);
		msm_spi_bam_pipe_connect(dd, &dd->bam.cons,
		&dd->bam.cons.config);
		}
		dd->suspended = 0;

		resume_exit:

include/linux/qcom-spi.h

+15 −4

Original line number	Diff line number	Diff line
		/* Copyright (c) 2014 The Linux Foundation. All rights reserved.
		/* Copyright (c) 2014-2015 The Linux Foundation. All rights reserved.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 and
		@@ -17,14 +17,24 @@
		/**
		* msm_spi_platform_data: msm spi-controller's configuration data
		*
		* @max_clock_speed max spi clock speed
		* @active_only when set, votes when system active and removes the vote when
		* system goes idle (optimises for performance). When unset, voting using
		* runtime pm (optimizes for power).
		* @master_id master id number of the controller's wrapper (BLSP or GSBI).
		* When zero, clock path voting is disabled.
		* @rt when set, spi will pump transaction messages with high (realtime)
		* priority to reduce the transfer latency on the bus by minimising
		* the delay between a transfer request.
		* @gpio_config pointer to function for configuring gpio
		* @gpio_release pointer to function for releasing gpio pins
		* @dma_config function poniter for configuring dma engine
		* @pm_lat power management latency
		* @infinite_mode use FIFO mode in infinite mode
		* @ver_reg_exists if the version register exists
		* @use_beam true if BAM is available
		* @bam_consumer_pipe_index BAM conusmer pipe
		* @bam_producer_pipe_index BAM producer pipe
		* @rt_priority true if RT thread
		* @use_pinctrl true if pinctrl library is used
		* @is_shared true when qup is shared between ee's
		*/
		struct msm_spi_platform_data {
		u32 max_clock_speed;
		@@ -42,4 +52,5 @@ struct msm_spi_platform_data {
		u32 bam_producer_pipe_index;
		bool rt_priority;
		bool use_pinctrl;
		bool is_shared;
		};