diff options
Diffstat (limited to 'drivers/dma/stm32-dmamux.c')
| -rw-r--r-- | drivers/dma/stm32-dmamux.c | 327 |
1 files changed, 0 insertions, 327 deletions
diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c deleted file mode 100644 index b922db90939a..000000000000 --- a/drivers/dma/stm32-dmamux.c +++ /dev/null @@ -1,327 +0,0 @@ -/* - * - * Copyright (C) STMicroelectronics SA 2017 - * Author(s): M'boumba Cedric Madianga <cedric.madianga@gmail.com> - * Pierre-Yves Mordret <pierre-yves.mordret@st.com> - * - * License terms: GPL V2.0. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published by - * the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more - * details. - * - * DMA Router driver for STM32 DMA MUX - * - * Based on TI DMA Crossbar driver - * - */ - -#include <linux/clk.h> -#include <linux/delay.h> -#include <linux/err.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/of_device.h> -#include <linux/of_dma.h> -#include <linux/reset.h> -#include <linux/slab.h> -#include <linux/spinlock.h> - -#define STM32_DMAMUX_CCR(x) (0x4 * (x)) -#define STM32_DMAMUX_MAX_DMA_REQUESTS 32 -#define STM32_DMAMUX_MAX_REQUESTS 255 - -struct stm32_dmamux { - u32 master; - u32 request; - u32 chan_id; -}; - -struct stm32_dmamux_data { - struct dma_router dmarouter; - struct clk *clk; - struct reset_control *rst; - void __iomem *iomem; - u32 dma_requests; /* Number of DMA requests connected to DMAMUX */ - u32 dmamux_requests; /* Number of DMA requests routed toward DMAs */ - spinlock_t lock; /* Protects register access */ - unsigned long *dma_inuse; /* Used DMA channel */ - u32 dma_reqs[]; /* Number of DMA Request per DMA masters. - * [0] holds number of DMA Masters. - * To be kept at very end end of this structure - */ -}; - -static inline u32 stm32_dmamux_read(void __iomem *iomem, u32 reg) -{ - return readl_relaxed(iomem + reg); -} - -static inline void stm32_dmamux_write(void __iomem *iomem, u32 reg, u32 val) -{ - writel_relaxed(val, iomem + reg); -} - -static void stm32_dmamux_free(struct device *dev, void *route_data) -{ - struct stm32_dmamux_data *dmamux = dev_get_drvdata(dev); - struct stm32_dmamux *mux = route_data; - unsigned long flags; - - /* Clear dma request */ - spin_lock_irqsave(&dmamux->lock, flags); - - stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), 0); - clear_bit(mux->chan_id, dmamux->dma_inuse); - - if (!IS_ERR(dmamux->clk)) - clk_disable(dmamux->clk); - - spin_unlock_irqrestore(&dmamux->lock, flags); - - dev_dbg(dev, "Unmapping DMAMUX(%u) to DMA%u(%u)\n", - mux->request, mux->master, mux->chan_id); - - kfree(mux); -} - -static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, - struct of_dma *ofdma) -{ - struct platform_device *pdev = of_find_device_by_node(ofdma->of_node); - struct stm32_dmamux_data *dmamux = platform_get_drvdata(pdev); - struct stm32_dmamux *mux; - u32 i, min, max; - int ret; - unsigned long flags; - - if (dma_spec->args_count != 3) { - dev_err(&pdev->dev, "invalid number of dma mux args\n"); - return ERR_PTR(-EINVAL); - } - - if (dma_spec->args[0] > dmamux->dmamux_requests) { - dev_err(&pdev->dev, "invalid mux request number: %d\n", - dma_spec->args[0]); - return ERR_PTR(-EINVAL); - } - - mux = kzalloc(sizeof(*mux), GFP_KERNEL); - if (!mux) - return ERR_PTR(-ENOMEM); - - spin_lock_irqsave(&dmamux->lock, flags); - mux->chan_id = find_first_zero_bit(dmamux->dma_inuse, - dmamux->dma_requests); - - if (mux->chan_id == dmamux->dma_requests) { - spin_unlock_irqrestore(&dmamux->lock, flags); - dev_err(&pdev->dev, "Run out of free DMA requests\n"); - ret = -ENOMEM; - goto error_chan_id; - } - set_bit(mux->chan_id, dmamux->dma_inuse); - spin_unlock_irqrestore(&dmamux->lock, flags); - - /* Look for DMA Master */ - for (i = 1, min = 0, max = dmamux->dma_reqs[i]; - i <= dmamux->dma_reqs[0]; - min += dmamux->dma_reqs[i], max += dmamux->dma_reqs[++i]) - if (mux->chan_id < max) - break; - mux->master = i - 1; - - /* The of_node_put() will be done in of_dma_router_xlate function */ - dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", i - 1); - if (!dma_spec->np) { - dev_err(&pdev->dev, "can't get dma master\n"); - ret = -EINVAL; - goto error; - } - - /* Set dma request */ - spin_lock_irqsave(&dmamux->lock, flags); - if (!IS_ERR(dmamux->clk)) { - ret = clk_enable(dmamux->clk); - if (ret < 0) { - spin_unlock_irqrestore(&dmamux->lock, flags); - dev_err(&pdev->dev, "clk_prep_enable issue: %d\n", ret); - goto error; - } - } - spin_unlock_irqrestore(&dmamux->lock, flags); - - mux->request = dma_spec->args[0]; - - /* craft DMA spec */ - dma_spec->args[3] = dma_spec->args[2]; - dma_spec->args[2] = dma_spec->args[1]; - dma_spec->args[1] = 0; - dma_spec->args[0] = mux->chan_id - min; - dma_spec->args_count = 4; - - stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), - mux->request); - dev_dbg(&pdev->dev, "Mapping DMAMUX(%u) to DMA%u(%u)\n", - mux->request, mux->master, mux->chan_id); - - return mux; - -error: - clear_bit(mux->chan_id, dmamux->dma_inuse); - -error_chan_id: - kfree(mux); - return ERR_PTR(ret); -} - -static const struct of_device_id stm32_stm32dma_master_match[] = { - { .compatible = "st,stm32-dma", }, - {}, -}; - -static int stm32_dmamux_probe(struct platform_device *pdev) -{ - struct device_node *node = pdev->dev.of_node; - const struct of_device_id *match; - struct device_node *dma_node; - struct stm32_dmamux_data *stm32_dmamux; - struct resource *res; - void __iomem *iomem; - int i, count, ret; - u32 dma_req; - - if (!node) - return -ENODEV; - - count = device_property_read_u32_array(&pdev->dev, "dma-masters", - NULL, 0); - if (count < 0) { - dev_err(&pdev->dev, "Can't get DMA master(s) node\n"); - return -ENODEV; - } - - stm32_dmamux = devm_kzalloc(&pdev->dev, sizeof(*stm32_dmamux) + - sizeof(u32) * (count + 1), GFP_KERNEL); - if (!stm32_dmamux) - return -ENOMEM; - - dma_req = 0; - for (i = 1; i <= count; i++) { - dma_node = of_parse_phandle(node, "dma-masters", i - 1); - - match = of_match_node(stm32_stm32dma_master_match, dma_node); - if (!match) { - dev_err(&pdev->dev, "DMA master is not supported\n"); - of_node_put(dma_node); - return -EINVAL; - } - - if (of_property_read_u32(dma_node, "dma-requests", - &stm32_dmamux->dma_reqs[i])) { - dev_info(&pdev->dev, - "Missing MUX output information, using %u.\n", - STM32_DMAMUX_MAX_DMA_REQUESTS); - stm32_dmamux->dma_reqs[i] = - STM32_DMAMUX_MAX_DMA_REQUESTS; - } - dma_req += stm32_dmamux->dma_reqs[i]; - of_node_put(dma_node); - } - - if (dma_req > STM32_DMAMUX_MAX_DMA_REQUESTS) { - dev_err(&pdev->dev, "Too many DMA Master Requests to manage\n"); - return -ENODEV; - } - - stm32_dmamux->dma_requests = dma_req; - stm32_dmamux->dma_reqs[0] = count; - stm32_dmamux->dma_inuse = devm_kcalloc(&pdev->dev, - BITS_TO_LONGS(dma_req), - sizeof(unsigned long), - GFP_KERNEL); - if (!stm32_dmamux->dma_inuse) - return -ENOMEM; - - if (device_property_read_u32(&pdev->dev, "dma-requests", - &stm32_dmamux->dmamux_requests)) { - stm32_dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS; - dev_warn(&pdev->dev, "DMAMUX defaulting on %u requests\n", - stm32_dmamux->dmamux_requests); - } - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - iomem = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(iomem)) - return PTR_ERR(iomem); - - spin_lock_init(&stm32_dmamux->lock); - - stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(stm32_dmamux->clk)) { - ret = PTR_ERR(stm32_dmamux->clk); - if (ret == -EPROBE_DEFER) - dev_info(&pdev->dev, "Missing controller clock\n"); - return ret; - } - - stm32_dmamux->rst = devm_reset_control_get(&pdev->dev, NULL); - if (!IS_ERR(stm32_dmamux->rst)) { - reset_control_assert(stm32_dmamux->rst); - udelay(2); - reset_control_deassert(stm32_dmamux->rst); - } - - stm32_dmamux->iomem = iomem; - stm32_dmamux->dmarouter.dev = &pdev->dev; - stm32_dmamux->dmarouter.route_free = stm32_dmamux_free; - - platform_set_drvdata(pdev, stm32_dmamux); - - if (!IS_ERR(stm32_dmamux->clk)) { - ret = clk_prepare_enable(stm32_dmamux->clk); - if (ret < 0) { - dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret); - return ret; - } - } - - /* Reset the dmamux */ - for (i = 0; i < stm32_dmamux->dma_requests; i++) - stm32_dmamux_write(stm32_dmamux->iomem, STM32_DMAMUX_CCR(i), 0); - - if (!IS_ERR(stm32_dmamux->clk)) - clk_disable(stm32_dmamux->clk); - - return of_dma_router_register(node, stm32_dmamux_route_allocate, - &stm32_dmamux->dmarouter); -} - -static const struct of_device_id stm32_dmamux_match[] = { - { .compatible = "st,stm32h7-dmamux" }, - {}, -}; - -static struct platform_driver stm32_dmamux_driver = { - .probe = stm32_dmamux_probe, - .driver = { - .name = "stm32-dmamux", - .of_match_table = stm32_dmamux_match, - }, -}; - -static int __init stm32_dmamux_init(void) -{ - return platform_driver_register(&stm32_dmamux_driver); -} -arch_initcall(stm32_dmamux_init); - -MODULE_DESCRIPTION("DMA Router driver for STM32 DMA MUX"); -MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>"); -MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>"); -MODULE_LICENSE("GPL v2"); |
