diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-01-20 14:01:31 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-01-20 14:01:31 -0300 |
commit | b4b7ff4b08e691656c9d77c758fc355833128ac0 (patch) | |
tree | 82fcb00e6b918026dc9f2d1f05ed8eee83874cc0 /arch/powerpc/platforms/512x | |
parent | 35acfa0fc609f2a2cd95cef4a6a9c3a5c38f1778 (diff) |
Linux-libre 4.4-gnupck-4.4-gnu
Diffstat (limited to 'arch/powerpc/platforms/512x')
-rw-r--r-- | arch/powerpc/platforms/512x/Kconfig | 6 | ||||
-rw-r--r-- | arch/powerpc/platforms/512x/Makefile | 1 | ||||
-rw-r--r-- | arch/powerpc/platforms/512x/mpc512x_lpbfifo.c | 540 |
3 files changed, 547 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/512x/Kconfig b/arch/powerpc/platforms/512x/Kconfig index 48bf38d0d..f09016f6b 100644 --- a/arch/powerpc/platforms/512x/Kconfig +++ b/arch/powerpc/platforms/512x/Kconfig @@ -10,6 +10,12 @@ config PPC_MPC512x select USB_EHCI_BIG_ENDIAN_MMIO if USB_EHCI_HCD select USB_EHCI_BIG_ENDIAN_DESC if USB_EHCI_HCD +config MPC512x_LPBFIFO + tristate "MPC512x LocalPlus Bus FIFO driver" + depends on PPC_MPC512x && MPC512X_DMA + help + Enable support for Freescale MPC512x LocalPlus Bus FIFO (SCLPC). + config MPC5121_ADS bool "Freescale MPC5121E ADS" depends on PPC_MPC512x diff --git a/arch/powerpc/platforms/512x/Makefile b/arch/powerpc/platforms/512x/Makefile index 01693121a..f47d42295 100644 --- a/arch/powerpc/platforms/512x/Makefile +++ b/arch/powerpc/platforms/512x/Makefile @@ -5,4 +5,5 @@ obj-$(CONFIG_COMMON_CLK) += clock-commonclk.o obj-y += mpc512x_shared.o obj-$(CONFIG_MPC5121_ADS) += mpc5121_ads.o mpc5121_ads_cpld.o obj-$(CONFIG_MPC512x_GENERIC) += mpc512x_generic.o +obj-$(CONFIG_MPC512x_LPBFIFO) += mpc512x_lpbfifo.o obj-$(CONFIG_PDM360NG) += pdm360ng.o diff --git a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c new file mode 100644 index 000000000..8eb82b043 --- /dev/null +++ b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c @@ -0,0 +1,540 @@ +/* + * The driver for Freescale MPC512x LocalPlus Bus FIFO + * (called SCLPC in the Reference Manual). + * + * Copyright (C) 2013-2015 Alexander Popov <alex.popov@linux.com>. + * + * This file is released under the GPLv2. + */ + +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <asm/mpc5121.h> +#include <asm/io.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/dmaengine.h> +#include <linux/dma-direction.h> +#include <linux/dma-mapping.h> + +#define DRV_NAME "mpc512x_lpbfifo" + +struct cs_range { + u32 csnum; + u32 base; /* must be zero */ + u32 addr; + u32 size; +}; + +static struct lpbfifo_data { + spinlock_t lock; /* for protecting lpbfifo_data */ + phys_addr_t regs_phys; + resource_size_t regs_size; + struct mpc512x_lpbfifo __iomem *regs; + int irq; + struct cs_range *cs_ranges; + size_t cs_n; + struct dma_chan *chan; + struct mpc512x_lpbfifo_request *req; + dma_addr_t ram_bus_addr; + bool wait_lpbfifo_irq; + bool wait_lpbfifo_callback; +} lpbfifo; + +/* + * A data transfer from RAM to some device on LPB is finished + * when both mpc512x_lpbfifo_irq() and mpc512x_lpbfifo_callback() + * have been called. We execute the callback registered in + * mpc512x_lpbfifo_request just after that. + * But for a data transfer from some device on LPB to RAM we don't enable + * LPBFIFO interrupt because clearing MPC512X_SCLPC_SUCCESS interrupt flag + * automatically disables LPBFIFO reading request to the DMA controller + * and the data transfer hangs. So the callback registered in + * mpc512x_lpbfifo_request is executed at the end of mpc512x_lpbfifo_callback(). + */ + +/* + * mpc512x_lpbfifo_irq - IRQ handler for LPB FIFO + */ +static irqreturn_t mpc512x_lpbfifo_irq(int irq, void *param) +{ + struct device *dev = (struct device *)param; + struct mpc512x_lpbfifo_request *req = NULL; + unsigned long flags; + u32 status; + + spin_lock_irqsave(&lpbfifo.lock, flags); + + if (!lpbfifo.regs) + goto end; + + req = lpbfifo.req; + if (!req || req->dir == MPC512X_LPBFIFO_REQ_DIR_READ) { + dev_err(dev, "bogus LPBFIFO IRQ\n"); + goto end; + } + + status = in_be32(&lpbfifo.regs->status); + if (status != MPC512X_SCLPC_SUCCESS) { + dev_err(dev, "DMA transfer from RAM to peripheral failed\n"); + out_be32(&lpbfifo.regs->enable, + MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET); + goto end; + } + /* Clear the interrupt flag */ + out_be32(&lpbfifo.regs->status, MPC512X_SCLPC_SUCCESS); + + lpbfifo.wait_lpbfifo_irq = false; + + if (lpbfifo.wait_lpbfifo_callback) + goto end; + + /* Transfer is finished, set the FIFO as idle */ + lpbfifo.req = NULL; + + spin_unlock_irqrestore(&lpbfifo.lock, flags); + + if (req->callback) + req->callback(req); + + return IRQ_HANDLED; + + end: + spin_unlock_irqrestore(&lpbfifo.lock, flags); + return IRQ_HANDLED; +} + +/* + * mpc512x_lpbfifo_callback is called by DMA driver when + * DMA transaction is finished. + */ +static void mpc512x_lpbfifo_callback(void *param) +{ + unsigned long flags; + struct mpc512x_lpbfifo_request *req = NULL; + enum dma_data_direction dir; + + spin_lock_irqsave(&lpbfifo.lock, flags); + + if (!lpbfifo.regs) { + spin_unlock_irqrestore(&lpbfifo.lock, flags); + return; + } + + req = lpbfifo.req; + if (!req) { + pr_err("bogus LPBFIFO callback\n"); + spin_unlock_irqrestore(&lpbfifo.lock, flags); + return; + } + + /* Release the mapping */ + if (req->dir == MPC512X_LPBFIFO_REQ_DIR_WRITE) + dir = DMA_TO_DEVICE; + else + dir = DMA_FROM_DEVICE; + dma_unmap_single(lpbfifo.chan->device->dev, + lpbfifo.ram_bus_addr, req->size, dir); + + lpbfifo.wait_lpbfifo_callback = false; + + if (!lpbfifo.wait_lpbfifo_irq) { + /* Transfer is finished, set the FIFO as idle */ + lpbfifo.req = NULL; + + spin_unlock_irqrestore(&lpbfifo.lock, flags); + + if (req->callback) + req->callback(req); + } else { + spin_unlock_irqrestore(&lpbfifo.lock, flags); + } +} + +static int mpc512x_lpbfifo_kick(void) +{ + u32 bits; + bool no_incr = false; + u32 bpt = 32; /* max bytes per LPBFIFO transaction involving DMA */ + u32 cs = 0; + size_t i; + struct dma_device *dma_dev = NULL; + struct scatterlist sg; + enum dma_data_direction dir; + struct dma_slave_config dma_conf = {}; + struct dma_async_tx_descriptor *dma_tx = NULL; + dma_cookie_t cookie; + int ret; + + /* + * 1. Fit the requirements: + * - the packet size must be a multiple of 4 since FIFO Data Word + * Register allows only full-word access according the Reference + * Manual; + * - the physical address of the device on LPB and the packet size + * must be aligned on BPT (bytes per transaction) or 8-bytes + * boundary according the Reference Manual; + * - but we choose DMA maxburst equal (or very close to) BPT to prevent + * DMA controller from overtaking FIFO and causing FIFO underflow + * error. So we force the packet size to be aligned on BPT boundary + * not to confuse DMA driver which requires the packet size to be + * aligned on maxburst boundary; + * - BPT should be set to the LPB device port size for operation with + * disabled auto-incrementing according Reference Manual. + */ + if (lpbfifo.req->size == 0 || !IS_ALIGNED(lpbfifo.req->size, 4)) + return -EINVAL; + + if (lpbfifo.req->portsize != LPB_DEV_PORTSIZE_UNDEFINED) { + bpt = lpbfifo.req->portsize; + no_incr = true; + } + + while (bpt > 1) { + if (IS_ALIGNED(lpbfifo.req->dev_phys_addr, min(bpt, 0x8u)) && + IS_ALIGNED(lpbfifo.req->size, bpt)) { + break; + } + + if (no_incr) + return -EINVAL; + + bpt >>= 1; + } + dma_conf.dst_maxburst = max(bpt, 0x4u) / 4; + dma_conf.src_maxburst = max(bpt, 0x4u) / 4; + + for (i = 0; i < lpbfifo.cs_n; i++) { + phys_addr_t cs_start = lpbfifo.cs_ranges[i].addr; + phys_addr_t cs_end = cs_start + lpbfifo.cs_ranges[i].size; + phys_addr_t access_start = lpbfifo.req->dev_phys_addr; + phys_addr_t access_end = access_start + lpbfifo.req->size; + + if (access_start >= cs_start && access_end <= cs_end) { + cs = lpbfifo.cs_ranges[i].csnum; + break; + } + } + if (i == lpbfifo.cs_n) + return -EFAULT; + + /* 2. Prepare DMA */ + dma_dev = lpbfifo.chan->device; + + if (lpbfifo.req->dir == MPC512X_LPBFIFO_REQ_DIR_WRITE) { + dir = DMA_TO_DEVICE; + dma_conf.direction = DMA_MEM_TO_DEV; + dma_conf.dst_addr = lpbfifo.regs_phys + + offsetof(struct mpc512x_lpbfifo, data_word); + } else { + dir = DMA_FROM_DEVICE; + dma_conf.direction = DMA_DEV_TO_MEM; + dma_conf.src_addr = lpbfifo.regs_phys + + offsetof(struct mpc512x_lpbfifo, data_word); + } + dma_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + dma_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + + /* Make DMA channel work with LPB FIFO data register */ + if (dma_dev->device_config(lpbfifo.chan, &dma_conf)) { + ret = -EINVAL; + goto err_dma_prep; + } + + sg_init_table(&sg, 1); + + sg_dma_address(&sg) = dma_map_single(dma_dev->dev, + lpbfifo.req->ram_virt_addr, lpbfifo.req->size, dir); + if (dma_mapping_error(dma_dev->dev, sg_dma_address(&sg))) + return -EFAULT; + + lpbfifo.ram_bus_addr = sg_dma_address(&sg); /* For freeing later */ + + sg_dma_len(&sg) = lpbfifo.req->size; + + dma_tx = dmaengine_prep_slave_sg(lpbfifo.chan, &sg, + 1, dma_conf.direction, 0); + if (!dma_tx) { + ret = -ENOSPC; + goto err_dma_prep; + } + dma_tx->callback = mpc512x_lpbfifo_callback; + dma_tx->callback_param = NULL; + + /* 3. Prepare FIFO */ + out_be32(&lpbfifo.regs->enable, + MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET); + out_be32(&lpbfifo.regs->enable, 0x0); + + /* + * Configure the watermarks for write operation (RAM->DMA->FIFO->dev): + * - high watermark 7 words according the Reference Manual, + * - low watermark 512 bytes (half of the FIFO). + * These watermarks don't work for read operation since the + * MPC512X_SCLPC_FLUSH bit is set (according the Reference Manual). + */ + out_be32(&lpbfifo.regs->fifo_ctrl, MPC512X_SCLPC_FIFO_CTRL(0x7)); + out_be32(&lpbfifo.regs->fifo_alarm, MPC512X_SCLPC_FIFO_ALARM(0x200)); + + /* + * Start address is a physical address of the region which belongs + * to the device on the LocalPlus Bus + */ + out_be32(&lpbfifo.regs->start_addr, lpbfifo.req->dev_phys_addr); + + /* + * Configure chip select, transfer direction, address increment option + * and bytes per transaction option + */ + bits = MPC512X_SCLPC_CS(cs); + if (lpbfifo.req->dir == MPC512X_LPBFIFO_REQ_DIR_READ) + bits |= MPC512X_SCLPC_READ | MPC512X_SCLPC_FLUSH; + if (no_incr) + bits |= MPC512X_SCLPC_DAI; + bits |= MPC512X_SCLPC_BPT(bpt); + out_be32(&lpbfifo.regs->ctrl, bits); + + /* Unmask irqs */ + bits = MPC512X_SCLPC_ENABLE | MPC512X_SCLPC_ABORT_INT_ENABLE; + if (lpbfifo.req->dir == MPC512X_LPBFIFO_REQ_DIR_WRITE) + bits |= MPC512X_SCLPC_NORM_INT_ENABLE; + else + lpbfifo.wait_lpbfifo_irq = false; + + out_be32(&lpbfifo.regs->enable, bits); + + /* 4. Set packet size and kick FIFO off */ + bits = lpbfifo.req->size | MPC512X_SCLPC_START; + out_be32(&lpbfifo.regs->pkt_size, bits); + + /* 5. Finally kick DMA off */ + cookie = dma_tx->tx_submit(dma_tx); + if (dma_submit_error(cookie)) { + ret = -ENOSPC; + goto err_dma_submit; + } + + return 0; + + err_dma_submit: + out_be32(&lpbfifo.regs->enable, + MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET); + err_dma_prep: + dma_unmap_single(dma_dev->dev, sg_dma_address(&sg), + lpbfifo.req->size, dir); + return ret; +} + +static int mpc512x_lpbfifo_submit_locked(struct mpc512x_lpbfifo_request *req) +{ + int ret = 0; + + if (!lpbfifo.regs) + return -ENODEV; + + /* Check whether a transfer is in progress */ + if (lpbfifo.req) + return -EBUSY; + + lpbfifo.wait_lpbfifo_irq = true; + lpbfifo.wait_lpbfifo_callback = true; + lpbfifo.req = req; + + ret = mpc512x_lpbfifo_kick(); + if (ret != 0) + lpbfifo.req = NULL; /* Set the FIFO as idle */ + + return ret; +} + +int mpc512x_lpbfifo_submit(struct mpc512x_lpbfifo_request *req) +{ + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&lpbfifo.lock, flags); + ret = mpc512x_lpbfifo_submit_locked(req); + spin_unlock_irqrestore(&lpbfifo.lock, flags); + + return ret; +} +EXPORT_SYMBOL(mpc512x_lpbfifo_submit); + +/* + * LPBFIFO driver uses "ranges" property of "localbus" device tree node + * for being able to determine the chip select number of a client device + * ordering a DMA transfer. + */ +static int get_cs_ranges(struct device *dev) +{ + int ret = -ENODEV; + struct device_node *lb_node; + const u32 *addr_cells_p; + const u32 *size_cells_p; + int proplen; + size_t i; + + lb_node = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-localbus"); + if (!lb_node) + return ret; + + /* + * The node defined as compatible with 'fsl,mpc5121-localbus' + * should have two address cells and one size cell. + * Every item of its ranges property should consist of: + * - the first address cell which is the chipselect number; + * - the second address cell which is the offset in the chipselect, + * must be zero. + * - CPU address of the beginning of an access window; + * - the only size cell which is the size of an access window. + */ + addr_cells_p = of_get_property(lb_node, "#address-cells", NULL); + size_cells_p = of_get_property(lb_node, "#size-cells", NULL); + if (addr_cells_p == NULL || *addr_cells_p != 2 || + size_cells_p == NULL || *size_cells_p != 1) { + goto end; + } + + proplen = of_property_count_u32_elems(lb_node, "ranges"); + if (proplen <= 0 || proplen % 4 != 0) + goto end; + + lpbfifo.cs_n = proplen / 4; + lpbfifo.cs_ranges = devm_kcalloc(dev, lpbfifo.cs_n, + sizeof(struct cs_range), GFP_KERNEL); + if (!lpbfifo.cs_ranges) + goto end; + + if (of_property_read_u32_array(lb_node, "ranges", + (u32 *)lpbfifo.cs_ranges, proplen) != 0) { + goto end; + } + + for (i = 0; i < lpbfifo.cs_n; i++) { + if (lpbfifo.cs_ranges[i].base != 0) + goto end; + } + + ret = 0; + + end: + of_node_put(lb_node); + return ret; +} + +static int mpc512x_lpbfifo_probe(struct platform_device *pdev) +{ + struct resource r; + int ret = 0; + + memset(&lpbfifo, 0, sizeof(struct lpbfifo_data)); + spin_lock_init(&lpbfifo.lock); + + lpbfifo.chan = dma_request_slave_channel(&pdev->dev, "rx-tx"); + if (lpbfifo.chan == NULL) + return -EPROBE_DEFER; + + if (of_address_to_resource(pdev->dev.of_node, 0, &r) != 0) { + dev_err(&pdev->dev, "bad 'reg' in 'sclpc' device tree node\n"); + ret = -ENODEV; + goto err0; + } + + lpbfifo.regs_phys = r.start; + lpbfifo.regs_size = resource_size(&r); + + if (!devm_request_mem_region(&pdev->dev, lpbfifo.regs_phys, + lpbfifo.regs_size, DRV_NAME)) { + dev_err(&pdev->dev, "unable to request region\n"); + ret = -EBUSY; + goto err0; + } + + lpbfifo.regs = devm_ioremap(&pdev->dev, + lpbfifo.regs_phys, lpbfifo.regs_size); + if (!lpbfifo.regs) { + dev_err(&pdev->dev, "mapping registers failed\n"); + ret = -ENOMEM; + goto err0; + } + + out_be32(&lpbfifo.regs->enable, + MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET); + + if (get_cs_ranges(&pdev->dev) != 0) { + dev_err(&pdev->dev, "bad '/localbus' device tree node\n"); + ret = -ENODEV; + goto err0; + } + + lpbfifo.irq = irq_of_parse_and_map(pdev->dev.of_node, 0); + if (lpbfifo.irq == NO_IRQ) { + dev_err(&pdev->dev, "mapping irq failed\n"); + ret = -ENODEV; + goto err0; + } + + if (request_irq(lpbfifo.irq, mpc512x_lpbfifo_irq, 0, + DRV_NAME, &pdev->dev) != 0) { + dev_err(&pdev->dev, "requesting irq failed\n"); + ret = -ENODEV; + goto err1; + } + + dev_info(&pdev->dev, "probe succeeded\n"); + return 0; + + err1: + irq_dispose_mapping(lpbfifo.irq); + err0: + dma_release_channel(lpbfifo.chan); + return ret; +} + +static int mpc512x_lpbfifo_remove(struct platform_device *pdev) +{ + unsigned long flags; + struct dma_device *dma_dev = lpbfifo.chan->device; + struct mpc512x_lpbfifo __iomem *regs = NULL; + + spin_lock_irqsave(&lpbfifo.lock, flags); + regs = lpbfifo.regs; + lpbfifo.regs = NULL; + spin_unlock_irqrestore(&lpbfifo.lock, flags); + + dma_dev->device_terminate_all(lpbfifo.chan); + out_be32(®s->enable, MPC512X_SCLPC_RESET | MPC512X_SCLPC_FIFO_RESET); + + free_irq(lpbfifo.irq, &pdev->dev); + irq_dispose_mapping(lpbfifo.irq); + dma_release_channel(lpbfifo.chan); + + return 0; +} + +static const struct of_device_id mpc512x_lpbfifo_match[] = { + { .compatible = "fsl,mpc512x-lpbfifo", }, + {}, +}; +MODULE_DEVICE_TABLE(of, mpc512x_lpbfifo_match); + +static struct platform_driver mpc512x_lpbfifo_driver = { + .probe = mpc512x_lpbfifo_probe, + .remove = mpc512x_lpbfifo_remove, + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + .of_match_table = mpc512x_lpbfifo_match, + }, +}; + +module_platform_driver(mpc512x_lpbfifo_driver); + +MODULE_AUTHOR("Alexander Popov <alex.popov@linux.com>"); +MODULE_DESCRIPTION("MPC512x LocalPlus Bus FIFO device driver"); +MODULE_LICENSE("GPL v2"); |