From patchwork Mon Mar 20 08:11:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ChiaWei Wang X-Patchwork-Id: 13181506 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 237D1C7619A for ; Mon, 20 Mar 2023 15:48:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=FSDTwySdJHmC26QcwQeINsRkrZNC72DHYhM9iQhx4po=; b=G5PDWKe7psMece uzniFUOlAMRbVyt0V/2S+/K4Le+MlFJ7VRDo0Z2ETKxKzbQkXWd3LQ0Yf1EiXFwK3ht8+YSIOeMCW +k4qd+vMd69p5iaTi/rFe4pz5qgWQ0Ps/iu9wQ+hS0GfkZ+ZuNVFW5WmFZyrgdTMMZQnUwGOhFaNP /EltfXQvjESFSoZOpCAu6L32eG7M777Uvf7+OUm+DeVK2kFeXxjp/TMrPLcVWmnfl5VLTYurXn4U0 KwSLJT/2ke7XOBNoCcn4crBlxH4Hz3U974p/Pc0HKDbprZMqeUfyFhtluoLQ9/2zlhmC0H/pVHsvv aDBdQkczNqdU3RycYXfw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1peHjw-009cpv-18; Mon, 20 Mar 2023 15:48:04 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1peHjc-009cid-2F for linux-arm-kernel@bombadil.infradead.org; Mon, 20 Mar 2023 15:47:44 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Content-Transfer-Encoding :MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:To:From:Sender: Reply-To:Cc:Content-ID:Content-Description; bh=mI7Q2Ztubjc2izqGVzS+whDNBthip2mSadY5B35UXco=; b=c6DXIalnAYR0Ig1uA4SGHlyNy+ K2iaeW3DQJyeVws3ypePz92+2x+b7/iw9Pv9UOBinWyXomzWD2BzSACkpOUydP1Ru94dbidQRo6Ms /U+8dHf+Brv/cfyvn7vjyVa8ZKNbDz6EDbsJM4P7FSz+iV2cR/op5WrmGmOaJMyx0W+qfajzlHr30 CIk2uW1aw4+w0oYM8XYtF7Fuv0TiUbwJFLWGSCcGvE9yQa2Us2a3AxyxuHbe1XX+YImKcKNg+Frig LYECGdvDxITzzjQZQ/09Uul6xVwRvvLiwigifQRUgK+BkWBgmCa+eEJbCUYnvAqqPQz088h0EHbpX mA+WdP7w==; Received: from twspam01.aspeedtech.com ([211.20.114.71]) by desiato.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1peAdC-003rLC-3B for linux-arm-kernel@lists.infradead.org; Mon, 20 Mar 2023 08:12:50 +0000 Received: from mail.aspeedtech.com ([192.168.0.24]) by twspam01.aspeedtech.com with ESMTP id 32K7v6wh088828; Mon, 20 Mar 2023 15:57:06 +0800 (GMT-8) (envelope-from chiawei_wang@aspeedtech.com) Received: from Chiawei-PC03.aspeed.com (192.168.2.66) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 20 Mar 2023 16:11:38 +0800 From: Chia-Wei Wang To: , , , , , , , , , , , , , , , , Subject: [PATCH v3 3/5] dmaengine: aspeed: Add AST2600 UART DMA driver Date: Mon, 20 Mar 2023 16:11:31 +0800 Message-ID: <20230320081133.23655-4-chiawei_wang@aspeedtech.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230320081133.23655-1-chiawei_wang@aspeedtech.com> References: <20230320081133.23655-1-chiawei_wang@aspeedtech.com> MIME-Version: 1.0 X-Originating-IP: [192.168.2.66] X-ClientProxiedBy: TWMBX02.aspeed.com (192.168.0.24) To TWMBX02.aspeed.com (192.168.0.24) X-DNSRBL: X-MAIL: twspam01.aspeedtech.com 32K7v6wh088828 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230320_081240_405767_9E3BFF2E X-CRM114-Status: GOOD ( 26.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Aspeed AST2600 UART DMA (UDMA) includes 28 channels for the DMA transmission and recevie of each UART devices. Signed-off-by: Chia-Wei Wang --- drivers/dma/Kconfig | 9 + drivers/dma/Makefile | 1 + drivers/dma/ast2600-udma.c | 534 +++++++++++++++++++++++++++++++++++++ 3 files changed, 544 insertions(+) create mode 100644 drivers/dma/ast2600-udma.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index fb7073fc034f..18bf6b1350d3 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -93,6 +93,15 @@ config APPLE_ADMAC help Enable support for Audio DMA Controller found on Apple Silicon SoCs. +config ASPEED_AST2600_UDMA + bool "Aspeed AST2600 UDMA support" + depends on ARCH_ASPEED || COMPILE_TEST + help + Enable support for Aspeed AST2600 UART DMA. Select this option if you + have a AST2600 SoC integrated system. The driver provides the UART DMA + support with the dmaengine subsystem, which can be leveraged by generic + 8250 serial drivers. + config AT_HDMAC tristate "Atmel AHB DMA support" depends on ARCH_AT91 diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index a4fd1ce29510..6cbacebcdcab 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_XGENE_DMA) += xgene-dma.o obj-$(CONFIG_ST_FDMA) += st_fdma.o obj-$(CONFIG_FSL_DPAA2_QDMA) += fsl-dpaa2-qdma/ obj-$(CONFIG_INTEL_LDMA) += lgm/ +obj-$(CONFIG_ASPEED_AST2600_UDMA) += ast2600-udma.o obj-y += mediatek/ obj-y += qcom/ diff --git a/drivers/dma/ast2600-udma.c b/drivers/dma/ast2600-udma.c new file mode 100644 index 000000000000..39117b26996d --- /dev/null +++ b/drivers/dma/ast2600-udma.c @@ -0,0 +1,534 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) ASPEED Technology Inc. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "dmaengine.h" + +#define DEVICE_NAME "aspeed-udma" + +/* register offset */ +#define UDMA_TX_EN 0x000 +#define UDMA_RX_EN 0x004 +#define UDMA_TMOUT 0x00c +#define UDMA_TX_PTR_RST 0x020 +#define UDMA_RX_PTR_RST 0x024 +#define UDMA_TX_INT_EN 0x030 +#define UDMA_TX_INT_STS 0x034 +#define UDMA_RX_INT_EN 0x038 +#define UDMA_RX_INT_STS 0x03c + +#define UDMA_CH_OFFS(x) ((x) * 0x10) +#define UDMA_CH_RPTR(x) (0x040 + UDMA_CH_OFFS(x)) +#define UDMA_CH_WPTR(x) (0x044 + UDMA_CH_OFFS(x)) +#define UDMA_CH_ADDR(x) (0x048 + UDMA_CH_OFFS(x)) +#define UDMA_CH_CTRL(x) (0x04c + UDMA_CH_OFFS(x)) +#define UDMA_CH_CTRL_BUFSZ GENMASK(1, 0) + +#define UDMA_MAX_BUFSZ (0x10000) +#define UDMA_MAX_TXSZ (UDMA_MAX_BUFSZ - 1) + +enum ast2600_udma_bufsz { + UDMA_BUFSZ_1KB, + UDMA_BUFSZ_4KB, + UDMA_BUFSZ_16KB, + UDMA_BUFSZ_64KB, +}; + +struct ast2600_udma_desc { + struct dma_async_tx_descriptor tx; + dma_addr_t addr; + unsigned int size; +}; + +struct ast2600_udma_chan { + struct dma_chan chan; + struct ast2600_udma_desc ud; + struct ast2600_udma *udma; + uint32_t residue; + + /* 4B-aligned local buffer for workaround */ + uint8_t *buf; + dma_addr_t buf_addr; + + bool is_tx; +}; + +struct ast2600_udma { + struct dma_device ddev; + uint8_t __iomem *regs; + int irq; + struct ast2600_udma_chan *ucs; + uint32_t n_ucs; + spinlock_t lock; +}; + +static struct ast2600_udma_chan *to_ast2600_udma_chan(struct dma_chan *chan) +{ + return container_of(chan, struct ast2600_udma_chan, chan); +} + +static int ast2600_udma_alloc_chan_resources(struct dma_chan *chan) +{ + dma_cookie_init(chan); + + return 0; +} + +static dma_cookie_t ast2600_udma_tx_submit(struct dma_async_tx_descriptor *tx) +{ + return dma_cookie_assign(tx); +} + +/* consider only 8250_dma using dmaengine_prep_slave_single() */ +static struct dma_async_tx_descriptor *ast2600_udma_prep_slave_sg(struct dma_chan *chan, + struct scatterlist *sgl, + unsigned int sg_len, + enum dma_transfer_direction dir, + unsigned long tx_flags, + void *context) +{ + struct device *dev = chan->device->dev; + struct ast2600_udma_chan *uc = to_ast2600_udma_chan(chan); + struct ast2600_udma_desc *ud = &uc->ud; + phys_addr_t pa; + void *va; + + if (!is_slave_direction(dir)) { + dev_err(dev, "direction is not slave mode\n"); + return NULL; + } + + if (sg_len != 1) { + dev_err(dev, "scatter list length is not 1\n"); + return NULL; + } + + if (uc->is_tx && dir != DMA_MEM_TO_DEV) { + dev_err(dev, "invalid direction to TX channel\n"); + return NULL; + } + + ud->addr = sg_dma_address(sgl); + ud->size = sg_dma_len(sgl); + + if (uc->is_tx) { + if (ud->size > UDMA_MAX_TXSZ) { + dev_err(dev, "invalid TX DMA SIZE"); + return NULL; + } + + /* + * UDMA is limited to 4B-aligned DMA addresses. + * Thus copy data to local 4B-aligned buffer if + * the source does not fit. + */ + if (ud->addr & 0x3) { + pa = dma_to_phys(chan->device->dev, ud->addr); + if (pa != (phys_addr_t)-1) { + va = phys_to_virt(pa); + memcpy(uc->buf, va, ud->size); + ud->addr = uc->buf_addr; + } + } + } else { + /* + * UDMA RX buffer size is limited to 1/4/16/64 KB + * We use the lower bits to encode the buffer size + */ + switch (ud->size) { + case 0x400: + ud->size |= FIELD_PREP(UDMA_CH_CTRL_BUFSZ, UDMA_BUFSZ_1KB); + break; + case 0x1000: + ud->size |= FIELD_PREP(UDMA_CH_CTRL_BUFSZ, UDMA_BUFSZ_4KB); + break; + case 0x4000: + ud->size |= FIELD_PREP(UDMA_CH_CTRL_BUFSZ, UDMA_BUFSZ_16KB); + break; + case 0x10000: + ud->size |= FIELD_PREP(UDMA_CH_CTRL_BUFSZ, UDMA_BUFSZ_64KB); + break; + default: + dev_err(dev, "invalid RX DMA size\n"); + return NULL; + } + } + + dma_async_tx_descriptor_init(&ud->tx, &uc->chan); + ud->tx.tx_submit = ast2600_udma_tx_submit; + + return &ud->tx; +} + +static void ast2600_udma_issue_pending(struct dma_chan *chan) +{ + unsigned long flags; + uint32_t r_pr, r_is, r_ie, r_en, reg; + uint32_t ch_id = chan->chan_id; + uint32_t ch_bit = ch_id / 2; + dma_addr_t rx_addr; + uint32_t rx_size; + struct ast2600_udma_chan *uc = to_ast2600_udma_chan(chan); + struct ast2600_udma_desc *ud = &uc->ud; + struct ast2600_udma *udma = uc->udma; + + if (uc->is_tx) { + r_pr = UDMA_TX_PTR_RST; + r_is = UDMA_TX_INT_STS; + r_ie = UDMA_TX_INT_EN; + r_en = UDMA_TX_EN; + } else { + r_pr = UDMA_RX_PTR_RST; + r_is = UDMA_RX_INT_STS; + r_ie = UDMA_RX_INT_EN; + r_en = UDMA_RX_EN; + } + + spin_lock_irqsave(&udma->lock, flags); + + /* reset channel HW read/write pointer */ + writel(BIT(ch_bit), udma->regs + r_pr); + writel(0, udma->regs + r_pr); + + /* clear interrupt status */ + writel(BIT(ch_bit), udma->regs + r_is); + + /* set transfer address & size */ + if (uc->is_tx) { + writel(ud->addr, udma->regs + UDMA_CH_ADDR(ch_id)); + writel(ud->size, udma->regs + UDMA_CH_WPTR(ch_id)); + writel(UDMA_BUFSZ_64KB, udma->regs + UDMA_CH_CTRL(ch_id)); + } else { + /* + * UDMA is limited to 4B-aligned addresses. + * Thus use local 4B-aligned buffer to get + * RX data and copy to the real destination + * after then. + */ + rx_addr = (ud->addr & 0x3) ? uc->buf_addr : ud->addr; + rx_size = FIELD_GET(UDMA_CH_CTRL_BUFSZ, ud->size); + writel(rx_addr, udma->regs + UDMA_CH_ADDR(ch_id)); + writel(rx_size, udma->regs + UDMA_CH_CTRL(ch_id)); + } + + /* enable interrupt */ + reg = readl(udma->regs + r_ie) | BIT(ch_bit); + writel(reg, udma->regs + r_ie); + + /* start DMA */ + reg = readl(udma->regs + r_en) | BIT(ch_bit); + writel(reg, udma->regs + r_en); + + spin_unlock_irqrestore(&udma->lock, flags); +} + +static enum dma_status ast2600_udma_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, struct dma_tx_state *txstate) +{ + struct ast2600_udma_chan *uc = to_ast2600_udma_chan(chan); + enum dma_status sts = dma_cookie_status(chan, cookie, txstate); + + dma_set_residue(txstate, uc->residue); + + return sts; +} + +static int ast2600_udma_pause(struct dma_chan *chan) +{ + unsigned long flags; + uint32_t r_en, r_ie, reg; + uint32_t ch_id = chan->chan_id; + uint32_t ch_bit = ch_id / 2; + struct ast2600_udma_chan *uc = to_ast2600_udma_chan(chan); + struct ast2600_udma *udma = uc->udma; + + if (uc->is_tx) { + r_en = UDMA_TX_EN; + r_ie = UDMA_TX_INT_EN; + } else { + r_en = UDMA_RX_EN; + r_ie = UDMA_RX_INT_EN; + } + + spin_lock_irqsave(&udma->lock, flags); + + reg = readl(udma->regs + r_en) & ~BIT(ch_bit); + writel(reg, udma->regs + r_en); + + reg = readl(udma->regs + r_ie) & ~BIT(ch_bit); + writel(reg, udma->regs + r_ie); + + spin_unlock_irqrestore(&udma->lock, flags); + + return 0; +} + +static int ast2600_udma_resume(struct dma_chan *chan) +{ + unsigned long flags; + uint32_t r_en, r_ie, reg; + uint32_t ch_id = chan->chan_id; + uint32_t ch_bit = ch_id / 2; + struct ast2600_udma_chan *uc = to_ast2600_udma_chan(chan); + struct ast2600_udma *udma = uc->udma; + + if (uc->is_tx) { + r_en = UDMA_TX_EN; + r_ie = UDMA_TX_INT_EN; + } else { + r_en = UDMA_RX_EN; + r_ie = UDMA_RX_INT_EN; + } + + spin_lock_irqsave(&udma->lock, flags); + + reg = readl(udma->regs + r_en) | BIT(ch_bit); + writel(reg, udma->regs + r_en); + + reg = readl(udma->regs + r_ie) | BIT(ch_bit); + writel(reg, udma->regs + r_ie); + + spin_unlock_irqrestore(&udma->lock, flags); + + return 0; +} + +static int ast2600_udma_terminate(struct dma_chan *chan) +{ + unsigned long flags; + uint32_t r_pr, r_is, r_ie, r_en, reg; + uint32_t ch_id = chan->chan_id; + uint32_t ch_bit = ch_id / 2; + struct ast2600_udma_chan *uc = to_ast2600_udma_chan(chan); + struct ast2600_udma *udma = uc->udma; + + if (uc->is_tx) { + r_pr = UDMA_TX_PTR_RST; + r_is = UDMA_TX_INT_STS; + r_ie = UDMA_TX_INT_EN; + r_en = UDMA_TX_EN; + } else { + r_pr = UDMA_RX_PTR_RST; + r_is = UDMA_RX_INT_STS; + r_ie = UDMA_RX_INT_EN; + r_en = UDMA_RX_EN; + } + + spin_lock_irqsave(&udma->lock, flags); + + /* disable DMA */ + reg = readl(udma->regs + r_en) & ~BIT(ch_bit); + writel(reg, udma->regs + r_en); + + /* disable interrupt */ + reg = readl(udma->regs + r_ie) & ~BIT(ch_bit); + writel(reg, udma->regs + r_ie); + + /* clear interrupt status */ + writel(BIT(ch_bit), udma->regs + r_is); + + /* reset channel HW read/write pointer */ + writel(BIT(ch_bit), udma->regs + r_pr); + writel(0, udma->regs + r_pr); + + spin_unlock_irqrestore(&udma->lock, flags); + + return 0; +} + +static irqreturn_t ast2600_udma_isr(int irq, void *arg) +{ + struct ast2600_udma *udma = arg; + struct ast2600_udma_chan *uc; + struct ast2600_udma_desc *ud; + struct dma_async_tx_descriptor *tx; + uint32_t sts, rptr, wptr; + uint32_t ch_id, ch_bit; + phys_addr_t pa; + void *va; + + /* handle TX interrupt */ + sts = readl(udma->regs + UDMA_TX_INT_STS); + for_each_set_bit(ch_bit, (unsigned long *)&sts, (udma->n_ucs / 2)) { + ch_id = ch_bit << 1; + rptr = readl(udma->regs + UDMA_CH_RPTR(ch_id)); + wptr = readl(udma->regs + UDMA_CH_WPTR(ch_id)); + + uc = &udma->ucs[ch_id]; + uc->residue = wptr - rptr; + + ast2600_udma_terminate(&uc->chan); + + tx = &uc->ud.tx; + dma_cookie_complete(tx); + dma_descriptor_unmap(tx); + dmaengine_desc_get_callback_invoke(tx, NULL); + } + + /* handle RX interrupt */ + sts = readl(udma->regs + UDMA_RX_INT_STS); + for_each_set_bit(ch_bit, (unsigned long *)&sts, udma->n_ucs / 2) { + ch_id = (ch_bit << 1) + 1; + wptr = readl(udma->regs + UDMA_CH_WPTR(ch_id)); + + uc = &udma->ucs[ch_id]; + ud = &uc->ud; + tx = &ud->tx; + + uc->residue = (ud->size & ~UDMA_CH_CTRL_BUFSZ) - wptr; + + /* handle non-4B-aligned case */ + if (ud->addr & 0x3) { + pa = dma_to_phys(uc->chan.device->dev, ud->addr); + if (pa != (phys_addr_t)-1) { + va = phys_to_virt(pa); + memcpy(va, uc->buf, wptr); + } + } + + ast2600_udma_terminate(&uc->chan); + + dma_cookie_complete(tx); + dma_descriptor_unmap(tx); + dmaengine_desc_get_callback_invoke(tx, NULL); + } + + return IRQ_HANDLED; +} + +static int ast2600_udma_probe(struct platform_device *pdev) +{ + int i, rc; + struct resource *res; + struct ast2600_udma *udma; + struct device *dev = &pdev->dev; + + udma = devm_kzalloc(dev, sizeof(*udma), GFP_KERNEL); + if (!udma) + return -ENOMEM; + + dma_cap_set(DMA_SLAVE, udma->ddev.cap_mask); + udma->ddev.device_alloc_chan_resources = ast2600_udma_alloc_chan_resources; + udma->ddev.device_prep_slave_sg = ast2600_udma_prep_slave_sg; + udma->ddev.device_issue_pending = ast2600_udma_issue_pending; + udma->ddev.device_tx_status = ast2600_udma_tx_status; + udma->ddev.device_pause = ast2600_udma_pause; + udma->ddev.device_resume = ast2600_udma_resume; + udma->ddev.device_terminate_all = ast2600_udma_terminate; + udma->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE); + udma->ddev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE); + udma->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + udma->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + udma->ddev.dev = dev; + INIT_LIST_HEAD(&udma->ddev.channels); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (IS_ERR(res)) { + dev_err(dev, "cannot get IO resource\n"); + return -ENODEV; + } + + udma->regs = devm_ioremap_resource(dev, res); + if (IS_ERR(udma->regs)) { + dev_err(dev, "cannot map IO registers\n"); + return PTR_ERR(udma->regs); + } + + /* timeout value: 0x200 * (PCLK * 14400) */ + writel(0x200, udma->regs + UDMA_TMOUT); + + /* disable all for safety */ + writel(0x0, udma->regs + UDMA_TX_EN); + writel(0x0, udma->regs + UDMA_RX_EN); + + udma->irq = platform_get_irq(pdev, 0); + if (udma->irq < 0) + return udma->irq; + + rc = devm_request_irq(&pdev->dev, udma->irq, ast2600_udma_isr, + IRQF_SHARED, DEVICE_NAME, udma); + if (rc) { + dev_err(dev, "cannot request IRQ\n"); + return rc; + } + + rc = of_property_read_u32(dev->of_node, "dma-channels", &udma->n_ucs); + if (rc) { + dev_err(dev, "cannot find number of channels\n"); + return rc; + } + + udma->ucs = devm_kzalloc(dev, + sizeof(struct ast2600_udma_chan) * udma->n_ucs, GFP_KERNEL); + if (!udma->ucs) + return -ENOMEM; + + for (i = 0; i < udma->n_ucs; ++i) { + udma->ucs[i].is_tx = !(i % 2); + udma->ucs[i].chan.device = &udma->ddev; + udma->ucs[i].buf = dmam_alloc_coherent(dev, UDMA_MAX_BUFSZ, + &udma->ucs[i].buf_addr, GFP_KERNEL); + if (!udma->ucs[i].buf) + return -ENOMEM; + + udma->ucs[i].udma = udma; + list_add_tail(&udma->ucs[i].chan.device_node, &udma->ddev.channels); + } + + rc = dma_async_device_register(&udma->ddev); + if (rc) + return rc; + + rc = of_dma_controller_register(dev->of_node, of_dma_xlate_by_chan_id, &udma->ddev); + if (rc) + return rc; + + spin_lock_init(&udma->lock); + + platform_set_drvdata(pdev, udma); + + dev_info(dev, "module loaded\n"); + + return 0; +} + +static int ast2600_udma_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct ast2600_udma *udma = platform_get_drvdata(pdev); + + of_dma_controller_free(dev->of_node); + dma_async_device_unregister(&udma->ddev); + + dev_info(dev, "module removed\n"); + + return 0; +} + +static const struct of_device_id ast2600_udma_match[] = { + { .compatible = "aspeed,ast2600-udma" }, + { }, +}; + +static struct platform_driver ast2600_udma_driver = { + .probe = ast2600_udma_probe, + .remove = ast2600_udma_remove, + .driver = { + .name = DEVICE_NAME, + .of_match_table = ast2600_udma_match, + }, +}; + +module_platform_driver(ast2600_udma_driver); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Chia-Wei Wang