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linux/drivers/fpga/zynq-fpga.c

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/*
* Copyright (c) 2011-2015 Xilinx Inc.
* Copyright (c) 2015, National Instruments Corp.
*
* FPGA Manager Driver for Xilinx Zynq, heavily based on xdevcfg driver
* in their vendor tree.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* 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.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/fpga/fpga-mgr.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/mfd/syscon.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/pm.h>
#include <linux/regmap.h>
#include <linux/string.h>
#include <linux/scatterlist.h>
/* Offsets into SLCR regmap */
/* FPGA Software Reset Control */
#define SLCR_FPGA_RST_CTRL_OFFSET 0x240
/* Level Shifters Enable */
#define SLCR_LVL_SHFTR_EN_OFFSET 0x900
/* Constant Definitions */
/* Control Register */
#define CTRL_OFFSET 0x00
/* Lock Register */
#define LOCK_OFFSET 0x04
/* Interrupt Status Register */
#define INT_STS_OFFSET 0x0c
/* Interrupt Mask Register */
#define INT_MASK_OFFSET 0x10
/* Status Register */
#define STATUS_OFFSET 0x14
/* DMA Source Address Register */
#define DMA_SRC_ADDR_OFFSET 0x18
/* DMA Destination Address Reg */
#define DMA_DST_ADDR_OFFSET 0x1c
/* DMA Source Transfer Length */
#define DMA_SRC_LEN_OFFSET 0x20
/* DMA Destination Transfer */
#define DMA_DEST_LEN_OFFSET 0x24
/* Unlock Register */
#define UNLOCK_OFFSET 0x34
/* Misc. Control Register */
#define MCTRL_OFFSET 0x80
/* Control Register Bit definitions */
/* Signal to reset FPGA */
#define CTRL_PCFG_PROG_B_MASK BIT(30)
/* Enable PCAP for PR */
#define CTRL_PCAP_PR_MASK BIT(27)
/* Enable PCAP */
#define CTRL_PCAP_MODE_MASK BIT(26)
/* Lower rate to allow decrypt on the fly */
#define CTRL_PCAP_RATE_EN_MASK BIT(25)
/* System booted in secure mode */
#define CTRL_SEC_EN_MASK BIT(7)
/* Miscellaneous Control Register bit definitions */
/* Internal PCAP loopback */
#define MCTRL_PCAP_LPBK_MASK BIT(4)
/* Status register bit definitions */
/* FPGA init status */
#define STATUS_DMA_Q_F BIT(31)
#define STATUS_DMA_Q_E BIT(30)
#define STATUS_PCFG_INIT_MASK BIT(4)
/* Interrupt Status/Mask Register Bit definitions */
/* DMA command done */
#define IXR_DMA_DONE_MASK BIT(13)
/* DMA and PCAP cmd done */
#define IXR_D_P_DONE_MASK BIT(12)
/* FPGA programmed */
#define IXR_PCFG_DONE_MASK BIT(2)
#define IXR_ERROR_FLAGS_MASK 0x00F0C860
#define IXR_ALL_MASK 0xF8F7F87F
/* Miscellaneous constant values */
/* Invalid DMA addr */
#define DMA_INVALID_ADDRESS GENMASK(31, 0)
/* Used to unlock the dev */
#define UNLOCK_MASK 0x757bdf0d
/* Timeout for polling reset bits */
#define INIT_POLL_TIMEOUT 2500000
/* Delay for polling reset bits */
#define INIT_POLL_DELAY 20
/* Signal this is the last DMA transfer, wait for the AXI and PCAP before
* interrupting
*/
#define DMA_SRC_LAST_TRANSFER 1
/* Timeout for DMA completion */
#define DMA_TIMEOUT_MS 5000
/* Masks for controlling stuff in SLCR */
/* Disable all Level shifters */
#define LVL_SHFTR_DISABLE_ALL_MASK 0x0
/* Enable Level shifters from PS to PL */
#define LVL_SHFTR_ENABLE_PS_TO_PL 0xa
/* Enable Level shifters from PL to PS */
#define LVL_SHFTR_ENABLE_PL_TO_PS 0xf
/* Enable global resets */
#define FPGA_RST_ALL_MASK 0xf
/* Disable global resets */
#define FPGA_RST_NONE_MASK 0x0
struct zynq_fpga_priv {
int irq;
struct clk *clk;
void __iomem *io_base;
struct regmap *slcr;
spinlock_t dma_lock;
unsigned int dma_elm;
unsigned int dma_nelms;
struct scatterlist *cur_sg;
struct completion dma_done;
};
static inline void zynq_fpga_write(struct zynq_fpga_priv *priv, u32 offset,
u32 val)
{
writel(val, priv->io_base + offset);
}
static inline u32 zynq_fpga_read(const struct zynq_fpga_priv *priv,
u32 offset)
{
return readl(priv->io_base + offset);
}
#define zynq_fpga_poll_timeout(priv, addr, val, cond, sleep_us, timeout_us) \
readl_poll_timeout(priv->io_base + addr, val, cond, sleep_us, \
timeout_us)
/* Cause the specified irq mask bits to generate IRQs */
static inline void zynq_fpga_set_irq(struct zynq_fpga_priv *priv, u32 enable)
{
zynq_fpga_write(priv, INT_MASK_OFFSET, ~enable);
}
/* Must be called with dma_lock held */
static void zynq_step_dma(struct zynq_fpga_priv *priv)
{
u32 addr;
u32 len;
bool first;
first = priv->dma_elm == 0;
while (priv->cur_sg) {
/* Feed the DMA queue until it is full. */
if (zynq_fpga_read(priv, STATUS_OFFSET) & STATUS_DMA_Q_F)
break;
addr = sg_dma_address(priv->cur_sg);
len = sg_dma_len(priv->cur_sg);
if (priv->dma_elm + 1 == priv->dma_nelms) {
/* The last transfer waits for the PCAP to finish too,
* notice this also changes the irq_mask to ignore
* IXR_DMA_DONE_MASK which ensures we do not trigger
* the completion too early.
*/
addr |= DMA_SRC_LAST_TRANSFER;
priv->cur_sg = NULL;
} else {
priv->cur_sg = sg_next(priv->cur_sg);
priv->dma_elm++;
}
zynq_fpga_write(priv, DMA_SRC_ADDR_OFFSET, addr);
zynq_fpga_write(priv, DMA_DST_ADDR_OFFSET, DMA_INVALID_ADDRESS);
zynq_fpga_write(priv, DMA_SRC_LEN_OFFSET, len / 4);
zynq_fpga_write(priv, DMA_DEST_LEN_OFFSET, 0);
}
/* Once the first transfer is queued we can turn on the ISR, future
* calls to zynq_step_dma will happen from the ISR context. The
* dma_lock spinlock guarentees this handover is done coherently, the
* ISR enable is put at the end to avoid another CPU spinning in the
* ISR on this lock.
*/
if (first && priv->cur_sg) {
zynq_fpga_set_irq(priv,
IXR_DMA_DONE_MASK | IXR_ERROR_FLAGS_MASK);
} else if (!priv->cur_sg) {
/* The last transfer changes to DMA & PCAP mode since we do
* not want to continue until everything has been flushed into
* the PCAP.
*/
zynq_fpga_set_irq(priv,
IXR_D_P_DONE_MASK | IXR_ERROR_FLAGS_MASK);
}
}
static irqreturn_t zynq_fpga_isr(int irq, void *data)
{
struct zynq_fpga_priv *priv = data;
u32 intr_status;
/* If anything other than DMA completion is reported stop and hand
* control back to zynq_fpga_ops_write, something went wrong,
* otherwise progress the DMA.
*/
spin_lock(&priv->dma_lock);
intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
if (!(intr_status & IXR_ERROR_FLAGS_MASK) &&
(intr_status & IXR_DMA_DONE_MASK) && priv->cur_sg) {
zynq_fpga_write(priv, INT_STS_OFFSET, IXR_DMA_DONE_MASK);
zynq_step_dma(priv);
spin_unlock(&priv->dma_lock);
return IRQ_HANDLED;
}
spin_unlock(&priv->dma_lock);
zynq_fpga_set_irq(priv, 0);
complete(&priv->dma_done);
return IRQ_HANDLED;
}
/* Sanity check the proposed bitstream. It must start with the sync word in
* the correct byte order, and be dword aligned. The input is a Xilinx .bin
* file with every 32 bit quantity swapped.
*/
static bool zynq_fpga_has_sync(const u8 *buf, size_t count)
{
for (; count >= 4; buf += 4, count -= 4)
if (buf[0] == 0x66 && buf[1] == 0x55 && buf[2] == 0x99 &&
buf[3] == 0xaa)
return true;
return false;
}
static int zynq_fpga_ops_write_init(struct fpga_manager *mgr,
struct fpga_image_info *info,
const char *buf, size_t count)
{
struct zynq_fpga_priv *priv;
u32 ctrl, status;
int err;
priv = mgr->priv;
err = clk_enable(priv->clk);
if (err)
return err;
/* check if bitstream is encrypted & and system's still secure */
if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM) {
ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
if (!(ctrl & CTRL_SEC_EN_MASK)) {
dev_err(&mgr->dev,
"System not secure, can't use crypted bitstreams\n");
err = -EINVAL;
goto out_err;
}
}
/* don't globally reset PL if we're doing partial reconfig */
if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
if (!zynq_fpga_has_sync(buf, count)) {
dev_err(&mgr->dev,
"Invalid bitstream, could not find a sync word. Bitstream must be a byte swapped .bin file\n");
err = -EINVAL;
goto out_err;
}
/* assert AXI interface resets */
regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
FPGA_RST_ALL_MASK);
/* disable all level shifters */
regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
LVL_SHFTR_DISABLE_ALL_MASK);
/* enable level shifters from PS to PL */
regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
LVL_SHFTR_ENABLE_PS_TO_PL);
/* create a rising edge on PCFG_INIT. PCFG_INIT follows
* PCFG_PROG_B, so we need to poll it after setting PCFG_PROG_B
* to make sure the rising edge actually happens.
* Note: PCFG_PROG_B is low active, sequence as described in
* UG585 v1.10 page 211
*/
ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
ctrl |= CTRL_PCFG_PROG_B_MASK;
zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
status & STATUS_PCFG_INIT_MASK,
INIT_POLL_DELAY,
INIT_POLL_TIMEOUT);
if (err) {
dev_err(&mgr->dev, "Timeout waiting for PCFG_INIT\n");
goto out_err;
}
ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
ctrl &= ~CTRL_PCFG_PROG_B_MASK;
zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
!(status & STATUS_PCFG_INIT_MASK),
INIT_POLL_DELAY,
INIT_POLL_TIMEOUT);
if (err) {
dev_err(&mgr->dev, "Timeout waiting for !PCFG_INIT\n");
goto out_err;
}
ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
ctrl |= CTRL_PCFG_PROG_B_MASK;
zynq_fpga_write(priv, CTRL_OFFSET, ctrl);
err = zynq_fpga_poll_timeout(priv, STATUS_OFFSET, status,
status & STATUS_PCFG_INIT_MASK,
INIT_POLL_DELAY,
INIT_POLL_TIMEOUT);
if (err) {
dev_err(&mgr->dev, "Timeout waiting for PCFG_INIT\n");
goto out_err;
}
}
/* set configuration register with following options:
* - enable PCAP interface
* - set throughput for maximum speed (if bistream not crypted)
* - set CPU in user mode
*/
ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM)
zynq_fpga_write(priv, CTRL_OFFSET,
(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
| CTRL_PCAP_RATE_EN_MASK | ctrl));
else
zynq_fpga_write(priv, CTRL_OFFSET,
(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
| ctrl));
/* We expect that the command queue is empty right now. */
status = zynq_fpga_read(priv, STATUS_OFFSET);
if ((status & STATUS_DMA_Q_F) ||
(status & STATUS_DMA_Q_E) != STATUS_DMA_Q_E) {
dev_err(&mgr->dev, "DMA command queue not right\n");
err = -EBUSY;
goto out_err;
}
/* ensure internal PCAP loopback is disabled */
ctrl = zynq_fpga_read(priv, MCTRL_OFFSET);
zynq_fpga_write(priv, MCTRL_OFFSET, (~MCTRL_PCAP_LPBK_MASK & ctrl));
clk_disable(priv->clk);
return 0;
out_err:
clk_disable(priv->clk);
return err;
}
static int zynq_fpga_ops_write(struct fpga_manager *mgr, struct sg_table *sgt)
{
struct zynq_fpga_priv *priv;
const char *why;
int err;
u32 intr_status;
unsigned long timeout;
unsigned long flags;
struct scatterlist *sg;
int i;
priv = mgr->priv;
/* The hardware can only DMA multiples of 4 bytes, and it requires the
* starting addresses to be aligned to 64 bits (UG585 pg 212).
*/
for_each_sg(sgt->sgl, sg, sgt->nents, i) {
if ((sg->offset % 8) || (sg->length % 4)) {
dev_err(&mgr->dev,
"Invalid bitstream, chunks must be aligned\n");
return -EINVAL;
}
}
priv->dma_nelms =
dma_map_sg(mgr->dev.parent, sgt->sgl, sgt->nents, DMA_TO_DEVICE);
if (priv->dma_nelms == 0) {
dev_err(&mgr->dev, "Unable to DMA map (TO_DEVICE)\n");
return -ENOMEM;
}
/* enable clock */
err = clk_enable(priv->clk);
if (err)
goto out_free;
zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
reinit_completion(&priv->dma_done);
/* zynq_step_dma will turn on interrupts */
spin_lock_irqsave(&priv->dma_lock, flags);
priv->dma_elm = 0;
priv->cur_sg = sgt->sgl;
zynq_step_dma(priv);
spin_unlock_irqrestore(&priv->dma_lock, flags);
timeout = wait_for_completion_timeout(&priv->dma_done,
msecs_to_jiffies(DMA_TIMEOUT_MS));
spin_lock_irqsave(&priv->dma_lock, flags);
zynq_fpga_set_irq(priv, 0);
priv->cur_sg = NULL;
spin_unlock_irqrestore(&priv->dma_lock, flags);
intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
/* There doesn't seem to be a way to force cancel any DMA, so if
* something went wrong we are relying on the hardware to have halted
* the DMA before we get here, if there was we could use
* wait_for_completion_interruptible too.
*/
if (intr_status & IXR_ERROR_FLAGS_MASK) {
why = "DMA reported error";
err = -EIO;
goto out_report;
}
if (priv->cur_sg ||
!((intr_status & IXR_D_P_DONE_MASK) == IXR_D_P_DONE_MASK)) {
if (timeout == 0)
why = "DMA timed out";
else
why = "DMA did not complete";
err = -EIO;
goto out_report;
}
err = 0;
goto out_clk;
out_report:
dev_err(&mgr->dev,
"%s: INT_STS:0x%x CTRL:0x%x LOCK:0x%x INT_MASK:0x%x STATUS:0x%x MCTRL:0x%x\n",
why,
intr_status,
zynq_fpga_read(priv, CTRL_OFFSET),
zynq_fpga_read(priv, LOCK_OFFSET),
zynq_fpga_read(priv, INT_MASK_OFFSET),
zynq_fpga_read(priv, STATUS_OFFSET),
zynq_fpga_read(priv, MCTRL_OFFSET));
out_clk:
clk_disable(priv->clk);
out_free:
dma_unmap_sg(mgr->dev.parent, sgt->sgl, sgt->nents, DMA_TO_DEVICE);
return err;
}
static int zynq_fpga_ops_write_complete(struct fpga_manager *mgr,
struct fpga_image_info *info)
{
struct zynq_fpga_priv *priv = mgr->priv;
int err;
u32 intr_status;
err = clk_enable(priv->clk);
if (err)
return err;
err = zynq_fpga_poll_timeout(priv, INT_STS_OFFSET, intr_status,
intr_status & IXR_PCFG_DONE_MASK,
INIT_POLL_DELAY,
INIT_POLL_TIMEOUT);
clk_disable(priv->clk);
if (err)
return err;
/* for the partial reconfig case we didn't touch the level shifters */
if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
/* enable level shifters from PL to PS */
regmap_write(priv->slcr, SLCR_LVL_SHFTR_EN_OFFSET,
LVL_SHFTR_ENABLE_PL_TO_PS);
/* deassert AXI interface resets */
regmap_write(priv->slcr, SLCR_FPGA_RST_CTRL_OFFSET,
FPGA_RST_NONE_MASK);
}
return 0;
}
static enum fpga_mgr_states zynq_fpga_ops_state(struct fpga_manager *mgr)
{
int err;
u32 intr_status;
struct zynq_fpga_priv *priv;
priv = mgr->priv;
err = clk_enable(priv->clk);
if (err)
return FPGA_MGR_STATE_UNKNOWN;
intr_status = zynq_fpga_read(priv, INT_STS_OFFSET);
clk_disable(priv->clk);
if (intr_status & IXR_PCFG_DONE_MASK)
return FPGA_MGR_STATE_OPERATING;
return FPGA_MGR_STATE_UNKNOWN;
}
static const struct fpga_manager_ops zynq_fpga_ops = {
.initial_header_size = 128,
.state = zynq_fpga_ops_state,
.write_init = zynq_fpga_ops_write_init,
.write_sg = zynq_fpga_ops_write,
.write_complete = zynq_fpga_ops_write_complete,
};
static int zynq_fpga_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct zynq_fpga_priv *priv;
struct resource *res;
int err;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
spin_lock_init(&priv->dma_lock);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->io_base = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->io_base))
return PTR_ERR(priv->io_base);
priv->slcr = syscon_regmap_lookup_by_phandle(dev->of_node,
"syscon");
if (IS_ERR(priv->slcr)) {
dev_err(dev, "unable to get zynq-slcr regmap\n");
return PTR_ERR(priv->slcr);
}
init_completion(&priv->dma_done);
priv->irq = platform_get_irq(pdev, 0);
if (priv->irq < 0) {
dev_err(dev, "No IRQ available\n");
return priv->irq;
}
priv->clk = devm_clk_get(dev, "ref_clk");
if (IS_ERR(priv->clk)) {
dev_err(dev, "input clock not found\n");
return PTR_ERR(priv->clk);
}
err = clk_prepare_enable(priv->clk);
if (err) {
dev_err(dev, "unable to enable clock\n");
return err;
}
/* unlock the device */
zynq_fpga_write(priv, UNLOCK_OFFSET, UNLOCK_MASK);
zynq_fpga_set_irq(priv, 0);
zynq_fpga_write(priv, INT_STS_OFFSET, IXR_ALL_MASK);
err = devm_request_irq(dev, priv->irq, zynq_fpga_isr, 0, dev_name(dev),
priv);
if (err) {
dev_err(dev, "unable to request IRQ\n");
clk_disable_unprepare(priv->clk);
return err;
}
clk_disable(priv->clk);
err = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
&zynq_fpga_ops, priv);
if (err) {
dev_err(dev, "unable to register FPGA manager\n");
clk_unprepare(priv->clk);
return err;
}
return 0;
}
static int zynq_fpga_remove(struct platform_device *pdev)
{
struct zynq_fpga_priv *priv;
struct fpga_manager *mgr;
mgr = platform_get_drvdata(pdev);
priv = mgr->priv;
fpga_mgr_unregister(&pdev->dev);
clk_unprepare(priv->clk);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id zynq_fpga_of_match[] = {
{ .compatible = "xlnx,zynq-devcfg-1.0", },
{},
};
MODULE_DEVICE_TABLE(of, zynq_fpga_of_match);
#endif
static struct platform_driver zynq_fpga_driver = {
.probe = zynq_fpga_probe,
.remove = zynq_fpga_remove,
.driver = {
.name = "zynq_fpga_manager",
.of_match_table = of_match_ptr(zynq_fpga_of_match),
},
};
module_platform_driver(zynq_fpga_driver);
MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>");
MODULE_DESCRIPTION("Xilinx Zynq FPGA Manager");
MODULE_LICENSE("GPL v2");
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