linux/drivers/fpga/altera-pr-ip-core.c
Marco Pagani 2df84a757d
fpga: altera-pr-ip: fix unsigned comparison with less than zero
Fix the "comparison with less than zero" warning reported by
cppcheck for the unsigned (size_t) parameter count of the
alt_pr_fpga_write() function.

Fixes: d201cc17a8 ("fpga pr ip: Core driver support for Altera Partial Reconfiguration IP")
Reviewed-by: Tom Rix <trix@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Marco Pagani <marpagan@redhat.com>
Link: https://lore.kernel.org/r/20220609140520.42662-1-marpagan@redhat.com
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
2022-06-10 15:48:23 +08:00

202 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Driver for Altera Partial Reconfiguration IP Core
*
* Copyright (C) 2016-2017 Intel Corporation
*
* Based on socfpga-a10.c Copyright (C) 2015-2016 Altera Corporation
* by Alan Tull <atull@opensource.altera.com>
*/
#include <linux/delay.h>
#include <linux/fpga/altera-pr-ip-core.h>
#include <linux/fpga/fpga-mgr.h>
#include <linux/module.h>
#define ALT_PR_DATA_OFST 0x00
#define ALT_PR_CSR_OFST 0x04
#define ALT_PR_CSR_PR_START BIT(0)
#define ALT_PR_CSR_STATUS_SFT 2
#define ALT_PR_CSR_STATUS_MSK (7 << ALT_PR_CSR_STATUS_SFT)
#define ALT_PR_CSR_STATUS_NRESET (0 << ALT_PR_CSR_STATUS_SFT)
#define ALT_PR_CSR_STATUS_PR_ERR (1 << ALT_PR_CSR_STATUS_SFT)
#define ALT_PR_CSR_STATUS_CRC_ERR (2 << ALT_PR_CSR_STATUS_SFT)
#define ALT_PR_CSR_STATUS_BAD_BITS (3 << ALT_PR_CSR_STATUS_SFT)
#define ALT_PR_CSR_STATUS_PR_IN_PROG (4 << ALT_PR_CSR_STATUS_SFT)
#define ALT_PR_CSR_STATUS_PR_SUCCESS (5 << ALT_PR_CSR_STATUS_SFT)
struct alt_pr_priv {
void __iomem *reg_base;
};
static enum fpga_mgr_states alt_pr_fpga_state(struct fpga_manager *mgr)
{
struct alt_pr_priv *priv = mgr->priv;
const char *err = "unknown";
enum fpga_mgr_states ret = FPGA_MGR_STATE_UNKNOWN;
u32 val;
val = readl(priv->reg_base + ALT_PR_CSR_OFST);
val &= ALT_PR_CSR_STATUS_MSK;
switch (val) {
case ALT_PR_CSR_STATUS_NRESET:
return FPGA_MGR_STATE_RESET;
case ALT_PR_CSR_STATUS_PR_ERR:
err = "pr error";
ret = FPGA_MGR_STATE_WRITE_ERR;
break;
case ALT_PR_CSR_STATUS_CRC_ERR:
err = "crc error";
ret = FPGA_MGR_STATE_WRITE_ERR;
break;
case ALT_PR_CSR_STATUS_BAD_BITS:
err = "bad bits";
ret = FPGA_MGR_STATE_WRITE_ERR;
break;
case ALT_PR_CSR_STATUS_PR_IN_PROG:
return FPGA_MGR_STATE_WRITE;
case ALT_PR_CSR_STATUS_PR_SUCCESS:
return FPGA_MGR_STATE_OPERATING;
default:
break;
}
dev_err(&mgr->dev, "encountered error code %d (%s) in %s()\n",
val, err, __func__);
return ret;
}
static int alt_pr_fpga_write_init(struct fpga_manager *mgr,
struct fpga_image_info *info,
const char *buf, size_t count)
{
struct alt_pr_priv *priv = mgr->priv;
u32 val;
if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
dev_err(&mgr->dev, "%s Partial Reconfiguration flag not set\n",
__func__);
return -EINVAL;
}
val = readl(priv->reg_base + ALT_PR_CSR_OFST);
if (val & ALT_PR_CSR_PR_START) {
dev_err(&mgr->dev,
"%s Partial Reconfiguration already started\n",
__func__);
return -EINVAL;
}
writel(val | ALT_PR_CSR_PR_START, priv->reg_base + ALT_PR_CSR_OFST);
return 0;
}
static int alt_pr_fpga_write(struct fpga_manager *mgr, const char *buf,
size_t count)
{
struct alt_pr_priv *priv = mgr->priv;
u32 *buffer_32 = (u32 *)buf;
size_t i = 0;
if (!count)
return -EINVAL;
/* Write out the complete 32-bit chunks */
while (count >= sizeof(u32)) {
writel(buffer_32[i++], priv->reg_base);
count -= sizeof(u32);
}
/* Write out remaining non 32-bit chunks */
switch (count) {
case 3:
writel(buffer_32[i++] & 0x00ffffff, priv->reg_base);
break;
case 2:
writel(buffer_32[i++] & 0x0000ffff, priv->reg_base);
break;
case 1:
writel(buffer_32[i++] & 0x000000ff, priv->reg_base);
break;
case 0:
break;
default:
/* This will never happen */
return -EFAULT;
}
if (alt_pr_fpga_state(mgr) == FPGA_MGR_STATE_WRITE_ERR)
return -EIO;
return 0;
}
static int alt_pr_fpga_write_complete(struct fpga_manager *mgr,
struct fpga_image_info *info)
{
u32 i = 0;
do {
switch (alt_pr_fpga_state(mgr)) {
case FPGA_MGR_STATE_WRITE_ERR:
return -EIO;
case FPGA_MGR_STATE_OPERATING:
dev_info(&mgr->dev,
"successful partial reconfiguration\n");
return 0;
default:
break;
}
udelay(1);
} while (info->config_complete_timeout_us > i++);
dev_err(&mgr->dev, "timed out waiting for write to complete\n");
return -ETIMEDOUT;
}
static const struct fpga_manager_ops alt_pr_ops = {
.state = alt_pr_fpga_state,
.write_init = alt_pr_fpga_write_init,
.write = alt_pr_fpga_write,
.write_complete = alt_pr_fpga_write_complete,
};
int alt_pr_register(struct device *dev, void __iomem *reg_base)
{
struct alt_pr_priv *priv;
struct fpga_manager *mgr;
u32 val;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->reg_base = reg_base;
val = readl(priv->reg_base + ALT_PR_CSR_OFST);
dev_dbg(dev, "%s status=%d start=%d\n", __func__,
(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
(int)(val & ALT_PR_CSR_PR_START));
mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
return PTR_ERR_OR_ZERO(mgr);
}
EXPORT_SYMBOL_GPL(alt_pr_register);
MODULE_AUTHOR("Matthew Gerlach <matthew.gerlach@linux.intel.com>");
MODULE_DESCRIPTION("Altera Partial Reconfiguration IP Core");
MODULE_LICENSE("GPL v2");