linux/drivers/spi/spi-sprd-adi.c
Baolin Wang 54e2fc28d9 spi: sprd: Fix the possible negative value of BIT()
When enabling the ADI hardware channels, if the channel id is 31,
then we will get one negative value -1 for BIT() macro, which will
write incorrect value to register.

Fixes: 7e2903cb91 ("spi: Add ADI driver for Spreadtrum platform")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-10-25 14:00:03 +02:00

419 lines
10 KiB
C

/*
* Copyright (C) 2017 Spreadtrum Communications Inc.
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <linux/hwspinlock.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/sizes.h>
/* Registers definitions for ADI controller */
#define REG_ADI_CTRL0 0x4
#define REG_ADI_CHN_PRIL 0x8
#define REG_ADI_CHN_PRIH 0xc
#define REG_ADI_INT_EN 0x10
#define REG_ADI_INT_RAW 0x14
#define REG_ADI_INT_MASK 0x18
#define REG_ADI_INT_CLR 0x1c
#define REG_ADI_GSSI_CFG0 0x20
#define REG_ADI_GSSI_CFG1 0x24
#define REG_ADI_RD_CMD 0x28
#define REG_ADI_RD_DATA 0x2c
#define REG_ADI_ARM_FIFO_STS 0x30
#define REG_ADI_STS 0x34
#define REG_ADI_EVT_FIFO_STS 0x38
#define REG_ADI_ARM_CMD_STS 0x3c
#define REG_ADI_CHN_EN 0x40
#define REG_ADI_CHN_ADDR(id) (0x44 + (id - 2) * 4)
#define REG_ADI_CHN_EN1 0x20c
/* Bits definitions for register REG_ADI_GSSI_CFG0 */
#define BIT_CLK_ALL_ON BIT(30)
/* Bits definitions for register REG_ADI_RD_DATA */
#define BIT_RD_CMD_BUSY BIT(31)
#define RD_ADDR_SHIFT 16
#define RD_VALUE_MASK GENMASK(15, 0)
#define RD_ADDR_MASK GENMASK(30, 16)
/* Bits definitions for register REG_ADI_ARM_FIFO_STS */
#define BIT_FIFO_FULL BIT(11)
#define BIT_FIFO_EMPTY BIT(10)
/*
* ADI slave devices include RTC, ADC, regulator, charger, thermal and so on.
* The slave devices address offset is always 0x8000 and size is 4K.
*/
#define ADI_SLAVE_ADDR_SIZE SZ_4K
#define ADI_SLAVE_OFFSET 0x8000
/* Timeout (ms) for the trylock of hardware spinlocks */
#define ADI_HWSPINLOCK_TIMEOUT 5000
/*
* ADI controller has 50 channels including 2 software channels
* and 48 hardware channels.
*/
#define ADI_HW_CHNS 50
#define ADI_FIFO_DRAIN_TIMEOUT 1000
#define ADI_READ_TIMEOUT 2000
#define REG_ADDR_LOW_MASK GENMASK(11, 0)
struct sprd_adi {
struct spi_controller *ctlr;
struct device *dev;
void __iomem *base;
struct hwspinlock *hwlock;
unsigned long slave_vbase;
unsigned long slave_pbase;
};
static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
{
if (paddr < sadi->slave_pbase || paddr >
(sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
dev_err(sadi->dev,
"slave physical address is incorrect, addr = 0x%x\n",
paddr);
return -EINVAL;
}
return 0;
}
static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
{
return (paddr - sadi->slave_pbase + sadi->slave_vbase);
}
static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
{
u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
u32 sts;
do {
sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
if (sts & BIT_FIFO_EMPTY)
break;
cpu_relax();
} while (--timeout);
if (timeout == 0) {
dev_err(sadi->dev, "drain write fifo timeout\n");
return -EBUSY;
}
return 0;
}
static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
{
return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
}
static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
{
int read_timeout = ADI_READ_TIMEOUT;
u32 val, rd_addr;
/*
* Set the physical register address need to read into RD_CMD register,
* then ADI controller will start to transfer automatically.
*/
writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);
/*
* Wait read operation complete, the BIT_RD_CMD_BUSY will be set
* simultaneously when writing read command to register, and the
* BIT_RD_CMD_BUSY will be cleared after the read operation is
* completed.
*/
do {
val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
if (!(val & BIT_RD_CMD_BUSY))
break;
cpu_relax();
} while (--read_timeout);
if (read_timeout == 0) {
dev_err(sadi->dev, "ADI read timeout\n");
return -EBUSY;
}
/*
* The return value includes data and read register address, from bit 0
* to bit 15 are data, and from bit 16 to bit 30 are read register
* address. Then we can check the returned register address to validate
* data.
*/
rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;
if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
reg_paddr, val);
return -EIO;
}
*read_val = val & RD_VALUE_MASK;
return 0;
}
static int sprd_adi_write(struct sprd_adi *sadi, unsigned long reg, u32 val)
{
u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
int ret;
ret = sprd_adi_drain_fifo(sadi);
if (ret < 0)
return ret;
/*
* we should wait for write fifo is empty before writing data to PMIC
* registers.
*/
do {
if (!sprd_adi_fifo_is_full(sadi)) {
writel_relaxed(val, (void __iomem *)reg);
break;
}
cpu_relax();
} while (--timeout);
if (timeout == 0) {
dev_err(sadi->dev, "write fifo is full\n");
return -EBUSY;
}
return 0;
}
static int sprd_adi_transfer_one(struct spi_controller *ctlr,
struct spi_device *spi_dev,
struct spi_transfer *t)
{
struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
unsigned long flags, virt_reg;
u32 phy_reg, val;
int ret;
if (t->rx_buf) {
phy_reg = *(u32 *)t->rx_buf + sadi->slave_pbase;
ret = sprd_adi_check_paddr(sadi, phy_reg);
if (ret)
return ret;
ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
ADI_HWSPINLOCK_TIMEOUT,
&flags);
if (ret) {
dev_err(sadi->dev, "get the hw lock failed\n");
return ret;
}
ret = sprd_adi_read(sadi, phy_reg, &val);
hwspin_unlock_irqrestore(sadi->hwlock, &flags);
if (ret)
return ret;
*(u32 *)t->rx_buf = val;
} else if (t->tx_buf) {
u32 *p = (u32 *)t->tx_buf;
/*
* Get the physical register address need to write and convert
* the physical address to virtual address. Since we need
* virtual register address to write.
*/
phy_reg = *p++ + sadi->slave_pbase;
ret = sprd_adi_check_paddr(sadi, phy_reg);
if (ret)
return ret;
virt_reg = sprd_adi_to_vaddr(sadi, phy_reg);
val = *p;
ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
ADI_HWSPINLOCK_TIMEOUT,
&flags);
if (ret) {
dev_err(sadi->dev, "get the hw lock failed\n");
return ret;
}
ret = sprd_adi_write(sadi, virt_reg, val);
hwspin_unlock_irqrestore(sadi->hwlock, &flags);
if (ret)
return ret;
} else {
dev_err(sadi->dev, "no buffer for transfer\n");
return -EINVAL;
}
return 0;
}
static void sprd_adi_hw_init(struct sprd_adi *sadi)
{
struct device_node *np = sadi->dev->of_node;
int i, size, chn_cnt;
const __be32 *list;
u32 tmp;
/* Address bits select default 12 bits */
writel_relaxed(0, sadi->base + REG_ADI_CTRL0);
/* Set all channels as default priority */
writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);
/* Set clock auto gate mode */
tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
tmp &= ~BIT_CLK_ALL_ON;
writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);
/* Set hardware channels setting */
list = of_get_property(np, "sprd,hw-channels", &size);
if (!list || !size) {
dev_info(sadi->dev, "no hw channels setting in node\n");
return;
}
chn_cnt = size / 8;
for (i = 0; i < chn_cnt; i++) {
u32 value;
u32 chn_id = be32_to_cpu(*list++);
u32 chn_config = be32_to_cpu(*list++);
/* Channel 0 and 1 are software channels */
if (chn_id < 2)
continue;
writel_relaxed(chn_config, sadi->base +
REG_ADI_CHN_ADDR(chn_id));
if (chn_id < 32) {
value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
value |= BIT(chn_id);
writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
} else if (chn_id < ADI_HW_CHNS) {
value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
value |= BIT(chn_id - 32);
writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
}
}
}
static int sprd_adi_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct spi_controller *ctlr;
struct sprd_adi *sadi;
struct resource *res;
u32 num_chipselect;
int ret;
if (!np) {
dev_err(&pdev->dev, "can not find the adi bus node\n");
return -ENODEV;
}
pdev->id = of_alias_get_id(np, "spi");
num_chipselect = of_get_child_count(np);
ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
if (!ctlr)
return -ENOMEM;
dev_set_drvdata(&pdev->dev, ctlr);
sadi = spi_controller_get_devdata(ctlr);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sadi->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(sadi->base)) {
ret = PTR_ERR(sadi->base);
goto put_ctlr;
}
sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
sadi->ctlr = ctlr;
sadi->dev = &pdev->dev;
ret = of_hwspin_lock_get_id(np, 0);
if (ret < 0) {
dev_err(&pdev->dev, "can not get the hardware spinlock\n");
goto put_ctlr;
}
sadi->hwlock = hwspin_lock_request_specific(ret);
if (!sadi->hwlock) {
ret = -ENXIO;
goto put_ctlr;
}
sprd_adi_hw_init(sadi);
ctlr->dev.of_node = pdev->dev.of_node;
ctlr->bus_num = pdev->id;
ctlr->num_chipselect = num_chipselect;
ctlr->flags = SPI_MASTER_HALF_DUPLEX;
ctlr->bits_per_word_mask = 0;
ctlr->transfer_one = sprd_adi_transfer_one;
ret = devm_spi_register_controller(&pdev->dev, ctlr);
if (ret) {
dev_err(&pdev->dev, "failed to register SPI controller\n");
goto free_hwlock;
}
return 0;
free_hwlock:
hwspin_lock_free(sadi->hwlock);
put_ctlr:
spi_controller_put(ctlr);
return ret;
}
static int sprd_adi_remove(struct platform_device *pdev)
{
struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
hwspin_lock_free(sadi->hwlock);
return 0;
}
static const struct of_device_id sprd_adi_of_match[] = {
{
.compatible = "sprd,sc9860-adi",
},
{ },
};
MODULE_DEVICE_TABLE(of, sprd_adi_of_match);
static struct platform_driver sprd_adi_driver = {
.driver = {
.name = "sprd-adi",
.of_match_table = sprd_adi_of_match,
},
.probe = sprd_adi_probe,
.remove = sprd_adi_remove,
};
module_platform_driver(sprd_adi_driver);
MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
MODULE_LICENSE("GPL v2");