linux/drivers/bus/hisi_lpc.c
Uwe Kleine-König ce0ca86582 bus: hisi_lpc: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Link: https://lore.kernel.org/r/20231109202830.4124591-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2023-11-28 18:43:26 +01:00

695 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Hisilicon Limited, All Rights Reserved.
* Author: Zhichang Yuan <yuanzhichang@hisilicon.com>
* Author: Zou Rongrong <zourongrong@huawei.com>
* Author: John Garry <john.garry@huawei.com>
*/
#include <linux/acpi.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/logic_pio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/serial_8250.h>
#include <linux/slab.h>
#define DRV_NAME "hisi-lpc"
/*
* Setting this bit means each IO operation will target a different port
* address; 0 means repeated IO operations will use the same port,
* such as BT.
*/
#define FG_INCRADDR_LPC 0x02
struct lpc_cycle_para {
unsigned int opflags;
unsigned int csize; /* data length of each operation */
};
struct hisi_lpc_dev {
spinlock_t cycle_lock;
void __iomem *membase;
struct logic_pio_hwaddr *io_host;
};
/* The max IO cycle counts supported is four per operation at maximum */
#define LPC_MAX_DWIDTH 4
#define LPC_REG_STARTUP_SIGNAL 0x00
#define LPC_REG_STARTUP_SIGNAL_START BIT(0)
#define LPC_REG_OP_STATUS 0x04
#define LPC_REG_OP_STATUS_IDLE BIT(0)
#define LPC_REG_OP_STATUS_FINISHED BIT(1)
#define LPC_REG_OP_LEN 0x10 /* LPC cycles count per start */
#define LPC_REG_CMD 0x14
#define LPC_REG_CMD_OP BIT(0) /* 0: read, 1: write */
#define LPC_REG_CMD_SAMEADDR BIT(3)
#define LPC_REG_ADDR 0x20 /* target address */
#define LPC_REG_WDATA 0x24 /* write FIFO */
#define LPC_REG_RDATA 0x28 /* read FIFO */
/* The minimal nanosecond interval for each query on LPC cycle status */
#define LPC_NSEC_PERWAIT 100
/*
* The maximum waiting time is about 128us. It is specific for stream I/O,
* such as ins.
*
* The fastest IO cycle time is about 390ns, but the worst case will wait
* for extra 256 lpc clocks, so (256 + 13) * 30ns = 8 us. The maximum burst
* cycles is 16. So, the maximum waiting time is about 128us under worst
* case.
*
* Choose 1300 as the maximum.
*/
#define LPC_MAX_WAITCNT 1300
/* About 10us. This is specific for single IO operations, such as inb */
#define LPC_PEROP_WAITCNT 100
static int wait_lpc_idle(void __iomem *mbase, unsigned int waitcnt)
{
u32 status;
do {
status = readl(mbase + LPC_REG_OP_STATUS);
if (status & LPC_REG_OP_STATUS_IDLE)
return (status & LPC_REG_OP_STATUS_FINISHED) ? 0 : -EIO;
ndelay(LPC_NSEC_PERWAIT);
} while (--waitcnt);
return -ETIMEDOUT;
}
/*
* hisi_lpc_target_in - trigger a series of LPC cycles for read operation
* @lpcdev: pointer to hisi lpc device
* @para: some parameters used to control the lpc I/O operations
* @addr: the lpc I/O target port address
* @buf: where the read back data is stored
* @opcnt: how many I/O operations required, i.e. data width
*
* Returns 0 on success, non-zero on fail.
*/
static int hisi_lpc_target_in(struct hisi_lpc_dev *lpcdev,
struct lpc_cycle_para *para, unsigned long addr,
unsigned char *buf, unsigned long opcnt)
{
unsigned int cmd_word;
unsigned int waitcnt;
unsigned long flags;
int ret;
if (!buf || !opcnt || !para || !para->csize || !lpcdev)
return -EINVAL;
cmd_word = 0; /* IO mode, Read */
waitcnt = LPC_PEROP_WAITCNT;
if (!(para->opflags & FG_INCRADDR_LPC)) {
cmd_word |= LPC_REG_CMD_SAMEADDR;
waitcnt = LPC_MAX_WAITCNT;
}
/* whole operation must be atomic */
spin_lock_irqsave(&lpcdev->cycle_lock, flags);
writel_relaxed(opcnt, lpcdev->membase + LPC_REG_OP_LEN);
writel_relaxed(cmd_word, lpcdev->membase + LPC_REG_CMD);
writel_relaxed(addr, lpcdev->membase + LPC_REG_ADDR);
writel(LPC_REG_STARTUP_SIGNAL_START,
lpcdev->membase + LPC_REG_STARTUP_SIGNAL);
/* whether the operation is finished */
ret = wait_lpc_idle(lpcdev->membase, waitcnt);
if (ret) {
spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
return ret;
}
readsb(lpcdev->membase + LPC_REG_RDATA, buf, opcnt);
spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
return 0;
}
/*
* hisi_lpc_target_out - trigger a series of LPC cycles for write operation
* @lpcdev: pointer to hisi lpc device
* @para: some parameters used to control the lpc I/O operations
* @addr: the lpc I/O target port address
* @buf: where the data to be written is stored
* @opcnt: how many I/O operations required, i.e. data width
*
* Returns 0 on success, non-zero on fail.
*/
static int hisi_lpc_target_out(struct hisi_lpc_dev *lpcdev,
struct lpc_cycle_para *para, unsigned long addr,
const unsigned char *buf, unsigned long opcnt)
{
unsigned int waitcnt;
unsigned long flags;
u32 cmd_word;
int ret;
if (!buf || !opcnt || !para || !lpcdev)
return -EINVAL;
/* default is increasing address */
cmd_word = LPC_REG_CMD_OP; /* IO mode, write */
waitcnt = LPC_PEROP_WAITCNT;
if (!(para->opflags & FG_INCRADDR_LPC)) {
cmd_word |= LPC_REG_CMD_SAMEADDR;
waitcnt = LPC_MAX_WAITCNT;
}
spin_lock_irqsave(&lpcdev->cycle_lock, flags);
writel_relaxed(opcnt, lpcdev->membase + LPC_REG_OP_LEN);
writel_relaxed(cmd_word, lpcdev->membase + LPC_REG_CMD);
writel_relaxed(addr, lpcdev->membase + LPC_REG_ADDR);
writesb(lpcdev->membase + LPC_REG_WDATA, buf, opcnt);
writel(LPC_REG_STARTUP_SIGNAL_START,
lpcdev->membase + LPC_REG_STARTUP_SIGNAL);
/* whether the operation is finished */
ret = wait_lpc_idle(lpcdev->membase, waitcnt);
spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
return ret;
}
static unsigned long hisi_lpc_pio_to_addr(struct hisi_lpc_dev *lpcdev,
unsigned long pio)
{
return pio - lpcdev->io_host->io_start + lpcdev->io_host->hw_start;
}
/*
* hisi_lpc_comm_in - input the data in a single operation
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @dwidth: the data length required to read from the target I/O port
*
* When success, data is returned. Otherwise, ~0 is returned.
*/
static u32 hisi_lpc_comm_in(void *hostdata, unsigned long pio, size_t dwidth)
{
struct hisi_lpc_dev *lpcdev = hostdata;
struct lpc_cycle_para iopara;
unsigned long addr;
__le32 rd_data = 0;
int ret;
if (!lpcdev || !dwidth || dwidth > LPC_MAX_DWIDTH)
return ~0;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
iopara.opflags = FG_INCRADDR_LPC;
iopara.csize = dwidth;
ret = hisi_lpc_target_in(lpcdev, &iopara, addr,
(unsigned char *)&rd_data, dwidth);
if (ret)
return ~0;
return le32_to_cpu(rd_data);
}
/*
* hisi_lpc_comm_out - output the data in a single operation
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @val: a value to be output from caller, maximum is four bytes
* @dwidth: the data width required writing to the target I/O port
*
* This function corresponds to out(b,w,l) only.
*/
static void hisi_lpc_comm_out(void *hostdata, unsigned long pio,
u32 val, size_t dwidth)
{
struct hisi_lpc_dev *lpcdev = hostdata;
struct lpc_cycle_para iopara;
const unsigned char *buf;
unsigned long addr;
__le32 _val = cpu_to_le32(val);
if (!lpcdev || !dwidth || dwidth > LPC_MAX_DWIDTH)
return;
buf = (const unsigned char *)&_val;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
iopara.opflags = FG_INCRADDR_LPC;
iopara.csize = dwidth;
hisi_lpc_target_out(lpcdev, &iopara, addr, buf, dwidth);
}
/*
* hisi_lpc_comm_ins - input the data in the buffer in multiple operations
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @buffer: a buffer where read/input data bytes are stored
* @dwidth: the data width required writing to the target I/O port
* @count: how many data units whose length is dwidth will be read
*
* When success, the data read back is stored in buffer pointed by buffer.
* Returns 0 on success, -errno otherwise.
*/
static u32 hisi_lpc_comm_ins(void *hostdata, unsigned long pio, void *buffer,
size_t dwidth, unsigned int count)
{
struct hisi_lpc_dev *lpcdev = hostdata;
unsigned char *buf = buffer;
struct lpc_cycle_para iopara;
unsigned long addr;
if (!lpcdev || !buf || !count || !dwidth || dwidth > LPC_MAX_DWIDTH)
return -EINVAL;
iopara.opflags = 0;
if (dwidth > 1)
iopara.opflags |= FG_INCRADDR_LPC;
iopara.csize = dwidth;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
do {
int ret;
ret = hisi_lpc_target_in(lpcdev, &iopara, addr, buf, dwidth);
if (ret)
return ret;
buf += dwidth;
} while (--count);
return 0;
}
/*
* hisi_lpc_comm_outs - output the data in the buffer in multiple operations
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @buffer: a buffer where write/output data bytes are stored
* @dwidth: the data width required writing to the target I/O port
* @count: how many data units whose length is dwidth will be written
*/
static void hisi_lpc_comm_outs(void *hostdata, unsigned long pio,
const void *buffer, size_t dwidth,
unsigned int count)
{
struct hisi_lpc_dev *lpcdev = hostdata;
struct lpc_cycle_para iopara;
const unsigned char *buf = buffer;
unsigned long addr;
if (!lpcdev || !buf || !count || !dwidth || dwidth > LPC_MAX_DWIDTH)
return;
iopara.opflags = 0;
if (dwidth > 1)
iopara.opflags |= FG_INCRADDR_LPC;
iopara.csize = dwidth;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
do {
if (hisi_lpc_target_out(lpcdev, &iopara, addr, buf, dwidth))
break;
buf += dwidth;
} while (--count);
}
static const struct logic_pio_host_ops hisi_lpc_ops = {
.in = hisi_lpc_comm_in,
.out = hisi_lpc_comm_out,
.ins = hisi_lpc_comm_ins,
.outs = hisi_lpc_comm_outs,
};
#ifdef CONFIG_ACPI
static int hisi_lpc_acpi_xlat_io_res(struct acpi_device *adev,
struct acpi_device *host,
struct resource *res)
{
unsigned long sys_port;
resource_size_t len = resource_size(res);
sys_port = logic_pio_trans_hwaddr(acpi_fwnode_handle(host), res->start, len);
if (sys_port == ~0UL)
return -EFAULT;
res->start = sys_port;
res->end = sys_port + len;
return 0;
}
/*
* Released firmware describes the IO port max address as 0x3fff, which is
* the max host bus address. Fixup to a proper range. This will probably
* never be fixed in firmware.
*/
static void hisi_lpc_acpi_fixup_child_resource(struct device *hostdev,
struct resource *r)
{
if (r->end != 0x3fff)
return;
if (r->start == 0xe4)
r->end = 0xe4 + 0x04 - 1;
else if (r->start == 0x2f8)
r->end = 0x2f8 + 0x08 - 1;
else
dev_warn(hostdev, "unrecognised resource %pR to fixup, ignoring\n",
r);
}
/*
* hisi_lpc_acpi_set_io_res - set the resources for a child
* @adev: ACPI companion of the device node to be updated the I/O resource
* @hostdev: the device node associated with host controller
* @res: double pointer to be set to the address of translated resources
* @num_res: pointer to variable to hold the number of translated resources
*
* Returns 0 when successful, and a negative value for failure.
*
* For a given host controller, each child device will have an associated
* host-relative address resource. This function will return the translated
* logical PIO addresses for each child devices resources.
*/
static int hisi_lpc_acpi_set_io_res(struct acpi_device *adev,
struct device *hostdev,
const struct resource **res, int *num_res)
{
struct acpi_device *host = to_acpi_device(adev->dev.parent);
struct resource_entry *rentry;
LIST_HEAD(resource_list);
struct resource *resources;
int count;
int i;
if (!adev->status.present) {
dev_dbg(&adev->dev, "device is not present\n");
return -EIO;
}
if (acpi_device_enumerated(adev)) {
dev_dbg(&adev->dev, "has been enumerated\n");
return -EIO;
}
/*
* The following code segment to retrieve the resources is common to
* acpi_create_platform_device(), so consider a common helper function
* in future.
*/
count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
if (count <= 0) {
dev_dbg(&adev->dev, "failed to get resources\n");
return count ? count : -EIO;
}
resources = devm_kcalloc(hostdev, count, sizeof(*resources),
GFP_KERNEL);
if (!resources) {
dev_warn(hostdev, "could not allocate memory for %d resources\n",
count);
acpi_dev_free_resource_list(&resource_list);
return -ENOMEM;
}
count = 0;
list_for_each_entry(rentry, &resource_list, node) {
resources[count] = *rentry->res;
hisi_lpc_acpi_fixup_child_resource(hostdev, &resources[count]);
count++;
}
acpi_dev_free_resource_list(&resource_list);
/* translate the I/O resources */
for (i = 0; i < count; i++) {
int ret;
if (!(resources[i].flags & IORESOURCE_IO))
continue;
ret = hisi_lpc_acpi_xlat_io_res(adev, host, &resources[i]);
if (ret) {
dev_err(&adev->dev, "translate IO range %pR failed (%d)\n",
&resources[i], ret);
return ret;
}
}
*res = resources;
*num_res = count;
return 0;
}
static int hisi_lpc_acpi_remove_subdev(struct device *dev, void *unused)
{
platform_device_unregister(to_platform_device(dev));
return 0;
}
static int hisi_lpc_acpi_clear_enumerated(struct acpi_device *adev, void *not_used)
{
acpi_device_clear_enumerated(adev);
return 0;
}
struct hisi_lpc_acpi_cell {
const char *hid;
const struct platform_device_info *pdevinfo;
};
static void hisi_lpc_acpi_remove(struct device *hostdev)
{
device_for_each_child(hostdev, NULL, hisi_lpc_acpi_remove_subdev);
acpi_dev_for_each_child(ACPI_COMPANION(hostdev),
hisi_lpc_acpi_clear_enumerated, NULL);
}
static int hisi_lpc_acpi_add_child(struct acpi_device *child, void *data)
{
const char *hid = acpi_device_hid(child);
struct device *hostdev = data;
const struct hisi_lpc_acpi_cell *cell;
struct platform_device *pdev;
const struct resource *res;
bool found = false;
int num_res;
int ret;
ret = hisi_lpc_acpi_set_io_res(child, hostdev, &res, &num_res);
if (ret) {
dev_warn(hostdev, "set resource fail (%d)\n", ret);
return ret;
}
cell = (struct hisi_lpc_acpi_cell []){
/* ipmi */
{
.hid = "IPI0001",
.pdevinfo = (struct platform_device_info []) {
{
.parent = hostdev,
.fwnode = acpi_fwnode_handle(child),
.name = "hisi-lpc-ipmi",
.id = PLATFORM_DEVID_AUTO,
.res = res,
.num_res = num_res,
},
},
},
/* 8250-compatible uart */
{
.hid = "HISI1031",
.pdevinfo = (struct platform_device_info []) {
{
.parent = hostdev,
.fwnode = acpi_fwnode_handle(child),
.name = "serial8250",
.id = PLATFORM_DEVID_AUTO,
.res = res,
.num_res = num_res,
.data = (struct plat_serial8250_port []) {
{
.iobase = res->start,
.uartclk = 1843200,
.iotype = UPIO_PORT,
.flags = UPF_BOOT_AUTOCONF,
},
{}
},
.size_data = 2 * sizeof(struct plat_serial8250_port),
},
},
},
{}
};
for (; cell && cell->hid; cell++) {
if (!strcmp(cell->hid, hid)) {
found = true;
break;
}
}
if (!found) {
dev_warn(hostdev,
"could not find cell for child device (%s), discarding\n",
hid);
return 0;
}
pdev = platform_device_register_full(cell->pdevinfo);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
acpi_device_set_enumerated(child);
return 0;
}
/*
* hisi_lpc_acpi_probe - probe children for ACPI FW
* @hostdev: LPC host device pointer
*
* Returns 0 when successful, and a negative value for failure.
*
* Create a platform device per child, fixing up the resources
* from bus addresses to Logical PIO addresses.
*
*/
static int hisi_lpc_acpi_probe(struct device *hostdev)
{
int ret;
/* Only consider the children of the host */
ret = acpi_dev_for_each_child(ACPI_COMPANION(hostdev),
hisi_lpc_acpi_add_child, hostdev);
if (ret)
hisi_lpc_acpi_remove(hostdev);
return ret;
}
#else
static int hisi_lpc_acpi_probe(struct device *dev)
{
return -ENODEV;
}
static void hisi_lpc_acpi_remove(struct device *hostdev)
{
}
#endif // CONFIG_ACPI
/*
* hisi_lpc_probe - the probe callback function for hisi lpc host,
* will finish all the initialization.
* @pdev: the platform device corresponding to hisi lpc host
*
* Returns 0 on success, non-zero on fail.
*/
static int hisi_lpc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct logic_pio_hwaddr *range;
struct hisi_lpc_dev *lpcdev;
resource_size_t io_end;
int ret;
lpcdev = devm_kzalloc(dev, sizeof(*lpcdev), GFP_KERNEL);
if (!lpcdev)
return -ENOMEM;
spin_lock_init(&lpcdev->cycle_lock);
lpcdev->membase = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(lpcdev->membase))
return PTR_ERR(lpcdev->membase);
range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL);
if (!range)
return -ENOMEM;
range->fwnode = dev_fwnode(dev);
range->flags = LOGIC_PIO_INDIRECT;
range->size = PIO_INDIRECT_SIZE;
range->hostdata = lpcdev;
range->ops = &hisi_lpc_ops;
lpcdev->io_host = range;
ret = logic_pio_register_range(range);
if (ret) {
dev_err(dev, "register IO range failed (%d)!\n", ret);
return ret;
}
/* register the LPC host PIO resources */
if (is_acpi_device_node(range->fwnode))
ret = hisi_lpc_acpi_probe(dev);
else
ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
if (ret) {
logic_pio_unregister_range(range);
return ret;
}
dev_set_drvdata(dev, lpcdev);
io_end = lpcdev->io_host->io_start + lpcdev->io_host->size;
dev_info(dev, "registered range [%pa - %pa]\n",
&lpcdev->io_host->io_start, &io_end);
return ret;
}
static void hisi_lpc_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct hisi_lpc_dev *lpcdev = dev_get_drvdata(dev);
struct logic_pio_hwaddr *range = lpcdev->io_host;
if (is_acpi_device_node(range->fwnode))
hisi_lpc_acpi_remove(dev);
else
of_platform_depopulate(dev);
logic_pio_unregister_range(range);
}
static const struct of_device_id hisi_lpc_of_match[] = {
{ .compatible = "hisilicon,hip06-lpc", },
{ .compatible = "hisilicon,hip07-lpc", },
{}
};
static const struct acpi_device_id hisi_lpc_acpi_match[] = {
{"HISI0191"},
{}
};
static struct platform_driver hisi_lpc_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = hisi_lpc_of_match,
.acpi_match_table = hisi_lpc_acpi_match,
},
.probe = hisi_lpc_probe,
.remove_new = hisi_lpc_remove,
};
builtin_platform_driver(hisi_lpc_driver);