u-boot/drivers/pinctrl/pinctrl-single.c
Simon Glass 4d159b6f84 pinctrl: Avoid coverity warning when checking width
The width is set up in single_of_to_plat() and can only have three values,
all of which result in a non-zero divisor. Add a comment.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Coverity (CID: 331154)
2021-07-15 18:42:05 -04:00

554 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) EETS GmbH, 2017, Felix Brack <f.brack@eets.ch>
* Copyright (C) 2021 Dario Binacchi <dariobin@libero.it>
*/
#include <common.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <dm/devres.h>
#include <dm/pinctrl.h>
#include <linux/libfdt.h>
#include <linux/list.h>
#include <asm/io.h>
#include <sort.h>
/**
* struct single_pdata - platform data
* @base: first configuration register
* @offset: index of last configuration register
* @mask: configuration-value mask bits
* @width: configuration register bit width
* @bits_per_mux: true if one register controls more than one pin
*/
struct single_pdata {
fdt_addr_t base;
int offset;
u32 mask;
u32 width;
bool bits_per_mux;
};
/**
* struct single_func - pinctrl function
* @node: list node
* @name: pinctrl function name
* @npins: number of entries in pins array
* @pins: pins array
*/
struct single_func {
struct list_head node;
const char *name;
unsigned int npins;
unsigned int *pins;
};
/**
* struct single_priv - private data
* @bits_per_pin: number of bits per pin
* @npins: number of selectable pins
* @pin_name: temporary buffer to store the pin name
*/
struct single_priv {
#if (IS_ENABLED(CONFIG_SANDBOX))
u32 *sandbox_regs;
#endif
unsigned int bits_per_pin;
unsigned int npins;
char pin_name[PINNAME_SIZE];
struct list_head functions;
};
/**
* struct single_fdt_pin_cfg - pin configuration
*
* This structure is used for the pin configuration parameters in case
* the register controls only one pin.
*
* @reg: configuration register offset
* @val: configuration register value
*/
struct single_fdt_pin_cfg {
fdt32_t reg;
fdt32_t val;
};
/**
* struct single_fdt_bits_cfg - pin configuration
*
* This structure is used for the pin configuration parameters in case
* the register controls more than one pin.
*
* @reg: configuration register offset
* @val: configuration register value
* @mask: configuration register mask
*/
struct single_fdt_bits_cfg {
fdt32_t reg;
fdt32_t val;
fdt32_t mask;
};
#if (!IS_ENABLED(CONFIG_SANDBOX))
static unsigned int single_read(struct udevice *dev, fdt_addr_t reg)
{
struct single_pdata *pdata = dev_get_plat(dev);
switch (pdata->width) {
case 8:
return readb(reg);
case 16:
return readw(reg);
default: /* 32 bits */
return readl(reg);
}
return readb(reg);
}
static void single_write(struct udevice *dev, unsigned int val, fdt_addr_t reg)
{
struct single_pdata *pdata = dev_get_plat(dev);
switch (pdata->width) {
case 8:
writeb(val, reg);
break;
case 16:
writew(val, reg);
break;
default: /* 32 bits */
writel(val, reg);
}
}
#else /* CONFIG_SANDBOX */
static unsigned int single_read(struct udevice *dev, fdt_addr_t reg)
{
struct single_priv *priv = dev_get_priv(dev);
return priv->sandbox_regs[reg];
}
static void single_write(struct udevice *dev, unsigned int val, fdt_addr_t reg)
{
struct single_priv *priv = dev_get_priv(dev);
priv->sandbox_regs[reg] = val;
}
#endif /* CONFIG_SANDBOX */
/**
* single_get_pin_by_offset() - get a pin based on the register offset
* @dev: single driver instance
* @offset: register offset from the base
*/
static int single_get_pin_by_offset(struct udevice *dev, unsigned int offset)
{
struct single_pdata *pdata = dev_get_plat(dev);
struct single_priv *priv = dev_get_priv(dev);
if (offset > pdata->offset) {
dev_err(dev, "mux offset out of range: 0x%x (0x%x)\n",
offset, pdata->offset);
return -EINVAL;
}
if (pdata->bits_per_mux)
return (offset * BITS_PER_BYTE) / priv->bits_per_pin;
return offset / (pdata->width / BITS_PER_BYTE);
}
static int single_get_offset_by_pin(struct udevice *dev, unsigned int pin)
{
struct single_pdata *pdata = dev_get_plat(dev);
struct single_priv *priv = dev_get_priv(dev);
unsigned int mux_bytes;
if (pin >= priv->npins)
return -EINVAL;
mux_bytes = pdata->width / BITS_PER_BYTE;
if (pdata->bits_per_mux) {
int byte_num;
byte_num = (priv->bits_per_pin * pin) / BITS_PER_BYTE;
return (byte_num / mux_bytes) * mux_bytes;
}
return pin * mux_bytes;
}
static const char *single_get_pin_function(struct udevice *dev,
unsigned int pin)
{
struct single_priv *priv = dev_get_priv(dev);
struct single_func *func;
int i;
list_for_each_entry(func, &priv->functions, node) {
for (i = 0; i < func->npins; i++) {
if (pin == func->pins[i])
return func->name;
if (pin < func->pins[i])
break;
}
}
return NULL;
}
static int single_get_pin_muxing(struct udevice *dev, unsigned int pin,
char *buf, int size)
{
struct single_pdata *pdata = dev_get_plat(dev);
struct single_priv *priv = dev_get_priv(dev);
fdt_addr_t reg;
const char *fname;
unsigned int val;
int offset, pin_shift = 0;
offset = single_get_offset_by_pin(dev, pin);
if (offset < 0)
return offset;
reg = pdata->base + offset;
val = single_read(dev, reg);
if (pdata->bits_per_mux)
pin_shift = pin % (pdata->width / priv->bits_per_pin) *
priv->bits_per_pin;
val &= (pdata->mask << pin_shift);
fname = single_get_pin_function(dev, pin);
snprintf(buf, size, "%pa 0x%08x %s", &reg, val,
fname ? fname : "UNCLAIMED");
return 0;
}
static struct single_func *single_allocate_function(struct udevice *dev,
unsigned int group_pins)
{
struct single_func *func;
func = devm_kmalloc(dev, sizeof(*func), GFP_KERNEL);
if (!func)
return ERR_PTR(-ENOMEM);
func->pins = devm_kmalloc(dev, sizeof(unsigned int) * group_pins,
GFP_KERNEL);
if (!func->pins)
return ERR_PTR(-ENOMEM);
return func;
}
static int single_pin_compare(const void *s1, const void *s2)
{
int pin1 = *(const unsigned int *)s1;
int pin2 = *(const unsigned int *)s2;
return pin1 - pin2;
}
/**
* single_configure_pins() - Configure pins based on FDT data
*
* @dev: Pointer to single pin configuration device which is the parent of
* the pins node holding the pin configuration data.
* @pins: Pointer to the first element of an array of register/value pairs
* of type 'struct single_fdt_pin_cfg'. Each such pair describes the
* the pin to be configured and the value to be used for configuration.
* This pointer points to a 'pinctrl-single,pins' property in the
* device-tree.
* @size: Size of the 'pins' array in bytes.
* The number of register/value pairs in the 'pins' array therefore
* equals to 'size / sizeof(struct single_fdt_pin_cfg)'.
* @fname: Function name.
*/
static int single_configure_pins(struct udevice *dev,
const struct single_fdt_pin_cfg *pins,
int size, const char *fname)
{
struct single_pdata *pdata = dev_get_plat(dev);
struct single_priv *priv = dev_get_priv(dev);
int n, pin, count = size / sizeof(struct single_fdt_pin_cfg);
struct single_func *func;
phys_addr_t reg;
u32 offset, val;
/* If function mask is null, needn't enable it. */
if (!pdata->mask)
return 0;
func = single_allocate_function(dev, count);
if (IS_ERR(func))
return PTR_ERR(func);
func->name = fname;
func->npins = 0;
for (n = 0; n < count; n++, pins++) {
offset = fdt32_to_cpu(pins->reg);
if (offset > pdata->offset) {
dev_err(dev, " invalid register offset 0x%x\n",
offset);
continue;
}
reg = pdata->base + offset;
val = fdt32_to_cpu(pins->val) & pdata->mask;
pin = single_get_pin_by_offset(dev, offset);
if (pin < 0) {
dev_err(dev, " failed to get pin by offset %x\n",
offset);
continue;
}
single_write(dev, (single_read(dev, reg) & ~pdata->mask) | val,
reg);
dev_dbg(dev, " reg/val %pa/0x%08x\n", &reg, val);
func->pins[func->npins] = pin;
func->npins++;
}
qsort(func->pins, func->npins, sizeof(func->pins[0]),
single_pin_compare);
list_add(&func->node, &priv->functions);
return 0;
}
static int single_configure_bits(struct udevice *dev,
const struct single_fdt_bits_cfg *pins,
int size, const char *fname)
{
struct single_pdata *pdata = dev_get_plat(dev);
struct single_priv *priv = dev_get_priv(dev);
int n, pin, count = size / sizeof(struct single_fdt_bits_cfg);
int npins_in_reg, pin_num_from_lsb;
struct single_func *func;
phys_addr_t reg;
u32 offset, val, mask, bit_pos, val_pos, mask_pos, submask;
/* If function mask is null, needn't enable it. */
if (!pdata->mask)
return 0;
npins_in_reg = pdata->width / priv->bits_per_pin;
func = single_allocate_function(dev, count * npins_in_reg);
if (IS_ERR(func))
return PTR_ERR(func);
func->name = fname;
func->npins = 0;
for (n = 0; n < count; n++, pins++) {
offset = fdt32_to_cpu(pins->reg);
if (offset > pdata->offset) {
dev_dbg(dev, " invalid register offset 0x%x\n",
offset);
continue;
}
reg = pdata->base + offset;
pin = single_get_pin_by_offset(dev, offset);
if (pin < 0) {
dev_err(dev, " failed to get pin by offset 0x%pa\n",
&reg);
continue;
}
mask = fdt32_to_cpu(pins->mask);
val = fdt32_to_cpu(pins->val) & mask;
single_write(dev, (single_read(dev, reg) & ~mask) | val, reg);
dev_dbg(dev, " reg/val %pa/0x%08x\n", &reg, val);
while (mask) {
bit_pos = __ffs(mask);
pin_num_from_lsb = bit_pos / priv->bits_per_pin;
mask_pos = pdata->mask << bit_pos;
val_pos = val & mask_pos;
submask = mask & mask_pos;
if ((mask & mask_pos) == 0) {
dev_err(dev, "Invalid mask at 0x%x\n", offset);
break;
}
mask &= ~mask_pos;
if (submask != mask_pos) {
dev_warn(dev,
"Invalid submask 0x%x at 0x%x\n",
submask, offset);
continue;
}
func->pins[func->npins] = pin + pin_num_from_lsb;
func->npins++;
}
}
qsort(func->pins, func->npins, sizeof(func->pins[0]),
single_pin_compare);
list_add(&func->node, &priv->functions);
return 0;
}
static int single_set_state(struct udevice *dev,
struct udevice *config)
{
const struct single_fdt_pin_cfg *prop;
const struct single_fdt_bits_cfg *prop_bits;
int len;
prop = dev_read_prop(config, "pinctrl-single,pins", &len);
if (prop) {
dev_dbg(dev, "configuring pins for %s\n", config->name);
if (len % sizeof(struct single_fdt_pin_cfg)) {
dev_dbg(dev, " invalid pin configuration in fdt\n");
return -FDT_ERR_BADSTRUCTURE;
}
single_configure_pins(dev, prop, len, config->name);
return 0;
}
/* pinctrl-single,pins not found so check for pinctrl-single,bits */
prop_bits = dev_read_prop(config, "pinctrl-single,bits", &len);
if (prop_bits) {
dev_dbg(dev, "configuring pins for %s\n", config->name);
if (len % sizeof(struct single_fdt_bits_cfg)) {
dev_dbg(dev, " invalid bits configuration in fdt\n");
return -FDT_ERR_BADSTRUCTURE;
}
single_configure_bits(dev, prop_bits, len, config->name);
return 0;
}
/* Neither 'pinctrl-single,pins' nor 'pinctrl-single,bits' were found */
return len;
}
static const char *single_get_pin_name(struct udevice *dev,
unsigned int selector)
{
struct single_priv *priv = dev_get_priv(dev);
if (selector >= priv->npins)
snprintf(priv->pin_name, PINNAME_SIZE, "Error");
else
snprintf(priv->pin_name, PINNAME_SIZE, "PIN%u", selector);
return priv->pin_name;
}
static int single_get_pins_count(struct udevice *dev)
{
struct single_priv *priv = dev_get_priv(dev);
return priv->npins;
}
static int single_probe(struct udevice *dev)
{
struct single_pdata *pdata = dev_get_plat(dev);
struct single_priv *priv = dev_get_priv(dev);
u32 size;
INIT_LIST_HEAD(&priv->functions);
size = pdata->offset + pdata->width / BITS_PER_BYTE;
#if (CONFIG_IS_ENABLED(SANDBOX))
priv->sandbox_regs =
devm_kzalloc(dev, size * sizeof(*priv->sandbox_regs),
GFP_KERNEL);
if (!priv->sandbox_regs)
return -ENOMEM;
#endif
/* looks like a possible divide by 0, but data->width avoids this */
priv->npins = size / (pdata->width / BITS_PER_BYTE);
if (pdata->bits_per_mux) {
if (!pdata->mask) {
dev_err(dev, "function mask needs to be non-zero\n");
return -EINVAL;
}
priv->bits_per_pin = fls(pdata->mask);
priv->npins *= (pdata->width / priv->bits_per_pin);
}
dev_dbg(dev, "%d pins\n", priv->npins);
return 0;
}
static int single_of_to_plat(struct udevice *dev)
{
fdt_addr_t addr;
fdt_size_t size;
struct single_pdata *pdata = dev_get_plat(dev);
int ret;
ret = dev_read_u32(dev, "pinctrl-single,register-width", &pdata->width);
if (ret) {
dev_err(dev, "missing register width\n");
return ret;
}
switch (pdata->width) {
case 8:
case 16:
case 32:
break;
default:
dev_err(dev, "wrong register width\n");
return -EINVAL;
}
addr = dev_read_addr_size_index(dev, 0, &size);
if (addr == FDT_ADDR_T_NONE) {
dev_err(dev, "failed to get base register address\n");
return -EINVAL;
}
pdata->offset = size - pdata->width / BITS_PER_BYTE;
pdata->base = addr;
ret = dev_read_u32(dev, "pinctrl-single,function-mask", &pdata->mask);
if (ret) {
pdata->mask = 0;
dev_warn(dev, "missing function register mask\n");
}
pdata->bits_per_mux = dev_read_bool(dev, "pinctrl-single,bit-per-mux");
return 0;
}
const struct pinctrl_ops single_pinctrl_ops = {
.get_pins_count = single_get_pins_count,
.get_pin_name = single_get_pin_name,
.set_state = single_set_state,
.get_pin_muxing = single_get_pin_muxing,
};
static const struct udevice_id single_pinctrl_match[] = {
{ .compatible = "pinctrl-single" },
{ /* sentinel */ }
};
U_BOOT_DRIVER(single_pinctrl) = {
.name = "single-pinctrl",
.id = UCLASS_PINCTRL,
.of_match = single_pinctrl_match,
.ops = &single_pinctrl_ops,
.plat_auto = sizeof(struct single_pdata),
.priv_auto = sizeof(struct single_priv),
.of_to_plat = single_of_to_plat,
.probe = single_probe,
};