This patch creates of_count_phandle_with_args(), a new function for counting the number of phandle+argument tuples in a given property. This is better than the existing method of parsing each phandle individually until parsing fails which is a horribly slow way to do the count.
It also converts of_gpio_named_count() to use the new function instead of using the above described horrible method. This also requires the return value of of_gpio_count() & of_gpio_named_count() from 'unsigned int' to 'int' so that it can return an error code. All the users of that function are fixed up to correctly handle a negative return value. Tested on ARM using the selftest code. Signed-off-by: Grant Likely <grant.lik...@secretlab.ca> Cc: Linus Walleij <linus.wall...@linaro.org> Cc: Rob Herring <rob.herr...@calxeda.com> Cc: Andreas Larsson <andr...@gaisler.com> --- drivers/gpio/gpiolib-of.c | 35 --------------------- drivers/hwmon/gpio-fan.c | 4 +-- drivers/input/keyboard/matrix_keypad.c | 8 ++--- drivers/net/phy/mdio-mux-gpio.c | 4 +-- drivers/of/base.c | 54 +++++++++++++++++++++++++++----- drivers/of/selftest.c | 23 +++++++++++++- drivers/spi/spi-fsl-spi.c | 4 +-- drivers/spi/spi-oc-tiny.c | 8 ++--- drivers/spi/spi-ppc4xx.c | 4 +-- include/linux/of.h | 9 ++++++ include/linux/of_gpio.h | 30 +++++++++++++++--- 11 files changed, 118 insertions(+), 65 deletions(-) diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index d542a14..dd8a212 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -89,41 +89,6 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname, EXPORT_SYMBOL(of_get_named_gpio_flags); /** - * of_gpio_named_count - Count GPIOs for a device - * @np: device node to count GPIOs for - * @propname: property name containing gpio specifier(s) - * - * The function returns the count of GPIOs specified for a node. - * - * Note that the empty GPIO specifiers counts too. For example, - * - * gpios = <0 - * &pio1 1 2 - * 0 - * &pio2 3 4>; - * - * defines four GPIOs (so this function will return 4), two of which - * are not specified. - */ -unsigned int of_gpio_named_count(struct device_node *np, const char* propname) -{ - unsigned int cnt = 0; - - do { - int ret; - - ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", - cnt, NULL); - /* A hole in the gpios = <> counts anyway. */ - if (ret < 0 && ret != -EEXIST) - break; - } while (++cnt); - - return cnt; -} -EXPORT_SYMBOL(of_gpio_named_count); - -/** * of_gpio_simple_xlate - translate gpio_spec to the GPIO number and flags * @gc: pointer to the gpio_chip structure * @np: device node of the GPIO chip diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index 4e04c12..3978194 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -422,7 +422,7 @@ static int gpio_fan_get_of_pdata(struct device *dev, /* Fill GPIO pin array */ pdata->num_ctrl = of_gpio_count(node); - if (!pdata->num_ctrl) { + if (pdata->num_ctrl <= 0) { dev_err(dev, "gpios DT property empty / missing"); return -ENODEV; } @@ -477,7 +477,7 @@ static int gpio_fan_get_of_pdata(struct device *dev, pdata->speed = speed; /* Alarm GPIO if one exists */ - if (of_gpio_named_count(node, "alarm-gpios")) { + if (of_gpio_named_count(node, "alarm-gpios") > 0) { struct gpio_fan_alarm *alarm; int val; enum of_gpio_flags flags; diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c index f4ff0dd..71d7719 100644 --- a/drivers/input/keyboard/matrix_keypad.c +++ b/drivers/input/keyboard/matrix_keypad.c @@ -403,7 +403,7 @@ matrix_keypad_parse_dt(struct device *dev) struct matrix_keypad_platform_data *pdata; struct device_node *np = dev->of_node; unsigned int *gpios; - int i; + int i, nrow, ncol; if (!np) { dev_err(dev, "device lacks DT data\n"); @@ -416,9 +416,9 @@ matrix_keypad_parse_dt(struct device *dev) return ERR_PTR(-ENOMEM); } - pdata->num_row_gpios = of_gpio_named_count(np, "row-gpios"); - pdata->num_col_gpios = of_gpio_named_count(np, "col-gpios"); - if (!pdata->num_row_gpios || !pdata->num_col_gpios) { + pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios"); + pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios"); + if (nrow <= 0 || ncol <= 0) { dev_err(dev, "number of keypad rows/columns not specified\n"); return ERR_PTR(-EINVAL); } diff --git a/drivers/net/phy/mdio-mux-gpio.c b/drivers/net/phy/mdio-mux-gpio.c index 0c9accb..e91d7d7 100644 --- a/drivers/net/phy/mdio-mux-gpio.c +++ b/drivers/net/phy/mdio-mux-gpio.c @@ -53,7 +53,7 @@ static int mdio_mux_gpio_probe(struct platform_device *pdev) { enum of_gpio_flags f; struct mdio_mux_gpio_state *s; - unsigned int num_gpios; + int num_gpios; unsigned int n; int r; @@ -61,7 +61,7 @@ static int mdio_mux_gpio_probe(struct platform_device *pdev) return -ENODEV; num_gpios = of_gpio_count(pdev->dev.of_node); - if (num_gpios == 0 || num_gpios > MDIO_MUX_GPIO_MAX_BITS) + if (num_gpios <= 0 || num_gpios > MDIO_MUX_GPIO_MAX_BITS) return -ENODEV; s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL); diff --git a/drivers/of/base.c b/drivers/of/base.c index 2390ddb..e1120a2 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1025,12 +1025,13 @@ EXPORT_SYMBOL(of_parse_phandle); * To get a device_node of the `node2' node you may call this: * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args); */ -int of_parse_phandle_with_args(const struct device_node *np, const char *list_name, - const char *cells_name, int index, - struct of_phandle_args *out_args) +static int __of_parse_phandle_with_args(const struct device_node *np, + const char *list_name, + const char *cells_name, int index, + struct of_phandle_args *out_args) { const __be32 *list, *list_end; - int size, cur_index = 0; + int rc = 0, size, cur_index = 0; uint32_t count = 0; struct device_node *node = NULL; phandle phandle; @@ -1059,12 +1060,14 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na if (!node) { pr_err("%s: could not find phandle\n", np->full_name); + rc = -EINVAL; break; } if (of_property_read_u32(node, cells_name, &count)) { pr_err("%s: could not get %s for %s\n", np->full_name, cells_name, node->full_name); + rc = -EINVAL; break; } @@ -1075,6 +1078,7 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na if (list + count > list_end) { pr_err("%s: arguments longer than property\n", np->full_name); + rc = -EINVAL; break; } } @@ -1086,8 +1090,10 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na * or return -ENOENT for an empty entry. */ if (cur_index == index) { - if (!phandle) - return -ENOENT; + if (!phandle) { + rc = -ENOENT; + break; + } if (out_args) { int i; @@ -1098,22 +1104,54 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na for (i = 0; i < count; i++) out_args->args[i] = be32_to_cpup(list++); } - return 0; + + rc = 0; + break; } of_node_put(node); node = NULL; list += count; cur_index++; + rc = cur_index; } /* Loop exited without finding a valid entry; return an error */ if (node) of_node_put(node); - return -EINVAL; + return rc; +} + +int of_parse_phandle_with_args(const struct device_node *np, const char *list_name, + const char *cells_name, int index, + struct of_phandle_args *out_args) +{ + return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args); } EXPORT_SYMBOL(of_parse_phandle_with_args); +/** + * of_count_phandle_with_args() - Find the number of phandles references in a property + * @np: pointer to a device tree node containing a list + * @list_name: property name that contains a list + * @cells_name: property name that specifies phandles' arguments count + * + * Returns the number of phandle + argument tuples within a property. It + * is a typical pattern to encode a list of phandle and variable + * arguments into a single property. The number of arguments is encoded + * by a property in the phandle-target node. For example, a gpios + * property would contain a list of GPIO specifies consisting of a + * phandle and 1 or more arguments. The number of arguments are + * determined by the #gpio-cells property in the node pointed to by the + * phandle. + */ +int of_count_phandle_with_args(const struct device_node *np, const char *list_name, + const char *cells_name) +{ + return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL); +} +EXPORT_SYMBOL(of_count_phandle_with_args); + #if defined(CONFIG_OF_DYNAMIC) static int of_property_notify(int action, struct device_node *np, struct property *prop) diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c index f24ffd7..e3a03d5 100644 --- a/drivers/of/selftest.c +++ b/drivers/of/selftest.c @@ -35,6 +35,11 @@ static void __init of_selftest_parse_phandle_with_args(void) return; } + rc = of_count_phandle_with_args(np, "phandle-list", "#phandle-cells"); + if (rc != 7) + pr_err("of_count_phandle_with_args() returned %i, expected 7\n", rc); + passed_all &= (rc == 7); + for (i = 0; i < 7; i++) { bool passed = true; rc = of_parse_phandle_with_args(np, "phandle-list", @@ -100,22 +105,38 @@ static void __init of_selftest_parse_phandle_with_args(void) /* Check for missing list property */ rc = of_parse_phandle_with_args(np, "phandle-list-missing", "#phandle-cells", 0, &args); - passed_all &= (rc == -EINVAL); + passed_all &= (rc == -ENOENT); + rc = of_count_phandle_with_args(np, "phandle-list-missing", + "#phandle-cells"); + passed_all &= (rc == -ENOENT); + pr_err("rc = %i\n", rc); /* Check for missing cells property */ rc = of_parse_phandle_with_args(np, "phandle-list", "#phandle-cells-missing", 0, &args); passed_all &= (rc == -EINVAL); + rc = of_count_phandle_with_args(np, "phandle-list", + "#phandle-cells-missing"); + passed_all &= (rc == -EINVAL); + pr_err("rc = %i\n", rc); /* Check for bad phandle in list */ rc = of_parse_phandle_with_args(np, "phandle-list-bad-phandle", "#phandle-cells", 0, &args); passed_all &= (rc == -EINVAL); + rc = of_count_phandle_with_args(np, "phandle-list-bad-phandle", + "#phandle-cells"); + passed_all &= (rc == -EINVAL); + pr_err("rc = %i\n", rc); /* Check for incorrectly formed argument list */ rc = of_parse_phandle_with_args(np, "phandle-list-bad-args", "#phandle-cells", 1, &args); passed_all &= (rc == -EINVAL); + rc = of_count_phandle_with_args(np, "phandle-list-bad-args", + "#phandle-cells"); + passed_all &= (rc == -EINVAL); + pr_err("rc = %i\n", rc); pr_info("end - %s\n", passed_all ? "PASS" : "FAIL"); } diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 1a7f635..086a9ee 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -947,12 +947,12 @@ static int of_fsl_spi_get_chipselects(struct device *dev) struct device_node *np = dev->of_node; struct fsl_spi_platform_data *pdata = dev->platform_data; struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata); - unsigned int ngpios; + int ngpios; int i = 0; int ret; ngpios = of_gpio_count(np); - if (!ngpios) { + if (ngpios <= 0) { /* * SPI w/o chip-select line. One SPI device is still permitted * though. diff --git a/drivers/spi/spi-oc-tiny.c b/drivers/spi/spi-oc-tiny.c index 432e66e..cb2e284 100644 --- a/drivers/spi/spi-oc-tiny.c +++ b/drivers/spi/spi-oc-tiny.c @@ -54,7 +54,7 @@ struct tiny_spi { unsigned int txc, rxc; const u8 *txp; u8 *rxp; - unsigned int gpio_cs_count; + int gpio_cs_count; int *gpio_cs; }; @@ -74,7 +74,7 @@ static void tiny_spi_chipselect(struct spi_device *spi, int is_active) { struct tiny_spi *hw = tiny_spi_to_hw(spi); - if (hw->gpio_cs_count) { + if (hw->gpio_cs_count > 0) { gpio_set_value(hw->gpio_cs[spi->chip_select], (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); } @@ -254,7 +254,7 @@ static int tiny_spi_of_probe(struct platform_device *pdev) if (!np) return 0; hw->gpio_cs_count = of_gpio_count(np); - if (hw->gpio_cs_count) { + if (hw->gpio_cs_count > 0) { hw->gpio_cs = devm_kzalloc(&pdev->dev, hw->gpio_cs_count * sizeof(unsigned int), GFP_KERNEL); @@ -352,7 +352,7 @@ static int tiny_spi_probe(struct platform_device *pdev) goto exit_gpio; gpio_direction_output(hw->gpio_cs[i], 1); } - hw->bitbang.master->num_chipselect = max(1U, hw->gpio_cs_count); + hw->bitbang.master->num_chipselect = max(1, hw->gpio_cs_count); /* register our spi controller */ err = spi_bitbang_start(&hw->bitbang); diff --git a/drivers/spi/spi-ppc4xx.c b/drivers/spi/spi-ppc4xx.c index 7a85f22..af3e6e7 100644 --- a/drivers/spi/spi-ppc4xx.c +++ b/drivers/spi/spi-ppc4xx.c @@ -419,7 +419,7 @@ static int __init spi_ppc4xx_of_probe(struct platform_device *op) * This includes both "null" gpio's and real ones. */ num_gpios = of_gpio_count(np); - if (num_gpios) { + if (num_gpios > 0) { int i; hw->gpios = kzalloc(sizeof(int) * num_gpios, GFP_KERNEL); @@ -471,7 +471,7 @@ static int __init spi_ppc4xx_of_probe(struct platform_device *op) SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST; /* this many pins in all GPIO controllers */ - bbp->master->num_chipselect = num_gpios; + bbp->master->num_chipselect = num_gpios > 0 ? num_gpios : 0; /* Get the clock for the OPB */ opbnp = of_find_compatible_node(NULL, NULL, "ibm,opb"); diff --git a/include/linux/of.h b/include/linux/of.h index 5ebcc5c..fabc610 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -277,6 +277,8 @@ extern struct device_node *of_parse_phandle(const struct device_node *np, extern int of_parse_phandle_with_args(const struct device_node *np, const char *list_name, const char *cells_name, int index, struct of_phandle_args *out_args); +extern int of_count_phandle_with_args(const struct device_node *np, + const char *list_name, const char *cells_name); extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)); extern int of_alias_get_id(struct device_node *np, const char *stem); @@ -467,6 +469,13 @@ static inline int of_parse_phandle_with_args(struct device_node *np, return -ENOSYS; } +static inline int of_parse_count_with_args(struct device_node *np, + const char *list_name, + const char *cells_name) +{ + return -ENOSYS; +} + static inline int of_alias_get_id(struct device_node *np, const char *stem) { return -ENOSYS; diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h index c454f57..bdbe0f3 100644 --- a/include/linux/of_gpio.h +++ b/include/linux/of_gpio.h @@ -50,8 +50,28 @@ static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) extern int of_get_named_gpio_flags(struct device_node *np, const char *list_name, int index, enum of_gpio_flags *flags); -extern unsigned int of_gpio_named_count(struct device_node *np, - const char* propname); +/** + * of_gpio_named_count - Count GPIOs for a device + * @np: device node to count GPIOs for + * @propname: property name containing gpio specifier(s) + * + * The function returns the count of GPIOs specified for a node. + * + * Note that the empty GPIO specifiers counts too. For example, + * + * gpios = <0 + * &pio1 1 2 + * 0 + * &pio2 3 4>; + * + * defines four GPIOs (so this function will return 4), two of which + * are not specified. Returns -EINVAL for an incorrectly formed gpios + * property. + */ +static int of_gpio_named_count(struct device_node *np, const char* propname) +{ + return of_count_phandle_with_args(np, propname, "#gpio-cells"); +} extern int of_mm_gpiochip_add(struct device_node *np, struct of_mm_gpio_chip *mm_gc); @@ -71,10 +91,10 @@ static inline int of_get_named_gpio_flags(struct device_node *np, return -ENOSYS; } -static inline unsigned int of_gpio_named_count(struct device_node *np, +static inline int of_gpio_named_count(struct device_node *np, const char* propname) { - return 0; + return -ENOSYS; } static inline int of_gpio_simple_xlate(struct gpio_chip *gc, @@ -105,7 +125,7 @@ static inline void of_gpiochip_remove(struct gpio_chip *gc) { } * defines four GPIOs (so this function will return 4), two of which * are not specified. */ -static inline unsigned int of_gpio_count(struct device_node *np) +static inline int of_gpio_count(struct device_node *np) { return of_gpio_named_count(np, "gpios"); } -- 1.7.10.4 _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss