diff options
Diffstat (limited to 'driver')
| -rw-r--r-- | driver/Makefile | 14 | ||||
| -rw-r--r-- | driver/main.c | 20 | ||||
| -rw-r--r-- | driver/platform.c | 57 |
3 files changed, 70 insertions, 21 deletions
diff --git a/driver/Makefile b/driver/Makefile index 7de7424..f9cb359 100644 --- a/driver/Makefile +++ b/driver/Makefile @@ -9,9 +9,17 @@ obj-m += lork.o lork-y += main.o lork-y += platform.o -all: +# utility +ifneq ($(shell id -u),0) +AS_ROOT := sudo -n +endif +.PHONY: FORCE + +lork.ko: FORCE $(MAKE) -C $(KERNEL) M=$(PWD) modules +all: lork.ko FORCE + # the generated compile_commands.json needs to be edited to point to the kernel # folder as working directory because the include paths are relative compile_commands.json: @@ -19,3 +27,7 @@ compile_commands.json: jq --arg dir $(KERNEL) '.[].directory = $$dir' $@.tmp > $@ $(RM) $@.tmp +poke: lork.ko FORCE + $(AS_ROOT) insmod $< + $(AS_ROOT) rmmod $< + diff --git a/driver/main.c b/driver/main.c index a322616..76ba1d8 100644 --- a/driver/main.c +++ b/driver/main.c @@ -23,26 +23,6 @@ struct platform_driver lork_driver = { static int mod_init(void) { printk("%s()\n", __PRETTY_FUNCTION__); - - // // configure gpio mux - // uint32_t* conf_gpmc_a3 = ioremap(TI_AM335X_CM_GPMC_A3_ADDR, sizeof(ti_am335x_word_t)); - // if (conf_gpmc_a3 == NULL) - // return -EINVAL; - // barrier(); - // uint32_t val = ioread32(conf_gpmc_a3); rmb(); - // val &= ~0x7; - // val |= 0x7; - // iowrite32(val, conf_gpmc_a3); wmb(); - // iounmap(conf_gpmc_a3); - - // // configure output pin - // ti_am335x_word_t* gpio1 = ioremap(TI_AM335X_GPIO1_ADDR, GPIO_REG_SIZE); - // barrier(); - // ti_am335x_word_t oe_reg = ioread32(gpio1 + GPIO_OE); rmb(); - // oe_reg &= ~(1<<PIN); // 0=output - // iowrite32(oe_reg, gpio1 + GPIO_OE); wmb(); - // iounmap(gpio1); - return platform_driver_register(&lork_driver); } diff --git a/driver/platform.c b/driver/platform.c index 85aefec..da84064 100644 --- a/driver/platform.c +++ b/driver/platform.c @@ -1,6 +1,63 @@ #include "platform.h" +#include <linux/types.h> +#include <linux/of.h> + +#include <dt-bindings/gpio/gpio.h> + +// NOTE: i believe any nonzero return value for the probe function is +// recognized as an error because of +// <https://github.com/torvalds/linux/blob/a5131c3fdf2608f1c15f3809e201cf540eb28489/drivers/base/platform.c#L1004> int lork_probe(struct platform_device* dev) { + // read gpios field from device tree + uint32_t dt_gpios[3]; + of_property_read_u32_array(dev->dev.of_node, "gpios", dt_gpios, 3); + + struct device_node* gpio1 = of_find_node_by_phandle(dt_gpios[0]); + uint32_t pin = dt_gpios[1]; + uint32_t gpio_mode = dt_gpios[2]; + printk("lork: configure pin %u w/ mode 0x%02x\n", pin, gpio_mode); + + // find the multiplexer that controls pin + size_t len = of_property_count_u32_elems(gpio1, "gpio-ranges"); + struct device_node* am33xx_pinmux = NULL; + for (size_t i = 0; i < len; i += 4) { + uint32_t phandle, pin_start, pin_offset, pin_size; + of_property_read_u32_index(gpio1, "gpio-ranges", i+0, &phandle); + of_property_read_u32_index(gpio1, "gpio-ranges", i+1, &pin_start); + of_property_read_u32_index(gpio1, "gpio-ranges", i+2, &pin_offset); + of_property_read_u32_index(gpio1, "gpio-ranges", i+3, &pin_size); + + // get phandle for multiplexer corresponding to configured pin number + if (pin_start > pin || pin >= pin_start + pin_size) continue; + + am33xx_pinmux = of_find_node_by_phandle(phandle); + printk("0x%02x, %u -> %u + %u\n", phandle, pin_start, pin_offset, pin_size); + break; + } + if (am33xx_pinmux == NULL) return EINVAL; + + // TODO: ??? + + // // configure gpio mux + // uint32_t* conf_gpmc_a3 = ioremap(TI_AM335X_CM_GPMC_A3_ADDR, sizeof(ti_am335x_word_t)); + // if (conf_gpmc_a3 == NULL) + // return -EINVAL; + // barrier(); + // uint32_t val = ioread32(conf_gpmc_a3); rmb(); + // val &= ~0x7; + // val |= 0x7; + // iowrite32(val, conf_gpmc_a3); wmb(); + // iounmap(conf_gpmc_a3); + + // // configure output pin + // ti_am335x_word_t* gpio1 = ioremap(TI_AM335X_GPIO1_ADDR, GPIO_REG_SIZE); + // barrier(); + // ti_am335x_word_t oe_reg = ioread32(gpio1 + GPIO_OE); rmb(); + // oe_reg &= ~(1<<PIN); // 0=output + // iowrite32(oe_reg, gpio1 + GPIO_OE); wmb(); + // iounmap(gpio1); + printk("%s(%s)\n", __PRETTY_FUNCTION__, dev->name); return 0; } |