diff options
Diffstat (limited to 'drivers/spi/spi-gpio.c')
-rw-r--r-- | drivers/spi/spi-gpio.c | 227 |
1 files changed, 95 insertions, 132 deletions
diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 53b35c56a557..487ee55d26f7 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -35,20 +35,16 @@ * platform_device->driver_data ... points to spi_gpio * * spi->controller_state ... reserved for bitbang framework code - * spi->controller_data ... holds chipselect GPIO * * spi->master->dev.driver_data ... points to spi_gpio->bitbang */ struct spi_gpio { struct spi_bitbang bitbang; - struct spi_gpio_platform_data pdata; - struct platform_device *pdev; struct gpio_desc *sck; struct gpio_desc *miso; struct gpio_desc *mosi; struct gpio_desc **cs_gpios; - bool has_cs; }; /*----------------------------------------------------------------------*/ @@ -96,12 +92,6 @@ spi_to_spi_gpio(const struct spi_device *spi) return spi_gpio; } -static inline struct spi_gpio_platform_data *__pure -spi_to_pdata(const struct spi_device *spi) -{ - return &spi_to_spi_gpio(spi)->pdata; -} - /* These helpers are in turn called by the bitbang inlines */ static inline void setsck(const struct spi_device *spi, int is_on) { @@ -224,7 +214,7 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active) gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL); /* Drive chip select line, if we have one */ - if (spi_gpio->has_cs) { + if (spi_gpio->cs_gpios) { struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select]; /* SPI chip selects are normally active-low */ @@ -242,10 +232,12 @@ static int spi_gpio_setup(struct spi_device *spi) * The CS GPIOs have already been * initialized from the descriptor lookup. */ - cs = spi_gpio->cs_gpios[spi->chip_select]; - if (!spi->controller_state && cs) - status = gpiod_direction_output(cs, - !(spi->mode & SPI_CS_HIGH)); + if (spi_gpio->cs_gpios) { + cs = spi_gpio->cs_gpios[spi->chip_select]; + if (!spi->controller_state && cs) + status = gpiod_direction_output(cs, + !(spi->mode & SPI_CS_HIGH)); + } if (!status) status = spi_bitbang_setup(spi); @@ -296,40 +288,20 @@ static void spi_gpio_cleanup(struct spi_device *spi) * floating signals. (A weak pulldown would save power too, but many * drivers expect to see all-ones data as the no slave "response".) */ -static int spi_gpio_request(struct device *dev, - struct spi_gpio *spi_gpio, - unsigned int num_chipselects, - u16 *mflags) +static int spi_gpio_request(struct device *dev, struct spi_gpio *spi_gpio) { - int i; - spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW); if (IS_ERR(spi_gpio->mosi)) return PTR_ERR(spi_gpio->mosi); - if (!spi_gpio->mosi) - /* HW configuration without MOSI pin */ - *mflags |= SPI_MASTER_NO_TX; spi_gpio->miso = devm_gpiod_get_optional(dev, "miso", GPIOD_IN); if (IS_ERR(spi_gpio->miso)) return PTR_ERR(spi_gpio->miso); - /* - * No setting SPI_MASTER_NO_RX here - if there is only a MOSI - * pin connected the host can still do RX by changing the - * direction of the line. - */ spi_gpio->sck = devm_gpiod_get(dev, "sck", GPIOD_OUT_LOW); if (IS_ERR(spi_gpio->sck)) return PTR_ERR(spi_gpio->sck); - for (i = 0; i < num_chipselects; i++) { - spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", - i, GPIOD_OUT_HIGH); - if (IS_ERR(spi_gpio->cs_gpios[i])) - return PTR_ERR(spi_gpio->cs_gpios[i]); - } - return 0; } @@ -340,142 +312,134 @@ static const struct of_device_id spi_gpio_dt_ids[] = { }; MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids); -static int spi_gpio_probe_dt(struct platform_device *pdev) +static int spi_gpio_probe_dt(struct platform_device *pdev, + struct spi_master *master) { - int ret; - u32 tmp; - struct spi_gpio_platform_data *pdata; - struct device_node *np = pdev->dev.of_node; - const struct of_device_id *of_id = - of_match_device(spi_gpio_dt_ids, &pdev->dev); - - if (!of_id) - return 0; + master->dev.of_node = pdev->dev.of_node; + master->use_gpio_descriptors = true; - pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); - if (!pdata) - return -ENOMEM; + return 0; +} +#else +static inline int spi_gpio_probe_dt(struct platform_device *pdev, + struct spi_master *master) +{ + return 0; +} +#endif +static int spi_gpio_probe_pdata(struct platform_device *pdev, + struct spi_master *master) +{ + struct device *dev = &pdev->dev; + struct spi_gpio_platform_data *pdata = dev_get_platdata(dev); + struct spi_gpio *spi_gpio = spi_master_get_devdata(master); + int i; - ret = of_property_read_u32(np, "num-chipselects", &tmp); - if (ret < 0) { - dev_err(&pdev->dev, "num-chipselects property not found\n"); - goto error_free; - } +#ifdef GENERIC_BITBANG + if (!pdata || !pdata->num_chipselect) + return -ENODEV; +#endif + /* + * The master needs to think there is a chipselect even if not + * connected + */ + master->num_chipselect = pdata->num_chipselect ?: 1; - pdata->num_chipselect = tmp; - pdev->dev.platform_data = pdata; + spi_gpio->cs_gpios = devm_kcalloc(dev, master->num_chipselect, + sizeof(*spi_gpio->cs_gpios), + GFP_KERNEL); + if (!spi_gpio->cs_gpios) + return -ENOMEM; - return 1; + for (i = 0; i < master->num_chipselect; i++) { + spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", i, + GPIOD_OUT_HIGH); + if (IS_ERR(spi_gpio->cs_gpios[i])) + return PTR_ERR(spi_gpio->cs_gpios[i]); + } -error_free: - devm_kfree(&pdev->dev, pdata); - return ret; + return 0; } -#else -static inline int spi_gpio_probe_dt(struct platform_device *pdev) + +static void spi_gpio_put(void *data) { - return 0; + spi_master_put(data); } -#endif static int spi_gpio_probe(struct platform_device *pdev) { int status; struct spi_master *master; struct spi_gpio *spi_gpio; - struct spi_gpio_platform_data *pdata; - u16 master_flags = 0; - bool use_of = 0; + struct device *dev = &pdev->dev; + struct spi_bitbang *bb; + const struct of_device_id *of_id; - status = spi_gpio_probe_dt(pdev); - if (status < 0) - return status; - if (status > 0) - use_of = 1; - - pdata = dev_get_platdata(&pdev->dev); -#ifdef GENERIC_BITBANG - if (!pdata || (!use_of && !pdata->num_chipselect)) - return -ENODEV; -#endif + of_id = of_match_device(spi_gpio_dt_ids, &pdev->dev); - master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio)); + master = spi_alloc_master(dev, sizeof(*spi_gpio)); if (!master) return -ENOMEM; - spi_gpio = spi_master_get_devdata(master); - - spi_gpio->cs_gpios = devm_kcalloc(&pdev->dev, - pdata->num_chipselect, - sizeof(*spi_gpio->cs_gpios), - GFP_KERNEL); - if (!spi_gpio->cs_gpios) - return -ENOMEM; + status = devm_add_action_or_reset(&pdev->dev, spi_gpio_put, master); + if (status) + return status; - platform_set_drvdata(pdev, spi_gpio); + if (of_id) + status = spi_gpio_probe_dt(pdev, master); + else + status = spi_gpio_probe_pdata(pdev, master); - /* Determine if we have chip selects connected */ - spi_gpio->has_cs = !!pdata->num_chipselect; + if (status) + return status; - spi_gpio->pdev = pdev; - if (pdata) - spi_gpio->pdata = *pdata; + spi_gpio = spi_master_get_devdata(master); - status = spi_gpio_request(&pdev->dev, spi_gpio, - pdata->num_chipselect, &master_flags); + status = spi_gpio_request(dev, spi_gpio); if (status) return status; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); master->mode_bits = SPI_3WIRE | SPI_3WIRE_HIZ | SPI_CPHA | SPI_CPOL | SPI_CS_HIGH; - master->flags = master_flags; + if (!spi_gpio->mosi) { + /* HW configuration without MOSI pin + * + * No setting SPI_MASTER_NO_RX here - if there is only + * a MOSI pin connected the host can still do RX by + * changing the direction of the line. + */ + master->flags = SPI_MASTER_NO_TX; + } + master->bus_num = pdev->id; - /* The master needs to think there is a chipselect even if not connected */ - master->num_chipselect = spi_gpio->has_cs ? pdata->num_chipselect : 1; master->setup = spi_gpio_setup; master->cleanup = spi_gpio_cleanup; -#ifdef CONFIG_OF - master->dev.of_node = pdev->dev.of_node; -#endif - spi_gpio->bitbang.master = master; - spi_gpio->bitbang.chipselect = spi_gpio_chipselect; - spi_gpio->bitbang.set_line_direction = spi_gpio_set_direction; + bb = &spi_gpio->bitbang; + bb->master = master; + bb->chipselect = spi_gpio_chipselect; + bb->set_line_direction = spi_gpio_set_direction; - if ((master_flags & SPI_MASTER_NO_TX) == 0) { - spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0; - spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1; - spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2; - spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3; + if (master->flags & SPI_MASTER_NO_TX) { + bb->txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0; + bb->txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1; + bb->txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2; + bb->txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3; } else { - spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0; - spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1; - spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2; - spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3; + bb->txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0; + bb->txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1; + bb->txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2; + bb->txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3; } - spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer; + bb->setup_transfer = spi_bitbang_setup_transfer; - status = spi_bitbang_start(&spi_gpio->bitbang); + status = spi_bitbang_init(&spi_gpio->bitbang); if (status) - spi_master_put(master); - - return status; -} - -static int spi_gpio_remove(struct platform_device *pdev) -{ - struct spi_gpio *spi_gpio; - - spi_gpio = platform_get_drvdata(pdev); - - /* stop() unregisters child devices too */ - spi_bitbang_stop(&spi_gpio->bitbang); - - spi_master_put(spi_gpio->bitbang.master); + return status; - return 0; + return devm_spi_register_master(&pdev->dev, spi_master_get(master)); } MODULE_ALIAS("platform:" DRIVER_NAME); @@ -486,7 +450,6 @@ static struct platform_driver spi_gpio_driver = { .of_match_table = of_match_ptr(spi_gpio_dt_ids), }, .probe = spi_gpio_probe, - .remove = spi_gpio_remove, }; module_platform_driver(spi_gpio_driver); |