diff options
Diffstat (limited to 'drivers/spi/spi_gpio.c')
| -rw-r--r-- | drivers/spi/spi_gpio.c | 109 |
1 files changed, 87 insertions, 22 deletions
diff --git a/drivers/spi/spi_gpio.c b/drivers/spi/spi_gpio.c index 7edbd5807e0e..e24a63498acb 100644 --- a/drivers/spi/spi_gpio.c +++ b/drivers/spi/spi_gpio.c @@ -146,25 +146,63 @@ static inline int getmiso(const struct spi_device *spi) static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits) { - return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits); + return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); } static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits) { - return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits); + return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits); } static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits) { - return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits); + return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits); } static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits) { - return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits); + return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits); +} + +/* + * These functions do not call setmosi or getmiso if respective flag + * (SPI_MASTER_NO_RX or SPI_MASTER_NO_TX) is set, so they are safe to + * call when such pin is not present or defined in the controller. + * A separate set of callbacks is defined to get highest possible + * speed in the generic case (when both MISO and MOSI lines are + * available), as optimiser will remove the checks when argument is + * constant. + */ + +static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + unsigned flags = spi->master->flags; + return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); +} + +static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + unsigned flags = spi->master->flags; + return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); +} + +static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + unsigned flags = spi->master->flags; + return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); +} + +static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + unsigned flags = spi->master->flags; + return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); } /*----------------------------------------------------------------------*/ @@ -232,19 +270,30 @@ static int __init spi_gpio_alloc(unsigned pin, const char *label, bool is_in) } static int __init -spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label) +spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label, + u16 *res_flags) { int value; /* NOTE: SPI_*_GPIO symbols may reference "pdata" */ - value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false); - if (value) - goto done; + if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) { + value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false); + if (value) + goto done; + } else { + /* HW configuration without MOSI pin */ + *res_flags |= SPI_MASTER_NO_TX; + } - value = spi_gpio_alloc(SPI_MISO_GPIO, label, true); - if (value) - goto free_mosi; + if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) { + value = spi_gpio_alloc(SPI_MISO_GPIO, label, true); + if (value) + goto free_mosi; + } else { + /* HW configuration without MISO pin */ + *res_flags |= SPI_MASTER_NO_RX; + } value = spi_gpio_alloc(SPI_SCK_GPIO, label, false); if (value) @@ -253,9 +302,11 @@ spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label) goto done; free_miso: - gpio_free(SPI_MISO_GPIO); + if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) + gpio_free(SPI_MISO_GPIO); free_mosi: - gpio_free(SPI_MOSI_GPIO); + if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) + gpio_free(SPI_MOSI_GPIO); done: return value; } @@ -266,6 +317,7 @@ static int __init spi_gpio_probe(struct platform_device *pdev) struct spi_master *master; struct spi_gpio *spi_gpio; struct spi_gpio_platform_data *pdata; + u16 master_flags = 0; pdata = pdev->dev.platform_data; #ifdef GENERIC_BITBANG @@ -273,7 +325,7 @@ static int __init spi_gpio_probe(struct platform_device *pdev) return -ENODEV; #endif - status = spi_gpio_request(pdata, dev_name(&pdev->dev)); + status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags); if (status < 0) return status; @@ -289,6 +341,7 @@ static int __init spi_gpio_probe(struct platform_device *pdev) if (pdata) spi_gpio->pdata = *pdata; + master->flags = master_flags; master->bus_num = pdev->id; master->num_chipselect = SPI_N_CHIPSEL; master->setup = spi_gpio_setup; @@ -296,10 +349,18 @@ static int __init spi_gpio_probe(struct platform_device *pdev) spi_gpio->bitbang.master = spi_master_get(master); spi_gpio->bitbang.chipselect = spi_gpio_chipselect; - 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_RX | SPI_MASTER_NO_RX)) == 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; + } 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; + } spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer; spi_gpio->bitbang.flags = SPI_CS_HIGH; @@ -307,8 +368,10 @@ static int __init spi_gpio_probe(struct platform_device *pdev) if (status < 0) { spi_master_put(spi_gpio->bitbang.master); gpio_free: - gpio_free(SPI_MISO_GPIO); - gpio_free(SPI_MOSI_GPIO); + if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) + gpio_free(SPI_MISO_GPIO); + if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) + gpio_free(SPI_MOSI_GPIO); gpio_free(SPI_SCK_GPIO); spi_master_put(master); } @@ -331,8 +394,10 @@ static int __exit spi_gpio_remove(struct platform_device *pdev) platform_set_drvdata(pdev, NULL); - gpio_free(SPI_MISO_GPIO); - gpio_free(SPI_MOSI_GPIO); + if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) + gpio_free(SPI_MISO_GPIO); + if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) + gpio_free(SPI_MOSI_GPIO); gpio_free(SPI_SCK_GPIO); return status; |