From mboxrd@z Thu Jan 1 00:00:00 1970 From: cezary.gapinski@gmail.com Subject: [PATCH v2 09/14] spi: stm32: split transfer one setup function Date: Mon, 24 Dec 2018 23:00:35 +0100 Message-ID: <1545688840-23992-10-git-send-email-cezary.gapinski@gmail.com> References: <1545688840-23992-1-git-send-email-cezary.gapinski@gmail.com> Cc: Maxime Coquelin , Alexandre Torgue , Mark Rutland , Cezary Gapinski To: Mark Brown , linux-spi@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Rob Herring , devicetree@vger.kernel.org, Amelie Delaunay Return-path: In-Reply-To: <1545688840-23992-1-git-send-email-cezary.gapinski@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org From: Cezary Gapinski Split stm32_spi_transfer_one_setup function into smaller chunks to be more generic for other stm32 SPI family drivers. Signed-off-by: Cezary Gapinski --- drivers/spi/spi-stm32.c | 270 ++++++++++++++++++++++++++++++++++-------------- 1 file changed, 192 insertions(+), 78 deletions(-) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 9cb7d33..bc8513f 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -101,11 +101,18 @@ #define STM32H7_SPI_MBR_DIV_MIN (2 << STM32H7_SPI_CFG1_MBR_MIN) #define STM32H7_SPI_MBR_DIV_MAX (2 << STM32H7_SPI_CFG1_MBR_MAX) -/* SPI Communication mode */ +/* STM32H7 SPI Communication mode */ +#define STM32H7_SPI_FULL_DUPLEX 0 +#define STM32H7_SPI_SIMPLEX_TX 1 +#define STM32H7_SPI_SIMPLEX_RX 2 +#define STM32H7_SPI_HALF_DUPLEX 3 + +/* SPI Communication type */ #define SPI_FULL_DUPLEX 0 #define SPI_SIMPLEX_TX 1 #define SPI_SIMPLEX_RX 2 -#define SPI_HALF_DUPLEX 3 +#define SPI_3WIRE_TX 3 +#define SPI_3WIRE_RX 4 #define SPI_1HZ_NS 1000000000 @@ -232,13 +239,16 @@ static int stm32_spi_get_bpw_mask(struct stm32_spi *spi) } /** - * stm32_spi_prepare_mbr - Determine SPI_CFG1.MBR value + * stm32_spi_prepare_mbr - Determine baud rate divisor value * @spi: pointer to the spi controller data structure * @speed_hz: requested speed + * @min_div: minimum baud rate divisor + * @max_div: maximum baud rate divisor * - * Return SPI_CFG1.MBR value in case of success or -EINVAL + * Return baud rate divisor value in case of success or -EINVAL */ -static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz) +static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz, + u32 min_div, u32 max_div) { u32 div, mbrdiv; @@ -251,8 +261,7 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz) * no need to check it there. * However, we need to ensure the following calculations. */ - if (div < STM32H7_SPI_MBR_DIV_MIN || - div > STM32H7_SPI_MBR_DIV_MAX) + if ((div < min_div) || (div > max_div)) return -EINVAL; /* Determine the first power of 2 greater than or equal to div */ @@ -802,7 +811,8 @@ static int stm32_spi_transfer_one_dma(struct stm32_spi *spi, } if (tx_dma_desc) { - if (spi->cur_comm == SPI_SIMPLEX_TX) { + if (spi->cur_comm == SPI_SIMPLEX_TX || + spi->cur_comm == SPI_3WIRE_TX) { tx_dma_desc->callback = stm32_spi_dma_cb; tx_dma_desc->callback_param = spi; } @@ -848,92 +858,130 @@ static int stm32_spi_transfer_one_dma(struct stm32_spi *spi, } /** - * stm32_spi_transfer_one_setup - common setup to transfer a single - * spi_transfer either using DMA or - * interrupts. + * stm32_spi_set_bpw - configure bits per word + * @spi: pointer to the spi controller data structure */ -static int stm32_spi_transfer_one_setup(struct stm32_spi *spi, - struct spi_device *spi_dev, - struct spi_transfer *transfer) +static void stm32_spi_set_bpw(struct stm32_spi *spi) { - unsigned long flags; - u32 cfg1_clrb = 0, cfg1_setb = 0, cfg2_clrb = 0, cfg2_setb = 0; - u32 mode, nb_words; - int ret = 0; + u32 bpw, fthlv; + u32 cfg1_clrb = 0, cfg1_setb = 0; - spin_lock_irqsave(&spi->lock, flags); + bpw = spi->cur_bpw - 1; - if (spi->cur_bpw != transfer->bits_per_word) { - u32 bpw, fthlv; - - spi->cur_bpw = transfer->bits_per_word; - bpw = spi->cur_bpw - 1; + cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE; + cfg1_setb |= (bpw << STM32H7_SPI_CFG1_DSIZE_SHIFT) & + STM32H7_SPI_CFG1_DSIZE; - cfg1_clrb |= STM32H7_SPI_CFG1_DSIZE; - cfg1_setb |= (bpw << STM32H7_SPI_CFG1_DSIZE_SHIFT) & - STM32H7_SPI_CFG1_DSIZE; + spi->cur_fthlv = stm32_spi_prepare_fthlv(spi); + fthlv = spi->cur_fthlv - 1; - spi->cur_fthlv = stm32_spi_prepare_fthlv(spi); - fthlv = spi->cur_fthlv - 1; + cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV; + cfg1_setb |= (fthlv << STM32H7_SPI_CFG1_FTHLV_SHIFT) & + STM32H7_SPI_CFG1_FTHLV; - cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV; - cfg1_setb |= (fthlv << STM32H7_SPI_CFG1_FTHLV_SHIFT) & - STM32H7_SPI_CFG1_FTHLV; - } - - if (spi->cur_speed != transfer->speed_hz) { - int mbr; + writel_relaxed( + (readl_relaxed(spi->base + STM32H7_SPI_CFG1) & + ~cfg1_clrb) | cfg1_setb, + spi->base + STM32H7_SPI_CFG1); +} - /* Update spi->cur_speed with real clock speed */ - mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz); - if (mbr < 0) { - ret = mbr; - goto out; - } +/** + * stm32_spi_set_mbr - Configure baud rate divisor in master mode + * @spi: pointer to the spi controller data structure + * @mbrdiv: baud rate divisor value + */ +static void stm32_spi_set_mbr(struct stm32_spi *spi, u32 mbrdiv) +{ + u32 cfg1_clrb = 0, cfg1_setb = 0; - transfer->speed_hz = spi->cur_speed; + cfg1_clrb |= STM32H7_SPI_CFG1_MBR; + cfg1_setb |= ((u32)mbrdiv << STM32H7_SPI_CFG1_MBR_SHIFT) & + STM32H7_SPI_CFG1_MBR; - cfg1_clrb |= STM32H7_SPI_CFG1_MBR; - cfg1_setb |= ((u32)mbr << STM32H7_SPI_CFG1_MBR_SHIFT) & - STM32H7_SPI_CFG1_MBR; - } + writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG1) & + ~cfg1_clrb) | cfg1_setb, + spi->base + STM32H7_SPI_CFG1); +} - if (cfg1_clrb || cfg1_setb) - writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG1) & - ~cfg1_clrb) | cfg1_setb, - spi->base + STM32H7_SPI_CFG1); +/** + * stm32_spi_communication_type - return transfer communication type + * @spi_dev: pointer to the spi device + * transfer: pointer to spi transfer + */ +static unsigned int stm32_spi_communication_type(struct spi_device *spi_dev, + struct spi_transfer *transfer) +{ + unsigned int type = SPI_FULL_DUPLEX; - mode = SPI_FULL_DUPLEX; if (spi_dev->mode & SPI_3WIRE) { /* MISO/MOSI signals shared */ /* * SPI_3WIRE and xfer->tx_buf != NULL and xfer->rx_buf != NULL - * is forbidden und unvalidated by SPI subsystem so depending + * is forbidden and unvalidated by SPI subsystem so depending * on the valid buffer, we can determine the direction of the * transfer. */ - mode = SPI_HALF_DUPLEX; if (!transfer->tx_buf) - stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, - STM32H7_SPI_CR1_HDDIR); - else if (!transfer->rx_buf) - stm32_spi_set_bits(spi, STM32H7_SPI_CR1, - STM32H7_SPI_CR1_HDDIR); + type = SPI_3WIRE_RX; + else + type = SPI_3WIRE_TX; } else { if (!transfer->tx_buf) - mode = SPI_SIMPLEX_RX; + type = SPI_SIMPLEX_RX; else if (!transfer->rx_buf) - mode = SPI_SIMPLEX_TX; + type = SPI_SIMPLEX_TX; } - if (spi->cur_comm != mode) { - spi->cur_comm = mode; - cfg2_clrb |= STM32H7_SPI_CFG2_COMM; - cfg2_setb |= (mode << STM32H7_SPI_CFG2_COMM_SHIFT) & - STM32H7_SPI_CFG2_COMM; + return type; +} + +/** + * stm32_spi_set_mode - configure communication mode + * @spi: pointer to the spi controller data structure + * @comm_type: type of communication to configure + */ +static int stm32_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type) +{ + u32 mode; + u32 cfg2_clrb = 0, cfg2_setb = 0; + + if (comm_type == SPI_3WIRE_RX) { + mode = STM32H7_SPI_HALF_DUPLEX; + stm32_spi_clr_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR); + } else if (comm_type == SPI_3WIRE_TX) { + mode = STM32H7_SPI_HALF_DUPLEX; + stm32_spi_set_bits(spi, STM32H7_SPI_CR1, STM32H7_SPI_CR1_HDDIR); + } else if (comm_type == SPI_SIMPLEX_RX) { + mode = STM32H7_SPI_SIMPLEX_RX; + } else if (comm_type == SPI_SIMPLEX_TX) { + mode = STM32H7_SPI_SIMPLEX_TX; + } else { + mode = STM32H7_SPI_FULL_DUPLEX; } + cfg2_clrb |= STM32H7_SPI_CFG2_COMM; + cfg2_setb |= (mode << STM32H7_SPI_CFG2_COMM_SHIFT) & + STM32H7_SPI_CFG2_COMM; + + writel_relaxed( + (readl_relaxed(spi->base + STM32H7_SPI_CFG2) & + ~cfg2_clrb) | cfg2_setb, + spi->base + STM32H7_SPI_CFG2); + + return 0; +} + +/** + * stm32_spi_data_idleness - configure minimum time delay inserted between two + * consecutive data frames in master mode + * @spi: pointer to the spi controller data structure + * @len: transfer len + */ +static void stm32_spi_data_idleness(struct stm32_spi *spi, u32 len) +{ + u32 cfg2_clrb = 0, cfg2_setb = 0; + cfg2_clrb |= STM32H7_SPI_CFG2_MIDI; - if ((transfer->len > 1) && (spi->cur_midi > 0)) { + if ((len > 1) && (spi->cur_midi > 0)) { u32 sck_period_ns = DIV_ROUND_UP(SPI_1HZ_NS, spi->cur_speed); u32 midi = min((u32)DIV_ROUND_UP(spi->cur_midi, sck_period_ns), (u32)STM32H7_SPI_CFG2_MIDI >> @@ -941,15 +989,85 @@ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi, dev_dbg(spi->dev, "period=%dns, midi=%d(=%dns)\n", sck_period_ns, midi, midi * sck_period_ns); - cfg2_setb |= (midi << STM32H7_SPI_CFG2_MIDI_SHIFT) & STM32H7_SPI_CFG2_MIDI; } - if (cfg2_clrb || cfg2_setb) - writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) & - ~cfg2_clrb) | cfg2_setb, - spi->base + STM32H7_SPI_CFG2); + writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CFG2) & + ~cfg2_clrb) | cfg2_setb, + spi->base + STM32H7_SPI_CFG2); +} + +/** + * stm32_spi_number_of_data - configure number of data at current transfer + * @spi: pointer to the spi controller data structure + * @len: transfer length + */ +static int stm32_spi_number_of_data(struct stm32_spi *spi, u32 nb_words) +{ + u32 cr2_clrb = 0, cr2_setb = 0; + + if (nb_words <= (STM32H7_SPI_CR2_TSIZE >> + STM32H7_SPI_CR2_TSIZE_SHIFT)) { + cr2_clrb |= STM32H7_SPI_CR2_TSIZE; + cr2_setb = nb_words << STM32H7_SPI_CR2_TSIZE_SHIFT; + writel_relaxed((readl_relaxed(spi->base + STM32H7_SPI_CR2) & + ~cr2_clrb) | cr2_setb, + spi->base + STM32H7_SPI_CR2); + } else { + return -EMSGSIZE; + } + + return 0; +} + +/** + * stm32_spi_transfer_one_setup - common setup to transfer a single + * spi_transfer either using DMA or + * interrupts. + */ +static int stm32_spi_transfer_one_setup(struct stm32_spi *spi, + struct spi_device *spi_dev, + struct spi_transfer *transfer) +{ + unsigned long flags; + unsigned int comm_type; + int nb_words, ret = 0; + + spin_lock_irqsave(&spi->lock, flags); + + if (spi->cur_bpw != transfer->bits_per_word) { + spi->cur_bpw = transfer->bits_per_word; + stm32_spi_set_bpw(spi); + } + + if (spi->cur_speed != transfer->speed_hz) { + int mbr; + + /* Update spi->cur_speed with real clock speed */ + mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz, + STM32H7_SPI_MBR_DIV_MIN, + STM32H7_SPI_MBR_DIV_MAX); + if (mbr < 0) { + ret = mbr; + goto out; + } + + transfer->speed_hz = spi->cur_speed; + stm32_spi_set_mbr(spi, mbr); + } + + comm_type = stm32_spi_communication_type(spi_dev, transfer); + if (spi->cur_comm != comm_type) { + stm32_spi_set_mode(spi, comm_type); + + if (ret < 0) + goto out; + + spi->cur_comm = comm_type; + } + + stm32_spi_data_idleness(spi, transfer->len); if (spi->cur_bpw <= 8) nb_words = transfer->len; @@ -957,14 +1075,10 @@ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi, nb_words = DIV_ROUND_UP(transfer->len * 8, 16); else nb_words = DIV_ROUND_UP(transfer->len * 8, 32); - nb_words <<= STM32H7_SPI_CR2_TSIZE_SHIFT; - if (nb_words <= STM32H7_SPI_CR2_TSIZE) { - writel_relaxed(nb_words, spi->base + STM32H7_SPI_CR2); - } else { - ret = -EMSGSIZE; + ret = stm32_spi_number_of_data(spi, nb_words); + if (ret < 0) goto out; - } spi->cur_xferlen = transfer->len; -- 2.7.4