From 0eb707ac7dd7a4329d93d47feada6c9bb5ea8ee9 Mon Sep 17 00:00:00 2001 From: Neil Armstrong Date: Thu, 12 Mar 2020 14:31:29 +0100 Subject: spi: meson-spicc: adapt burst handling for G12A support The G12A SPICC controller variant has a different FIFO size and doesn't handle the RX Half interrupt the same way as GXL & AXG variants. Thus simplify the burst management and take in account a variable FIFO size. Signed-off-by: Neil Armstrong Link: https://lore.kernel.org/r/20200312133131.26430-8-narmstrong@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi-meson-spicc.c | 129 ++++++++++++++++-------------------------- 1 file changed, 50 insertions(+), 79 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c index 4494a791f4a7..351ccd8dd2c2 100644 --- a/drivers/spi/spi-meson-spicc.c +++ b/drivers/spi/spi-meson-spicc.c @@ -141,12 +141,10 @@ #define writel_bits_relaxed(mask, val, addr) \ writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr) -#define SPICC_BURST_MAX 16 -#define SPICC_FIFO_HALF 10 - struct meson_spicc_data { unsigned int max_speed_hz; unsigned int min_speed_hz; + unsigned int fifo_size; bool has_oen; bool has_enhance_clk_div; }; @@ -166,8 +164,6 @@ struct meson_spicc_device { unsigned long tx_remain; unsigned long rx_remain; unsigned long xfer_remain; - bool is_burst_end; - bool is_last_burst; }; static void meson_spicc_oen_enable(struct meson_spicc_device *spicc) @@ -191,7 +187,7 @@ static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc) static inline bool meson_spicc_rxready(struct meson_spicc_device *spicc) { - return FIELD_GET(SPICC_RH | SPICC_RR | SPICC_RF_EN, + return FIELD_GET(SPICC_RH | SPICC_RR | SPICC_RF, readl_relaxed(spicc->base + SPICC_STATREG)); } @@ -246,34 +242,22 @@ static inline void meson_spicc_tx(struct meson_spicc_device *spicc) spicc->base + SPICC_TXDATA); } -static inline u32 meson_spicc_setup_rx_irq(struct meson_spicc_device *spicc, - u32 irq_ctrl) +static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc) { - if (spicc->rx_remain > SPICC_FIFO_HALF) - irq_ctrl |= SPICC_RH_EN; - else - irq_ctrl |= SPICC_RR_EN; - - return irq_ctrl; -} -static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc, - unsigned int burst_len) -{ + unsigned int burst_len = min_t(unsigned int, + spicc->xfer_remain / + spicc->bytes_per_word, + spicc->data->fifo_size); /* Setup Xfer variables */ spicc->tx_remain = burst_len; spicc->rx_remain = burst_len; spicc->xfer_remain -= burst_len * spicc->bytes_per_word; - spicc->is_burst_end = false; - if (burst_len < SPICC_BURST_MAX || !spicc->xfer_remain) - spicc->is_last_burst = true; - else - spicc->is_last_burst = false; /* Setup burst length */ writel_bits_relaxed(SPICC_BURSTLENGTH_MASK, FIELD_PREP(SPICC_BURSTLENGTH_MASK, - burst_len), + burst_len - 1), spicc->base + SPICC_CONREG); /* Fill TX FIFO */ @@ -283,61 +267,26 @@ static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc, static irqreturn_t meson_spicc_irq(int irq, void *data) { struct meson_spicc_device *spicc = (void *) data; - u32 ctrl = readl_relaxed(spicc->base + SPICC_INTREG); - u32 stat = readl_relaxed(spicc->base + SPICC_STATREG) & ctrl; - ctrl &= ~(SPICC_RH_EN | SPICC_RR_EN); + writel_bits_relaxed(SPICC_TC, SPICC_TC, spicc->base + SPICC_STATREG); /* Empty RX FIFO */ meson_spicc_rx(spicc); - /* Enable TC interrupt since we transferred everything */ - if (!spicc->tx_remain && !spicc->rx_remain) { - spicc->is_burst_end = true; - - /* Enable TC interrupt */ - ctrl |= SPICC_TC_EN; - - /* Reload IRQ status */ - stat = readl_relaxed(spicc->base + SPICC_STATREG) & ctrl; - } - - /* Check transfer complete */ - if ((stat & SPICC_TC) && spicc->is_burst_end) { - unsigned int burst_len; - - /* Clear TC bit */ - writel_relaxed(SPICC_TC, spicc->base + SPICC_STATREG); - - /* Disable TC interrupt */ - ctrl &= ~SPICC_TC_EN; - - if (spicc->is_last_burst) { - /* Disable all IRQs */ - writel(0, spicc->base + SPICC_INTREG); - - spi_finalize_current_transfer(spicc->master); + if (!spicc->xfer_remain) { + /* Disable all IRQs */ + writel(0, spicc->base + SPICC_INTREG); - return IRQ_HANDLED; - } + spi_finalize_current_transfer(spicc->master); - burst_len = min_t(unsigned int, - spicc->xfer_remain / spicc->bytes_per_word, - SPICC_BURST_MAX); - - /* Setup burst */ - meson_spicc_setup_burst(spicc, burst_len); - - /* Restart burst */ - writel_bits_relaxed(SPICC_XCH, SPICC_XCH, - spicc->base + SPICC_CONREG); + return IRQ_HANDLED; } - /* Setup RX interrupt trigger */ - ctrl = meson_spicc_setup_rx_irq(spicc, ctrl); + /* Setup burst */ + meson_spicc_setup_burst(spicc); - /* Reconfigure interrupts */ - writel(ctrl, spicc->base + SPICC_INTREG); + /* Start burst */ + writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG); return IRQ_HANDLED; } @@ -405,6 +354,28 @@ static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc, clk_set_rate(spicc->clk, xfer->speed_hz); meson_spicc_auto_io_delay(spicc); + + writel_relaxed(0, spicc->base + SPICC_DMAREG); +} + +static void meson_spicc_reset_fifo(struct meson_spicc_device *spicc) +{ + u32 data; + + if (spicc->data->has_oen) + writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO, + SPICC_ENH_MAIN_CLK_AO, + spicc->base + SPICC_ENH_CTL0); + + writel_bits_relaxed(SPICC_FIFORST_W1_MASK, SPICC_FIFORST_W1_MASK, + spicc->base + SPICC_TESTREG); + + while (meson_spicc_rxready(spicc)) + data = readl_relaxed(spicc->base + SPICC_RXDATA); + + if (spicc->data->has_oen) + writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO, 0, + spicc->base + SPICC_ENH_CTL0); } static int meson_spicc_transfer_one(struct spi_master *master, @@ -412,8 +383,6 @@ static int meson_spicc_transfer_one(struct spi_master *master, struct spi_transfer *xfer) { struct meson_spicc_device *spicc = spi_master_get_devdata(master); - unsigned int burst_len; - u32 irq = 0; /* Store current transfer */ spicc->xfer = xfer; @@ -427,22 +396,22 @@ static int meson_spicc_transfer_one(struct spi_master *master, spicc->bytes_per_word = DIV_ROUND_UP(spicc->xfer->bits_per_word, 8); + if (xfer->len % spicc->bytes_per_word) + return -EINVAL; + /* Setup transfer parameters */ meson_spicc_setup_xfer(spicc, xfer); - burst_len = min_t(unsigned int, - spicc->xfer_remain / spicc->bytes_per_word, - SPICC_BURST_MAX); - - meson_spicc_setup_burst(spicc, burst_len); + meson_spicc_reset_fifo(spicc); - irq = meson_spicc_setup_rx_irq(spicc, irq); + /* Setup burst */ + meson_spicc_setup_burst(spicc); /* Start burst */ writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG); /* Enable interrupts */ - writel_relaxed(irq, spicc->base + SPICC_INTREG); + writel_relaxed(SPICC_TC_EN, spicc->base + SPICC_INTREG); return 1; } @@ -499,7 +468,7 @@ static int meson_spicc_prepare_message(struct spi_master *master, /* Setup no wait cycles by default */ writel_relaxed(0, spicc->base + SPICC_PERIODREG); - writel_bits_relaxed(BIT(24), BIT(24), spicc->base + SPICC_TESTREG); + writel_bits_relaxed(SPICC_LBC_W1, 0, spicc->base + SPICC_TESTREG); return 0; } @@ -797,11 +766,13 @@ static int meson_spicc_remove(struct platform_device *pdev) static const struct meson_spicc_data meson_spicc_gx_data = { .max_speed_hz = 30000000, .min_speed_hz = 325000, + .fifo_size = 16, }; static const struct meson_spicc_data meson_spicc_axg_data = { .max_speed_hz = 80000000, .min_speed_hz = 325000, + .fifo_size = 16, .has_oen = true, .has_enhance_clk_div = true, }; -- cgit