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Wed, 19 Apr 2023 15:27:55 +0900 (KST) Received: from epsmtrp2.samsung.com (unknown [182.195.40.14]) by epcas2p4.samsung.com (KnoxPortal) with ESMTPA id 20230419062755epcas2p43a1127f4bb28cf1cf3f42e5d3cc597cd~XQhxblEQF1700617006epcas2p48; Wed, 19 Apr 2023 06:27:55 +0000 (GMT) Received: from epsmgms1p1new.samsung.com (unknown [182.195.42.41]) by epsmtrp2.samsung.com (KnoxPortal) with ESMTP id 20230419062755epsmtrp2fa7d8d50512cb513ff544bfc27a74370~XQhxa3Sqr0106901069epsmtrp2S; Wed, 19 Apr 2023 06:27:55 +0000 (GMT) X-AuditID: b6c32a45-bb5ff700000026e9-55-643f89eb8831 Received: from epsmtip2.samsung.com ( [182.195.34.31]) by epsmgms1p1new.samsung.com (Symantec Messaging Gateway) with SMTP id DC.65.08279.BE98F346; Wed, 19 Apr 2023 15:27:55 +0900 (KST) Received: from localhost.localdomain (unknown [10.229.9.55]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20230419062755epsmtip2f767e554dd57b52e647e502fe222dc6b~XQhxPTaia0394003940epsmtip2X; Wed, 19 Apr 2023 06:27:55 +0000 (GMT) From: Jaewon Kim To: Mark Brown , Krzysztof Kozlowski , Andi Shyti , Alim Akhtar Cc: linux-spi@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Chanho Park , Jaewon Kim Subject: [PATCH v2 4/4] spi: s3c64xx: support interrupt based pio mode Date: Wed, 19 Apr 2023 15:06:39 +0900 Message-Id: <20230419060639.38853-5-jaewon02.kim@samsung.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230419060639.38853-1-jaewon02.kim@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrPKsWRmVeSWpSXmKPExsWy7bCmme7rTvsUgx9HLCwezNvGZrH4x3Mm i6kPn7BZXN6vbbGj4Qirxd7XW9ktNj2+xmpxedccNosZ5/cxWTR+vMnuwOVxfcknZo9NqzrZ PO5c28PmsXlJvUffllWMHp83yQWwRWXbZKQmpqQWKaTmJeenZOal2yp5B8c7x5uaGRjqGlpa mCsp5CXmptoqufgE6Lpl5gAdpqRQlphTChQKSCwuVtK3synKLy1JVcjILy6xVUotSMkpMC/Q K07MLS7NS9fLSy2xMjQwMDIFKkzIzri8fQF7QZN2xYfLM5gaGJ8rdjFyckgImEgsudzD3sXI xSEksINRYs7hXywQzidGiYN7/jOCVAkJfGOUWLvaD6bj8stWJoiivYwSew49hXI+Mkq8fg/i cHKwCWhLfF+/mBUkISKwmFFi798vzCAOs8ANRonuN5tZQKqEBdwk+t7NYgexWQRUJfa/2cgG YvMK2EocfDmHFWKfvMTqDQeYQWxOATuJhZ+usYEMkhB4xC6xbN1fRogiF4lLp9uYIGxhiVfH t7BD2FISn9/tZYOwsyXap/+BGlohcXHDbKi4scSsZ+1AcziArtOUWL9LH8SUEFCWOHIL7Exm AT6JjsN/2SHCvBIdbUIQjWoS96eegxoiIzHpyEqoAzwklm/9ygwJlImMEq0rZjBPYJSbhbBg ASPjKkax1ILi3PTUYqMCQ3iUJefnbmIEpzwt1x2Mk99+0DvEyMTBeIhRgoNZSYT3jKtVihBv SmJlVWpRfnxRaU5q8SFGU2DYTWSWEk3OBybdvJJ4QxNLAxMzM0NzI1MDcyVxXmnbk8lCAumJ JanZqakFqUUwfUwcnFINTDKhJsb6331TNkZudrLgZjhStHmzQIjQhlcr3fPE3KwcS3jFZP9f lha/PDtCydBqItvxVGbVXSvTJDKzxfO4vxyWCPQIiVE7ano2ZdfPLSeeZOxuEVj9ONbDeEbp zaTadlWPaSIaP+263kQeOpaVqd9y52izdNPxmpo5xiWrg1/7sHSz+nad0zE8NM91/r+7Pbf6 rfzs33BwKfisN7Hybdm6cN7urKpvzzR3Wvw0vO9d6zIz9KLO772dIR0O1y+enyAsLbiASbVJ o3vK1RPXq2vnzd+/rDJx9e4z/Cznl7/xrr4f3x9l4+zypJr/kdKBqqoN0sFbnRPPyAcUL9S3 6BBpq2HQOH5Ov9zcJ1GJpTgj0VCLuag4EQCnsoYoAgQAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrFLMWRmVeSWpSXmKPExsWy7bCSvO7rTvsUg32rhCwezNvGZrH4x3Mm i6kPn7BZXN6vbbGj4Qirxd7XW9ktNj2+xmpxedccNosZ5/cxWTR+vMnuwOVxfcknZo9NqzrZ PO5c28PmsXlJvUffllWMHp83yQWwRXHZpKTmZJalFunbJXBlXN6+gL2gSbviw+UZTA2MzxW7 GDk5JARMJC6/bGXqYuTiEBLYzSjxcuUWJoiEjMTyZ31sELawxP2WI6wQRe8ZJd58uQBWxCag LfF9/WJWEFtEYCmjxM1uKZAiZoF7QJMmfQMrEhZwk+h7N4sdxGYRUJXY/2Yj2FReAVuJgy/n sEJskJdYveEAM4jNKWAnsfDTNbAaIaCa3fPesk9g5FvAyLCKUTK1oDg3PbfYsMAwL7Vcrzgx t7g0L10vOT93EyM4OLU0dzBuX/VB7xAjEwfjIUYJDmYlEd4zrlYpQrwpiZVVqUX58UWlOanF hxilOViUxHkvdJ2MFxJITyxJzU5NLUgtgskycXBKNTBJs9oE+My+4KvyTyzyrVBp8vP3B+1W Pitc+8o0/6ro9w8Fll/u7U78z2ZWcjeBc6a09Zl5epUv/vVHvdq/2+y38cc2sRWJLfnlBzxW Zgi4zfOo/V0qOH3xxgWPrxvzSHX5h7G05xlO/zf5VXVzaMvX1qt6TYXBTSXbH4T8r2IzfXCR Z5bZde/uSFG/9SFL0+r7Epa718p2HAhiDp7j9ijBo4NxzvE/S/sCPu59MSMyRXt6h5aYLq/h 55nmrXpq5olG8eoT/rYubnk4c3Ku+pd9/rel24Nuch98IHdESnHanznTNsX/NN57YmUyO1+/ wS4F64dp7xjqjsuUru0/+KPM2vtL4YmrDfFV/EvUdyixFGckGmoxFxUnAgDvFAnMvQIAAA== X-CMS-MailID: 20230419062755epcas2p43a1127f4bb28cf1cf3f42e5d3cc597cd X-Msg-Generator: CA X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20230419062755epcas2p43a1127f4bb28cf1cf3f42e5d3cc597cd References: <20230419060639.38853-1-jaewon02.kim@samsung.com> Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Interrupt based pio mode is supported to reduce CPU load. If transfer size is larger than 32 byte, it is processed using interrupt. Signed-off-by: Jaewon Kim --- drivers/spi/spi-s3c64xx.c | 82 ++++++++++++++++++++++++++++++++------- 1 file changed, 67 insertions(+), 15 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index cf3060b2639b..ce1afb9a4ed4 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -58,6 +58,8 @@ #define S3C64XX_SPI_MODE_BUS_TSZ_HALFWORD (1<<17) #define S3C64XX_SPI_MODE_BUS_TSZ_WORD (2<<17) #define S3C64XX_SPI_MODE_BUS_TSZ_MASK (3<<17) +#define S3C64XX_SPI_MODE_RX_RDY_LVL GENMASK(16, 11) +#define S3C64XX_SPI_MODE_RX_RDY_LVL_SHIFT 11 #define S3C64XX_SPI_MODE_SELF_LOOPBACK (1<<3) #define S3C64XX_SPI_MODE_RXDMA_ON (1<<2) #define S3C64XX_SPI_MODE_TXDMA_ON (1<<1) @@ -114,6 +116,8 @@ #define S3C64XX_SPI_TRAILCNT S3C64XX_SPI_MAX_TRAILCNT +#define S3C64XX_SPI_POLLING_SIZE 32 + #define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t) #define is_polling(x) (x->cntrlr_info->polling) @@ -552,10 +556,11 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd, } static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd, - struct spi_transfer *xfer) + struct spi_transfer *xfer, int use_irq) { void __iomem *regs = sdd->regs; unsigned long val; + unsigned long time; u32 status; int loops; u32 cpy_len; @@ -563,17 +568,24 @@ static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd, int ms; u32 tx_time; - /* sleep during signal transfer time */ - status = readl(regs + S3C64XX_SPI_STATUS); - if (RX_FIFO_LVL(status, sdd) < xfer->len) { - tx_time = (xfer->len * 8 * 1000 * 1000) / sdd->cur_speed; - usleep_range(tx_time / 2, tx_time); - } - /* millisecs to xfer 'len' bytes @ 'cur_speed' */ ms = xfer->len * 8 * 1000 / sdd->cur_speed; ms += 10; /* some tolerance */ + if (use_irq) { + val = msecs_to_jiffies(ms); + time = wait_for_completion_timeout(&sdd->xfer_completion, val); + if (!time) + return -EIO; + } else { + /* sleep during signal transfer time */ + status = readl(regs + S3C64XX_SPI_STATUS); + if (RX_FIFO_LVL(status, sdd) < xfer->len) { + tx_time = (xfer->len * 8 * 1000 * 1000) / sdd->cur_speed; + usleep_range(tx_time / 2, tx_time); + } + } + val = msecs_to_loops(ms); do { cpu_relax(); @@ -737,10 +749,13 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master, void *rx_buf = NULL; int target_len = 0, origin_len = 0; int use_dma = 0; + int use_irq = 0; int status; u32 speed; u8 bpw; unsigned long flags; + u32 rdy_lv; + u32 val; reinit_completion(&sdd->xfer_completion); @@ -761,17 +776,46 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master, sdd->rx_dma.ch && sdd->tx_dma.ch) { use_dma = 1; - } else if (xfer->len > fifo_len) { + } else if (xfer->len >= fifo_len) { tx_buf = xfer->tx_buf; rx_buf = xfer->rx_buf; origin_len = xfer->len; - target_len = xfer->len; - if (xfer->len > fifo_len) - xfer->len = fifo_len; + xfer->len = fifo_len - 1; } do { + /* transfer size is greater than 32, change to IRQ mode */ + if (xfer->len > S3C64XX_SPI_POLLING_SIZE) + use_irq = 1; + + if (use_irq) { + reinit_completion(&sdd->xfer_completion); + + rdy_lv = xfer->len; + /* Setup RDY_FIFO trigger Level + * RDY_LVL = + * fifo_lvl up to 64 byte -> N bytes + * 128 byte -> RDY_LVL * 2 bytes + * 256 byte -> RDY_LVL * 4 bytes + */ + if (fifo_len == 128) + rdy_lv /= 2; + else if (fifo_len == 256) + rdy_lv /= 4; + + val = readl(sdd->regs + S3C64XX_SPI_MODE_CFG); + val &= ~S3C64XX_SPI_MODE_RX_RDY_LVL; + val |= (rdy_lv << S3C64XX_SPI_MODE_RX_RDY_LVL_SHIFT); + writel(val, sdd->regs + S3C64XX_SPI_MODE_CFG); + + /* Enable FIFO_RDY_EN IRQ */ + val = readl(sdd->regs + S3C64XX_SPI_INT_EN); + writel((val | S3C64XX_SPI_INT_RX_FIFORDY_EN), + sdd->regs + S3C64XX_SPI_INT_EN); + + } + spin_lock_irqsave(&sdd->lock, flags); /* Pending only which is to be done */ @@ -793,7 +837,7 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master, if (use_dma) status = s3c64xx_wait_for_dma(sdd, xfer); else - status = s3c64xx_wait_for_pio(sdd, xfer); + status = s3c64xx_wait_for_pio(sdd, xfer, use_irq); if (status) { dev_err(&spi->dev, @@ -832,8 +876,8 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master, if (xfer->rx_buf) xfer->rx_buf += xfer->len; - if (target_len > fifo_len) - xfer->len = fifo_len; + if (target_len >= fifo_len) + xfer->len = fifo_len - 1; else xfer->len = target_len; } @@ -1003,6 +1047,14 @@ static irqreturn_t s3c64xx_spi_irq(int irq, void *data) dev_err(&spi->dev, "TX underrun\n"); } + if (val & S3C64XX_SPI_ST_RX_FIFORDY) { + complete(&sdd->xfer_completion); + /* No pending clear irq, turn-off INT_EN_RX_FIFO_RDY */ + val = readl(sdd->regs + S3C64XX_SPI_INT_EN); + writel((val & ~S3C64XX_SPI_INT_RX_FIFORDY_EN), + sdd->regs + S3C64XX_SPI_INT_EN); + } + /* Clear the pending irq by setting and then clearing it */ writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR); writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR);