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[31.10.206.125]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-42f771a1209sm23530685e9.0.2024.10.02.04.20.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Oct 2024 04:20:29 -0700 (PDT) From: Stefan Eichenberger To: o.rempel@pengutronix.de, kernel@pengutronix.de, andi.shyti@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, Frank.Li@nxp.com Cc: linux-i2c@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, francesco.dolcini@toradex.com, Stefan Eichenberger Subject: [PATCH v4 2/4] i2c: imx: separate atomic, dma and non-dma use case Date: Wed, 2 Oct 2024 13:19:40 +0200 Message-ID: <20241002112020.23913-3-eichest@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241002112020.23913-1-eichest@gmail.com> References: <20241002112020.23913-1-eichest@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Stefan Eichenberger Separate the atomic, dma and non-dma use case as a preparation step for moving the non-dma use case to the isr to avoid rescheduling while a transfer is in progress. Signed-off-by: Stefan Eichenberger Reviewed-by: Frank Li Acked-by: Oleksij Rempel --- drivers/i2c/busses/i2c-imx.c | 107 +++++++++++++++++++++++------------ 1 file changed, 70 insertions(+), 37 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index fbacdfaf6b28e..8e9cdeff278a8 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -1011,6 +1011,43 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *= i2c_imx, return i2c_imx_acked(i2c_imx); } =20 +static int i2c_imx_prepare_read(struct imx_i2c_struct *i2c_imx, + struct i2c_msg *msgs, bool atomic, + bool use_dma) +{ + int result; + unsigned int temp =3D 0; + + /* write slave address */ + imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); + result =3D i2c_imx_trx_complete(i2c_imx, atomic); + if (result) + return result; + result =3D i2c_imx_acked(i2c_imx); + if (result) + return result; + + dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__); + + /* setup bus to read data */ + temp =3D imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); + temp &=3D ~I2CR_MTX; + + /* + * Reset the I2CR_TXAK flag initially for SMBus block read since the + * length is unknown + */ + if (msgs->len - 1) + temp &=3D ~I2CR_TXAK; + if (use_dma) + temp |=3D I2CR_DMAEN; + + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); + imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ + + return 0; +} + static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg) { @@ -1021,6 +1058,11 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i= 2c_imx, struct imx_i2c_dma *dma =3D i2c_imx->dma; struct device *dev =3D &i2c_imx->adapter.dev; =20 + result =3D i2c_imx_prepare_read(i2c_imx, msgs, false, true); + if (result) + return result; + + dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__); =20 dma->chan_using =3D dma->chan_rx; dma->dma_transfer_dir =3D DMA_DEV_TO_MEM; @@ -1131,50 +1173,24 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c= _imx, struct i2c_msg *msgs, return 0; } =20 +static int i2c_imx_atomic_write(struct imx_i2c_struct *i2c_imx, struct i2c= _msg *msgs) +{ + return i2c_imx_write(i2c_imx, msgs, true); +} + static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *ms= gs, bool is_lastmsg, bool atomic) { int i, result; unsigned int temp; int block_data =3D msgs->flags & I2C_M_RECV_LEN; - int use_dma =3D i2c_imx->dma && msgs->flags & I2C_M_DMA_SAFE && - msgs->len >=3D DMA_THRESHOLD && !block_data; =20 - dev_dbg(&i2c_imx->adapter.dev, - "<%s> write slave address: addr=3D0x%x\n", - __func__, i2c_8bit_addr_from_msg(msgs)); - - /* write slave address */ - imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); - result =3D i2c_imx_trx_complete(i2c_imx, atomic); + result =3D i2c_imx_prepare_read(i2c_imx, msgs, atomic, false); if (result) return result; - result =3D i2c_imx_acked(i2c_imx); - if (result) - return result; - - dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__); - - /* setup bus to read data */ - temp =3D imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); - temp &=3D ~I2CR_MTX; - - /* - * Reset the I2CR_TXAK flag initially for SMBus block read since the - * length is unknown - */ - if ((msgs->len - 1) || block_data) - temp &=3D ~I2CR_TXAK; - if (use_dma) - temp |=3D I2CR_DMAEN; - imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); - imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ =20 dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__); =20 - if (use_dma) - return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg); - /* read data */ for (i =3D 0; i < msgs->len; i++) { u8 len =3D 0; @@ -1241,6 +1257,12 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_i= mx, struct i2c_msg *msgs, return 0; } =20 +static int i2c_imx_atomic_read(struct imx_i2c_struct *i2c_imx, struct i2c_= msg *msgs, + bool is_lastmsg) +{ + return i2c_imx_read(i2c_imx, msgs, is_lastmsg, true); +} + static int i2c_imx_xfer_common(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num, bool atomic) { @@ -1248,6 +1270,7 @@ static int i2c_imx_xfer_common(struct i2c_adapter *ad= apter, int result; bool is_lastmsg =3D false; struct imx_i2c_struct *i2c_imx =3D i2c_get_adapdata(adapter); + int use_dma =3D 0; =20 /* Start I2C transfer */ result =3D i2c_imx_start(i2c_imx, atomic); @@ -1300,15 +1323,25 @@ static int i2c_imx_xfer_common(struct i2c_adapter *= adapter, (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0), (temp & I2SR_RXAK ? 1 : 0)); #endif + + use_dma =3D i2c_imx->dma && msgs[i].len >=3D DMA_THRESHOLD && + msgs[i].flags & I2C_M_DMA_SAFE; if (msgs[i].flags & I2C_M_RD) { - result =3D i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, atomic); + int block_data =3D msgs->flags & I2C_M_RECV_LEN; + + if (atomic) + result =3D i2c_imx_atomic_read(i2c_imx, &msgs[i], is_lastmsg); + else if (use_dma && !block_data) + result =3D i2c_imx_dma_read(i2c_imx, &msgs[i], is_lastmsg); + else + result =3D i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, false); } else { - if (!atomic && - i2c_imx->dma && msgs[i].len >=3D DMA_THRESHOLD && - msgs[i].flags & I2C_M_DMA_SAFE) + if (atomic) + result =3D i2c_imx_atomic_write(i2c_imx, &msgs[i]); + else if (use_dma) result =3D i2c_imx_dma_write(i2c_imx, &msgs[i]); else - result =3D i2c_imx_write(i2c_imx, &msgs[i], atomic); + result =3D i2c_imx_write(i2c_imx, &msgs[i], false); } if (result) goto fail0; --=20 2.43.0