Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752286AbdGaNba (ORCPT ); Mon, 31 Jul 2017 09:31:30 -0400 Received: from sauhun.de ([88.99.104.3]:49267 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751735AbdGaNb2 (ORCPT ); Mon, 31 Jul 2017 09:31:28 -0400 Date: Mon, 31 Jul 2017 15:31:24 +0200 From: Wolfram Sang To: thor.thayer@linux.intel.com Cc: robh+dt@kernel.org, mark.rutland@arm.com, davem@davemloft.net, gregkh@linuxfoundation.org, mchehab@kernel.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCHv5 3/3] i2c: altera: Add Altera I2C Controller driver Message-ID: <20170731133124.smwztpkul2qjy26p@ninjato> References: <1500309314-18464-1-git-send-email-thor.thayer@linux.intel.com> <1500309314-18464-4-git-send-email-thor.thayer@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="75tqzgfvrtlyo56b" Content-Disposition: inline In-Reply-To: <1500309314-18464-4-git-send-email-thor.thayer@linux.intel.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 21315 Lines: 675 --75tqzgfvrtlyo56b Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Thor, thanks for the patches! A few comments and questions from me. On Mon, Jul 17, 2017 at 11:35:14AM -0500, thor.thayer@linux.intel.com wrote: > From: Thor Thayer >=20 > Add driver support for the Altera I2C Controller. The I2C > controller is soft IP for use in FPGAs. >=20 > Signed-off-by: Thor Thayer > --- > v2 Remove altr, from fifo-size to agree with bindings. > Change compatible string to "altr,softip-i2c" > v3 Add version to compatible string "altr,softip-i2c-v1.0" > v4 Add default 100kHz message. Cleanup IRQ error message. > v5 Cleanup header usage - remove init.h. > Fix 1 byte RX bug and add convenience function for transfer shared by= RX and TX. > Use readl_poll_timeout_atomic() function. > Cache the I2C Interrupt Status Enable Register. > Cleanup of irq_mask by combining into 1 function. > Use i2c_8bit_addr_from_msg() for cleaner xfer_msg implementation. > Restructure altr_i2c_xfer() without arrays and indexes. > Remove redundant assignments. > Remove function calls from inside if() statements. > Convert of_property_read_u32() to device_property_read_u32(). > Call i2c_m_read() once in irq. > --- > drivers/i2c/busses/Kconfig | 10 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-altera.c | 510 ++++++++++++++++++++++++++++++++++= ++++++ > 3 files changed, 521 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-altera.c >=20 > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 1006b23..668147bf 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -328,6 +328,16 @@ config I2C_POWERMAC > =20 > comment "I2C system bus drivers (mostly embedded / system-on-chip)" > =20 > +config I2C_ALTERA > + tristate "Altera Soft IP I2C" > + depends on (ARCH_SOCFPGA || NIOS2) && OF > + help > + If you say yes to this option, support will be included for the > + Altera Soft IP I2C interfaces on SoCFPGA and Nios2 architectures. > + > + This driver can also be built as a module. If so, the module > + will be called i2c-altera. > + > config I2C_ASPEED > tristate "Aspeed I2C Controller" > depends on ARCH_ASPEED || COMPILE_TEST > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 1b2fc81..1395dcb 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_I2C_HYDRA) +=3D i2c-hydra.o > obj-$(CONFIG_I2C_POWERMAC) +=3D i2c-powermac.o > =20 > # Embedded system I2C/SMBus host controller drivers > +obj-$(CONFIG_I2C_ALTERA) +=3D i2c-altera.o > obj-$(CONFIG_I2C_ASPEED) +=3D i2c-aspeed.o > obj-$(CONFIG_I2C_AT91) +=3D i2c-at91.o > obj-$(CONFIG_I2C_AU1550) +=3D i2c-au1550.o > diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-alt= era.c > new file mode 100644 > index 0000000..e818901 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-altera.c > @@ -0,0 +1,510 @@ > +/* > + * Copyright Intel Corporation (C) 2017. > + * > + * This program is free software; you can redistribute it and/or modify = it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License= for > + * more details. > + * > + * You should have received a copy of the GNU General Public License alo= ng with > + * this program. If not, see . > + * > + * Based on the i2c-axxia.c driver. > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define ALTR_I2C_TFR_CMD 0x00 /* Transfer Command register */ > +#define ALTR_I2C_TFR_CMD_STA BIT(9) /* send START before byte */ > +#define ALTR_I2C_TFR_CMD_STO BIT(8) /* send STOP after byte */ > +#define ALTR_I2C_TFR_CMD_RW_D BIT(0) /* Direction of transfer */ > +#define ALTR_I2C_RX_DATA 0x04 /* RX data FIFO register */ > +#define ALTR_I2C_CTRL 0x08 /* Control register */ > +#define ALTR_I2C_CTRL_RXT_SHFT 4 /* RX FIFO Threshold */ > +#define ALTR_I2C_CTRL_TCT_SHFT 2 /* TFER CMD FIFO Threshold */ > +#define ALTR_I2C_CTRL_BSPEED BIT(1) /* Bus Speed (1=3DFast) */ > +#define ALTR_I2C_CTRL_EN BIT(0) /* Enable Core (1=3DEnable) */ > +#define ALTR_I2C_ISER 0x0C /* Interrupt Status Enable register */ > +#define ALTR_I2C_ISER_RXOF_EN BIT(4) /* Enable RX OVERFLOW IRQ */ > +#define ALTR_I2C_ISER_ARB_EN BIT(3) /* Enable ARB LOST IRQ */ > +#define ALTR_I2C_ISER_NACK_EN BIT(2) /* Enable NACK DET IRQ */ > +#define ALTR_I2C_ISER_RXRDY_EN BIT(1) /* Enable RX Ready IRQ */ > +#define ALTR_I2C_ISER_TXRDY_EN BIT(0) /* Enable TX Ready IRQ */ > +#define ALTR_I2C_ISR 0x10 /* Interrupt Status register */ > +#define ALTR_I2C_ISR_RXOF BIT(4) /* RX OVERFLOW IRQ */ > +#define ALTR_I2C_ISR_ARB BIT(3) /* ARB LOST IRQ */ > +#define ALTR_I2C_ISR_NACK BIT(2) /* NACK DET IRQ */ > +#define ALTR_I2C_ISR_RXRDY BIT(1) /* RX Ready IRQ */ > +#define ALTR_I2C_ISR_TXRDY BIT(0) /* TX Ready IRQ */ > +#define ALTR_I2C_STATUS 0x14 /* Status register */ > +#define ALTR_I2C_STAT_CORE BIT(0) /* Core Status (0=3Didle) */ > +#define ALTR_I2C_TC_FIFO_LVL 0x18 /* Transfer FIFO LVL register */ > +#define ALTR_I2C_RX_FIFO_LVL 0x1C /* Receive FIFO LVL register */ > +#define ALTR_I2C_SCL_LOW 0x20 /* SCL low count register */ > +#define ALTR_I2C_SCL_HIGH 0x24 /* SCL high count register */ > +#define ALTR_I2C_SDA_HOLD 0x28 /* SDA hold count register */ > + > +#define ALTR_I2C_ALL_IRQ (ALTR_I2C_ISR_RXOF | ALTR_I2C_ISR_ARB | \ > + ALTR_I2C_ISR_NACK | ALTR_I2C_ISR_RXRDY | \ > + ALTR_I2C_ISR_TXRDY) > + > +#define ALTR_I2C_THRESHOLD 0 /* IRQ Threshold at 1 element */ > +#define ALTR_I2C_DFLT_FIFO_SZ 4 > +#define ALTR_I2C_TIMEOUT 100000 /* 100ms */ > +#define ALTR_I2C_XFER_TIMEOUT (msecs_to_jiffies(250)) > + > +/** > + * altr_i2c_dev - I2C device context > + * @base: pointer to register struct > + * @msg: pointer to current message > + * @msg_len: number of bytes transferred in msg > + * @msg_err: error code for completed message > + * @msg_complete: xfer completion object > + * @dev: device reference > + * @adapter: core i2c abstraction > + * @i2c_clk: clock reference for i2c input clock > + * @bus_clk_rate: current i2c bus clock rate > + * @buf: ptr to msg buffer for easier use. > + * @fifo_size: size of the FIFO passed in. > + */ > +struct altr_i2c_dev { > + void __iomem *base; > + struct i2c_msg *msg; > + size_t msg_len; > + int msg_err; > + struct completion msg_complete; > + struct device *dev; > + struct i2c_adapter adapter; > + struct clk *i2c_clk; > + u32 bus_clk_rate; > + u8 *buf; > + u32 fifo_size; > + u32 isr_mask; The last one is not described in the kernel docs. > +}; > + > +static void i2c_int_enable(struct altr_i2c_dev *idev, u32 mask, bool ena= ble) > +{ > + u32 int_en =3D readl(idev->base + ALTR_I2C_ISER); > + > + if (enable) > + idev->isr_mask =3D int_en | mask; > + else > + idev->isr_mask =3D int_en & ~mask; > + > + writel(idev->isr_mask, idev->base + ALTR_I2C_ISER); > +} > + > +static void i2c_int_clear(struct altr_i2c_dev *idev, u32 mask) > +{ > + u32 int_en =3D readl(idev->base + ALTR_I2C_ISR); > + > + writel(int_en | mask, idev->base + ALTR_I2C_ISR); > +} Those two functions would also suit an altr_ prefix. > + > +static void altr_i2c_core_disable(struct altr_i2c_dev *idev) > +{ > + u32 tmp =3D readl(idev->base + ALTR_I2C_CTRL); > + > + writel(tmp & ~ALTR_I2C_CTRL_EN, idev->base + ALTR_I2C_CTRL); > +} > + > +static void altr_i2c_core_enable(struct altr_i2c_dev *idev) > +{ > + u32 tmp =3D readl(idev->base + ALTR_I2C_CTRL); > + > + writel(tmp | ALTR_I2C_CTRL_EN, idev->base + ALTR_I2C_CTRL); > +} > + > +static void altr_i2c_reset(struct altr_i2c_dev *idev) > +{ > + altr_i2c_core_disable(idev); > + altr_i2c_core_enable(idev); > +} > + > +static void altr_i2c_recover(struct altr_i2c_dev *idev) > +{ > + altr_i2c_reset(idev); > + /* Clock start bit + 8 bits + stop bit out */ Really 8? It should be 9 (ACK bit). > + writel(ALTR_I2C_TFR_CMD_STA | ALTR_I2C_TFR_CMD_STO, > + idev->base + ALTR_I2C_TFR_CMD); > + altr_i2c_reset(idev); Why the second reset? > + > + i2c_recover_bus(&idev->adapter); This will return an error since you don't have a struct i2c_bus_recovery_info defined. This whole recovery looks fishy, maybe it should be dropped now and added incrementally? > +} > + > +static inline void altr_i2c_stop(struct altr_i2c_dev *idev) > +{ > + writel(ALTR_I2C_TFR_CMD_STO, idev->base + ALTR_I2C_TFR_CMD); > +} > + > +static void altr_i2c_init(struct altr_i2c_dev *idev) > +{ > + u32 divisor =3D clk_get_rate(idev->i2c_clk) / idev->bus_clk_rate; > + u32 clk_mhz =3D clk_get_rate(idev->i2c_clk) / 1000000; > + u32 tmp =3D (ALTR_I2C_THRESHOLD << ALTR_I2C_CTRL_RXT_SHFT) | > + (ALTR_I2C_THRESHOLD << ALTR_I2C_CTRL_TCT_SHFT); > + u32 t_high, t_low; > + > + if (idev->bus_clk_rate <=3D 100000) { > + tmp &=3D ~ALTR_I2C_CTRL_BSPEED; > + /* Standard mode SCL 50/50 */ > + t_high =3D divisor * 1 / 2; > + t_low =3D divisor * 1 / 2; > + } else { > + tmp |=3D ALTR_I2C_CTRL_BSPEED; > + /* Fast mode SCL 33/66 */ > + t_high =3D divisor * 1 / 3; > + t_low =3D divisor * 2 / 3; > + } > + writel(tmp, idev->base + ALTR_I2C_CTRL); > + > + dev_dbg(idev->dev, "rate=3D%uHz per_clk=3D%uMHz -> ratio=3D1:%u\n", > + idev->bus_clk_rate, clk_mhz, divisor); > + > + /* Reset controller */ > + altr_i2c_reset(idev); > + > + /* SCL High Time */ > + writel(t_high, idev->base + ALTR_I2C_SCL_HIGH); > + /* SCL Low Time */ > + writel(t_low, idev->base + ALTR_I2C_SCL_LOW); > + /* SDA Hold Time, 300ns */ > + writel(div_u64(300 * clk_mhz, 1000), idev->base + ALTR_I2C_SDA_HOLD); > + > + /* Mask all master interrupt bits */ > + i2c_int_enable(idev, ALTR_I2C_ALL_IRQ, false); > +} > + > +static int i2c_m_rd(const struct i2c_msg *msg) > +{ > + return (msg->flags & I2C_M_RD) !=3D 0; > +} I'll leave it to you, but I'd think an extra function doesn't really improve readability here. > + > +/** > + * altr_i2c_transfer - On the last byte to be transmitted, send > + * a Stop bit on the last byte. > + */ > +static void altr_i2c_transfer(struct altr_i2c_dev *idev, u32 data) > +{ > + /* On the last byte to be transmitted, send STOP */ > + if (idev->msg_len =3D=3D 1) > + data |=3D ALTR_I2C_TFR_CMD_STO; > + if (idev->msg_len > 0) > + writel(data, idev->base + ALTR_I2C_TFR_CMD); > +} > + > +/** > + * altr_i2c_empty_rx_fifo - Fetch data from RX FIFO until end of > + * transfer. Send a Stop bit on the last byte. > + */ > +static void altr_i2c_empty_rx_fifo(struct altr_i2c_dev *idev) > +{ > + size_t rx_fifo_avail =3D readl(idev->base + ALTR_I2C_RX_FIFO_LVL); > + int bytes_to_transfer =3D min(rx_fifo_avail, idev->msg_len); > + > + while (bytes_to_transfer-- > 0) { > + *idev->buf++ =3D readl(idev->base + ALTR_I2C_RX_DATA); > + idev->msg_len--; > + altr_i2c_transfer(idev, 0); > + } > +} > + > +/** > + * altr_i2c_fill_tx_fifo - Fill TX FIFO from current message buffer. > + * @return: Number of bytes left to transfer. > + */ > +static int altr_i2c_fill_tx_fifo(struct altr_i2c_dev *idev) > +{ > + size_t tx_fifo_avail =3D idev->fifo_size - readl(idev->base + > + ALTR_I2C_TC_FIFO_LVL); > + int bytes_to_transfer =3D min(tx_fifo_avail, idev->msg_len); > + int ret =3D idev->msg_len - bytes_to_transfer; > + > + while (bytes_to_transfer-- > 0) { > + altr_i2c_transfer(idev, *idev->buf++); > + idev->msg_len--; > + } > + > + return ret; > +} > + > +static irqreturn_t altr_i2c_isr(int irq, void *_dev) > +{ > + int ret, read; > + struct altr_i2c_dev *idev =3D _dev; > + /* Read IRQ status but only interested in Enabled IRQs. */ > + u32 status =3D readl(idev->base + ALTR_I2C_ISR) & idev->isr_mask; > + > + if (!idev->msg) { > + dev_warn(idev->dev, "unexpected interrupt\n"); > + goto out; Won't you get an interrupt storm if you don't use any i2c_int_clear()? > + } > + read =3D i2c_m_rd(idev->msg); > + > + /* handle Lost Arbitration */ > + if (unlikely(status & ALTR_I2C_ISR_ARB)) { > + dev_err(idev->dev, "%s: arbitration lost\n", __func__); Drop the message, it is not an error, but a to be expected bus condition in multi-master setups. > + i2c_int_clear(idev, ALTR_I2C_ISR_ARB); > + idev->msg_err =3D -EAGAIN; > + goto complete; > + } > + > + if (unlikely(status & ALTR_I2C_ISR_NACK)) { > + dev_dbg(idev->dev, "%s: could not get ACK\n", __func__); > + idev->msg_err =3D -ENXIO; > + i2c_int_clear(idev, ALTR_I2C_ISR_NACK); > + altr_i2c_stop(idev); > + goto complete; > + } > + > + /* handle RX FIFO Overflow */ > + if (read && unlikely(status & ALTR_I2C_ISR_RXOF)) { > + altr_i2c_empty_rx_fifo(idev); > + i2c_int_clear(idev, ALTR_I2C_ISR_RXRDY); > + altr_i2c_stop(idev); > + dev_err(idev->dev, "%s: RX FIFO Overflow\n", __func__); > + goto complete; > + } > + > + /* RX FIFO needs service? */ > + if (read && (status & ALTR_I2C_ISR_RXRDY)) { > + altr_i2c_empty_rx_fifo(idev); > + i2c_int_clear(idev, ALTR_I2C_ISR_RXRDY); > + if (!idev->msg_len) > + goto complete; > + > + goto out; > + } > + > + /* TX FIFO needs service? */ > + if (!read && (status & ALTR_I2C_ISR_TXRDY)) { > + i2c_int_clear(idev, ALTR_I2C_ISR_TXRDY); > + if (!altr_i2c_fill_tx_fifo(idev)) > + goto complete; > + > + goto out; A bit too much goto in here for my taste. What about using a boolean 'complete' variable which gets set or cleared and have an 'if (complete)' at the end of this routine? > + } > + > +complete: > + /* Wait for the Core to finish */ > + ret =3D readl_poll_timeout_atomic(idev->base + ALTR_I2C_STATUS, status, > + ((status & ALTR_I2C_STAT_CORE) =3D=3D 0), > + 1, ALTR_I2C_TIMEOUT); Why do you need this polling in an interrupt? > + if (ret) > + dev_err(idev->dev, "%s: message timeout\n", __func__); > + i2c_int_enable(idev, ALTR_I2C_ALL_IRQ, false); > + i2c_int_clear(idev, ALTR_I2C_ALL_IRQ); > + complete(&idev->msg_complete); > + dev_dbg(idev->dev, "%s: Message Complete\n", __func__); > + > +out: > + return IRQ_HANDLED; > +} > + > +static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *= msg) > +{ > + u32 imask =3D ALTR_I2C_ISR_RXOF | ALTR_I2C_ISR_ARB | ALTR_I2C_ISR_NACK; > + unsigned long time_left; > + u32 value; > + u8 addr =3D i2c_8bit_addr_from_msg(msg); > + > + idev->msg =3D msg; > + idev->msg_len =3D msg->len; > + idev->buf =3D msg->buf; > + idev->msg_err =3D 0; > + reinit_completion(&idev->msg_complete); > + altr_i2c_core_enable(idev); > + > + /* Make sure RX FIFO is empty */ > + do { > + readl(idev->base + ALTR_I2C_RX_DATA); > + } while (readl(idev->base + ALTR_I2C_RX_FIFO_LVL)); > + > + writel(ALTR_I2C_TFR_CMD_STA | addr, idev->base + ALTR_I2C_TFR_CMD); > + > + if (i2c_m_rd(msg)) { > + imask |=3D ALTR_I2C_ISER_RXOF_EN | ALTR_I2C_ISER_RXRDY_EN; > + i2c_int_enable(idev, imask, true); > + /* write the first byte to start the RX */ > + altr_i2c_transfer(idev, 0); > + } else { > + imask |=3D ALTR_I2C_ISR_TXRDY; > + i2c_int_enable(idev, imask, true); > + altr_i2c_fill_tx_fifo(idev); > + } > + > + time_left =3D wait_for_completion_timeout(&idev->msg_complete, > + ALTR_I2C_XFER_TIMEOUT); > + i2c_int_enable(idev, imask, false); > + > + value =3D readl(idev->base + ALTR_I2C_STATUS) & ALTR_I2C_STAT_CORE; > + if (value) > + dev_err(idev->dev, "%s: Core Status not IDLE...\n", __func__); __func__ with dev_* is 99,9% superfluous. > + > + if (time_left =3D=3D 0) { > + idev->msg_err =3D -ETIMEDOUT; > + dev_err(idev->dev, "%s: Transaction timed out.\n", __func__); No error message here. This can happen when an EEPROM is currently erasing. > + altr_i2c_recover(idev); And no need to reset the bus! Only if SDA is stuck low. > + } > + > + if (unlikely(idev->msg_err) && idev->msg_err !=3D -ENXIO) > + altr_i2c_init(idev); Why do you need to reinit on NACK? > + > + altr_i2c_core_disable(idev); > + > + return idev->msg_err; > +} > + > +static int > +altr_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > +{ > + struct altr_i2c_dev *idev =3D i2c_get_adapdata(adap); > + int i, ret; > + > + for (i =3D 0; i < num; i++) { > + ret =3D altr_i2c_xfer_msg(idev, msgs++); > + if (ret) > + return ret; > + } > + return num; > +} > + > +static u32 altr_i2c_func(struct i2c_adapter *adap) > +{ > + return I2C_FUNC_I2C; > +} No emulated SMBUS? > + > +static const struct i2c_algorithm altr_i2c_algo =3D { > + .master_xfer =3D altr_i2c_xfer, > + .functionality =3D altr_i2c_func, > +}; > + > +static int altr_i2c_probe(struct platform_device *pdev) > +{ > + struct altr_i2c_dev *idev =3D NULL; > + struct resource *res; > + int irq, ret; > + u32 val; > + > + idev =3D devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL); > + if (!idev) > + return -ENOMEM; > + > + res =3D platform_get_resource(pdev, IORESOURCE_MEM, 0); > + idev->base =3D devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(idev->base)) > + return PTR_ERR(idev->base); > + > + irq =3D platform_get_irq(pdev, 0); > + if (irq < 0) { > + dev_err(&pdev->dev, "missing interrupt resource\n"); > + return irq; > + } > + > + idev->i2c_clk =3D devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(idev->i2c_clk)) { > + dev_err(&pdev->dev, "missing clock\n"); > + return PTR_ERR(idev->i2c_clk); > + } > + > + idev->dev =3D &pdev->dev; > + init_completion(&idev->msg_complete); > + > + val =3D device_property_read_u32(idev->dev, "fifo-size", > + &idev->fifo_size); > + if (val) { > + dev_err(&pdev->dev, "FIFO size set to default of %d\n", > + ALTR_I2C_DFLT_FIFO_SZ); > + idev->fifo_size =3D ALTR_I2C_DFLT_FIFO_SZ; > + } > + > + val =3D device_property_read_u32(idev->dev, "clock-frequency", > + &idev->bus_clk_rate); > + if (val) { > + dev_err(&pdev->dev, "Default to 100kHz\n"); > + idev->bus_clk_rate =3D 100000; /* default clock rate */ > + } > + > + if (idev->bus_clk_rate > 400000) { > + dev_err(&pdev->dev, "invalid clock-frequency %d\n", > + idev->bus_clk_rate); > + return -EINVAL; > + } > + > + ret =3D devm_request_irq(&pdev->dev, irq, altr_i2c_isr, 0, > + pdev->name, idev); > + if (ret) { > + dev_err(&pdev->dev, "failed to claim IRQ %d\n", irq); > + return ret; > + } > + > + ret =3D clk_prepare_enable(idev->i2c_clk); > + if (ret) { > + dev_err(&pdev->dev, "failed to enable clock\n"); > + return ret; > + } > + > + altr_i2c_init(idev); > + > + i2c_set_adapdata(&idev->adapter, idev); > + strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name)); > + idev->adapter.owner =3D THIS_MODULE; > + idev->adapter.algo =3D &altr_i2c_algo; > + idev->adapter.dev.parent =3D &pdev->dev; > + idev->adapter.dev.of_node =3D pdev->dev.of_node; > + > + platform_set_drvdata(pdev, idev); > + > + ret =3D i2c_add_adapter(&idev->adapter); > + if (ret) { > + clk_disable_unprepare(idev->i2c_clk); > + return ret; > + } > + dev_info(&pdev->dev, "Altera SoftIP I2C Probe Complete\n"); > + > + return 0; > +} > + > +static int altr_i2c_remove(struct platform_device *pdev) > +{ > + struct altr_i2c_dev *idev =3D platform_get_drvdata(pdev); > + > + clk_disable_unprepare(idev->i2c_clk); > + i2c_del_adapter(&idev->adapter); > + > + return 0; > +} > + > +/* Match table for of_platform binding */ > +static const struct of_device_id altr_i2c_of_match[] =3D { > + { .compatible =3D "altr,softip-i2c-v1.0" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, altr_i2c_of_match); > + > +static struct platform_driver altr_i2c_driver =3D { > + .probe =3D altr_i2c_probe, > + .remove =3D altr_i2c_remove, > + .driver =3D { > + .name =3D "altera-i2c", > + .of_match_table =3D altr_i2c_of_match, > + }, > +}; > + > +module_platform_driver(altr_i2c_driver); > + > +MODULE_DESCRIPTION("Altera Soft IP I2C bus driver"); > +MODULE_AUTHOR("Thor Thayer "); > +MODULE_LICENSE("GPL v2"); > --=20 > 2.7.4 >=20 --75tqzgfvrtlyo56b Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAll/MSkACgkQFA3kzBSg KbZlWw/9EPGwWNgm0bZkW6bXdK2dXUxbpzfNzB4+t4TO5MKnjYALDsm/AEDGTBHR p1VNaSvJeV9fvHD6TL9D0QHSXtCnaaN9nAfIdxg/KlIhIVBhqI9I5hxG9ZBEw1tt 07TJFe12Fb0rKb1kzvJ3LTizmeI2X/g1oUCtHW//6nG1V4ypp9/DjfxIvKQbTo08 /iJoqs0ujcCrTHhwJfCVnjKzNz92Uly3N4HByMzMp/kX12B0qcOyjZxN/yfe/G4C Mf25e6kDn5Y6xjrbOL1Pwbt2WAptvtKD9Ibm87Pa6t1nWPUy2LKbZ9DdQlTqvCzL Y+vQY/am395fMkv0INf4OrvcP0uUj+mEW/VG2j4XODZbmouVehhFJx+lBv5aV2F3 +Rc4K5+nlzMwsDBeDdPJs0sQIgp0+nZGubonGQwhdEVUIqVQQQzQInN1rJy2sa5B RXqAnXPkmU7pNq2USVIoKsx60T8a/LmT5/0DtQleaJTy4h1gLMaEB6gVbtvn9XwH PX604Yp+mU4oIDxzzzqZWJer0HPNczU05UeoNDCXmeK8AsGe/msnOg8OgthTagyC 4VABtZGI0gGVJ8CsQ476jPp77NuRxGr2aTw1dPflgiuH2hbumyBwLSkpMoW5mLEa kd3ZFRRiHu7T17/NGggGlz3JhvIjway1w13o9vlkE4Az1woS3ek= =+pNY -----END PGP SIGNATURE----- --75tqzgfvrtlyo56b--