From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753021AbaFGRow (ORCPT ); Sat, 7 Jun 2014 13:44:52 -0400 Received: from mout.kundenserver.de ([212.227.17.13]:51798 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752583AbaFGRou convert rfc822-to-8bit (ORCPT ); Sat, 7 Jun 2014 13:44:50 -0400 From: Max Schwarz To: Wolfram Sang Cc: Grant Likely , Rob Herring , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Heiko =?ISO-8859-1?Q?St=FCbner?= , Maxime Ripard , kfx@rock-chips.com Subject: [PATCH v5] i2c: add driver for Rockchip RK3xxx SoC I2C adapter Date: Sat, 07 Jun 2014 19:44:43 +0200 Message-ID: <1622583.1BSVBxxgia@typ> User-Agent: KMail/4.13 (Linux/3.13.0-29-generic; KDE/4.13.0; x86_64; ; ) In-Reply-To: <1956748.HoDAyYWJMb@typ> References: <5192968.EzcUiXba22@typ> <1956748.HoDAyYWJMb@typ> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" X-Provags-ID: V02:K0:PFSHbfcJdLYHGtYR4emdpX4r2ckglIgGn5QGX4+Z9A+ W8U0znZus6L0HHjIeb+YkveCaosSNiCd4BXTl7ANxr7FjvJc/V a5L+QvcLcbECFHydytFxsgu3TjtpnEhMIfFYlh47IHhrnvwx2q kIbBzyflCqTbc/2CDlSwtTMJQ4O57ZZq9zKHZ28ybYHhAYCwbI 5gstV1mMps9VNU0hGT9maFeWWDHbS/5op3qLXrz4XzjLVwVsYy nao9GAe2noHBaL+8BrfM/AC098/4ykrlq81yvMnb12KCOYlqTV amsV3JRGttxt+5Rey2lgo4qDlBuhYkKHS/1lQPn5dujKMIyxA= = Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Driver for the native I2C adapter found in Rockchip RK3xxx SoCs. Configuration is only possible through devicetree. The driver is interrupt driven and supports the I2C_M_IGNORE_NAK mangling bit. Signed-off-by: Max Schwarz --- Sorry for the resend, I forgot to CC the developers at Rockchip, which I promised to do. Patch is unchanged. The driver cannot be used without a proper clock driver supporting rate calculation, such as Heiko Stübner's RK3xxx clock driver series [1]. Changes since v4: - fixed a bug in message counting in rk3x_i2c_xfer() - Found/suggested by Wolfram Sang: * fixed style issues * fixed sorting in Kconfig, Makefile * removed unneeded fields from struct rk3x_i2c * REPEATED_START between msgs of one transfer * fixed wrong error code on NAK * support for SMB_QUICK (len == 0) * removed unneeded DT check & alias handling * sanity check for clock-frequency Changes since v3: - fixed style issues found by Maxime Ripard - use dt alias id to calculate the bit offset in GRF, as suggested by Maxime Ripard - also use dt alias id for i2c_add_numbered_adapter() Changes since v2: - support for the new GRF syscon mapping by Heiko Stübner - probe error handling improvements by Heiko Stübner - fixed wrong remove() order found by Heiko Stübner - removed unnecessary clk_enable() during probe - removed switch back to old interface during remove Changes since v1: - dt property names "rockchip,*" suggested by Heiko Stübner - fixed overly specific RK3188 comment (Heiko Stübner) The dts files needed for testing on Radxa Rock are in my tree at https://github.com/xqms/linux.git topic/i2c-rk3x-clean-v4 [1]: http://www.spinics.net/lists/arm-kernel/msg334495.html Documentation/devicetree/bindings/i2c/i2c-rk3x.txt | 42 ++ drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-rk3x.c | 769 +++++++++++++++++++++ 4 files changed, 822 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-rk3x.txt create mode 100644 drivers/i2c/busses/i2c-rk3x.c diff --git a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt new file mode 100644 index 0000000..dde6c22 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt @@ -0,0 +1,42 @@ +* Rockchip RK3xxx I2C controller + +This driver interfaces with the native I2C controller present in Rockchip +RK3xxx SoCs. + +Required properties : + + - reg : Offset and length of the register set for the device + - compatible : should be "rockchip,rk3066-i2c", "rockchip,rk3188-i2c" or + "rockchip,rk3288-i2c". + - interrupts : interrupt number + - clocks : parent clock + +Required on RK3066, RK3188 : + + - rockchip,grf : the phandle of the syscon node for the general register + file (GRF) + - on those SoCs an alias with the correct I2C bus ID (bit offset in the GRF) + is also required. + +Optional properties : + + - clock-frequency : SCL frequency to use (in Hz). If omitted, 100kHz is used. + +Example: + +aliases { + i2c0 = &i2c0; +} + +i2c0: i2c@2002d000 { + compatible = "rockchip,rk3188-i2c"; + reg = <0x2002d000 0x1000>; + interrupts = ; + #address-cells = <1>; + #size-cells = <0>; + + rockchip,grf = <&grf>; + + clock-names = "i2c"; + clocks = <&cru PCLK_I2C0>; +}; diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 7ccc51e..39307d0 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -676,6 +676,16 @@ config I2C_RIIC This driver can also be built as a module. If so, the module will be called i2c-riic. +config I2C_RK3X + tristate "Rockchip RK3xxx I2C adapter" + depends on OF + help + Say Y here to include support for the I2C adapter in Rockchip RK3xxx + SoCs. + + This driver can also be built as a module. If so, the module will + be called i2c-rk3x. + config HAVE_S3C2410_I2C bool help diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 413d062..5582cf9 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -66,6 +66,7 @@ obj-$(CONFIG_I2C_PXA) += i2c-pxa.o obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o obj-$(CONFIG_I2C_QUP) += i2c-qup.o obj-$(CONFIG_I2C_RIIC) += i2c-riic.o +obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o obj-$(CONFIG_I2C_S6000) += i2c-s6000.o obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c new file mode 100644 index 0000000..7a430f4 --- /dev/null +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -0,0 +1,769 @@ +/* + * Driver for I2C adapter in Rockchip RK3xxx SoC + * + * Max Schwarz + * based on the patches by Rockchip Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* Register Map */ +#define REG_CON 0x00 /* control register */ +#define REG_CLKDIV 0x04 /* clock divisor register */ +#define REG_MRXADDR 0x08 /* slave address for REGISTER_TX */ +#define REG_MRXRADDR 0x0c /* slave register address for REGISTER_TX */ +#define REG_MTXCNT 0x10 /* number of bytes to be transmitted */ +#define REG_MRXCNT 0x14 /* number of bytes to be received */ +#define REG_IEN 0x18 /* interrupt enable */ +#define REG_IPD 0x1c /* interrupt pending */ +#define REG_FCNT 0x20 /* finished count */ + +/* Data buffer offsets */ +#define TXBUFFER_BASE 0x100 +#define RXBUFFER_BASE 0x200 + +/* REG_CON bits */ +#define REG_CON_EN BIT(0) +enum { + REG_CON_MOD_TX = 0, /* transmit data */ + REG_CON_MOD_REGISTER_TX, /* select register and restart */ + REG_CON_MOD_RX, /* receive data */ + REG_CON_MOD_REGISTER_RX, /* broken: transmits read addr AND writes + * register addr */ +}; +#define REG_CON_MOD(mod) ((mod) << 1) +#define REG_CON_MOD_MASK (BIT(1) | BIT(2)) +#define REG_CON_START BIT(3) +#define REG_CON_STOP BIT(4) +#define REG_CON_LASTACK BIT(5) /* 1: do not send ACK after last receive */ +#define REG_CON_ACTACK BIT(6) /* 1: stop if NACK is received */ + +/* REG_MRXADDR bits */ +#define REG_MRXADDR_VALID(x) BIT(24 + (x)) /* [x*8+7:x*8] of MRX[R]ADDR valid */ + +/* REG_IEN/REG_IPD bits */ +#define REG_INT_BTF BIT(0) /* a byte was transmitted */ +#define REG_INT_BRF BIT(1) /* a byte was received */ +#define REG_INT_MBTF BIT(2) /* master data transmit finished */ +#define REG_INT_MBRF BIT(3) /* master data receive finished */ +#define REG_INT_START BIT(4) /* START condition generated */ +#define REG_INT_STOP BIT(5) /* STOP condition generated */ +#define REG_INT_NAKRCV BIT(6) /* NACK received */ +#define REG_INT_ALL 0x7f + +/* Constants */ +#define WAIT_TIMEOUT 200 /* ms */ +#define DEFAULT_SCL_RATE (100 * 1000) /* Hz */ + +enum rk3x_i2c_state { + STATE_IDLE, + STATE_START, + STATE_READ, + STATE_WRITE, + STATE_STOP +}; + +/** + * @grf_offset: offset inside the grf regmap for setting the i2c type + */ +struct rk3x_i2c_soc_data { + int grf_offset; +}; + +struct rk3x_i2c { + struct i2c_adapter adap; + struct device *dev; + struct rk3x_i2c_soc_data *soc_data; + + /* Hardware resources */ + void __iomem *regs; + struct clk *clk; + + /* Settings */ + unsigned int scl_frequency; + + /* Synchronization & notification */ + spinlock_t lock; + wait_queue_head_t wait; + bool busy; + + /* Current message */ + struct i2c_msg *msg; + u8 addr; + unsigned int mode; + bool is_last_msg; + + /* I2C state machine */ + enum rk3x_i2c_state state; + unsigned int processed; /* sent/received bytes */ + int error; +}; + +static inline void i2c_writel(struct rk3x_i2c *i2c, u32 value, + unsigned int offset) +{ + writel(value, i2c->regs + offset); +} + +static inline u32 i2c_readl(struct rk3x_i2c *i2c, unsigned int offset) +{ + return readl(i2c->regs + offset); +} + +/* Reset all interrupt pending bits */ +static inline void rk3x_i2c_clean_ipd(struct rk3x_i2c *i2c) +{ + i2c_writel(i2c, REG_INT_ALL, REG_IPD); +} + +/** + * Generate a START condition, which triggers a REG_INT_START interrupt. + */ +static void rk3x_i2c_start(struct rk3x_i2c *i2c) +{ + u32 val; + + dev_dbg(i2c->dev, "start\n"); + + rk3x_i2c_clean_ipd(i2c); + i2c_writel(i2c, REG_INT_START, REG_IEN); + + /* enable adapter with correct mode, send START condition */ + val = REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START; + + /* if we want to react to NACK, set ACTACK bit */ + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) + val |= REG_CON_ACTACK; + + i2c_writel(i2c, val, REG_CON); +} + +/** + * Generate a STOP condition, which triggers a REG_INT_STOP interrupt. + * + * @error: Error code to return in rk3x_i2c_xfer + */ +static void rk3x_i2c_stop(struct rk3x_i2c *i2c, int error) +{ + unsigned int ctrl; + + i2c->processed = 0; + i2c->msg = 0; + i2c->error = error; + + if (i2c->is_last_msg) { + /* Enable stop interrupt */ + i2c_writel(i2c, REG_INT_STOP, REG_IEN); + + i2c->state = STATE_STOP; + + ctrl = i2c_readl(i2c, REG_CON); + ctrl |= REG_CON_STOP; + i2c_writel(i2c, ctrl, REG_CON); + } else { + /* Signal rk3x_i2c_xfer to start the next message. */ + i2c->busy = 0; + i2c->state = STATE_IDLE; + + /* + * The HW is actually not capable of REPEATED START. But we can + * get the intended effect by resetting its internal state + * and issuing an ordinary START. + */ + i2c_writel(i2c, 0, REG_CON); + + /* signal that we are finished with the current msg */ + wake_up(&i2c->wait); + } +} + +/** + * Setup a read according to i2c->msg + */ +static void rk3x_i2c_prepare_read(struct rk3x_i2c *i2c) +{ + unsigned int len = i2c->msg->len - i2c->processed; + u32 con; + + con = i2c_readl(i2c, REG_CON); + + /* + * The hw can read up to 32 bytes at a time. If we need more than one + * chunk, send an ACK after the last byte of the current chunk. + */ + if (unlikely(len > 32)) { + len = 32; + con &= ~REG_CON_LASTACK; + } else { + con |= REG_CON_LASTACK; + } + + /* make sure we are in plain RX mode if we read a second chunk */ + if (i2c->processed != 0) { + con &= ~REG_CON_MOD_MASK; + con |= REG_CON_MOD(REG_CON_MOD_RX); + } + + i2c_writel(i2c, con, REG_CON); + i2c_writel(i2c, len, REG_MRXCNT); +} + +/** + * Fill the transmit buffer with data from i2c->msg + */ +static void rk3x_i2c_fill_transmit_buf(struct rk3x_i2c *i2c) +{ + unsigned int i, j; + u32 cnt = 0; + u32 val; + u8 byte; + + for (i = 0; i < 8; ++i) { + val = 0; + for (j = 0; j < 4; ++j) { + if (i2c->processed == i2c->msg->len) + break; + + if (i2c->processed == 0 && cnt == 0) + byte = (i2c->addr & 0x7f) << 1; + else + byte = i2c->msg->buf[i2c->processed++]; + + val |= byte << (j * 8); + cnt++; + } + + i2c_writel(i2c, val, TXBUFFER_BASE + 4 * i); + + if (i2c->processed == i2c->msg->len) + break; + } + + i2c_writel(i2c, cnt, REG_MTXCNT); +} + + +/* IRQ handlers for individual states */ + +static void rk3x_i2c_handle_start(struct rk3x_i2c *i2c, unsigned int ipd) +{ + if (!(ipd & REG_INT_START)) { + rk3x_i2c_stop(i2c, -EIO); + dev_warn(i2c->dev, "unexpected irq in START: 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + return; + } + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_START, REG_IPD); + + /* disable start bit */ + i2c_writel(i2c, i2c_readl(i2c, REG_CON) & ~REG_CON_START, REG_CON); + + /* enable appropriate interrupts and transition */ + if (i2c->mode == REG_CON_MOD_TX) { + i2c_writel(i2c, REG_INT_MBTF | REG_INT_NAKRCV, REG_IEN); + i2c->state = STATE_WRITE; + rk3x_i2c_fill_transmit_buf(i2c); + } else { + /* in any other case, we are going to be reading. */ + i2c_writel(i2c, REG_INT_MBRF | REG_INT_NAKRCV, REG_IEN); + i2c->state = STATE_READ; + rk3x_i2c_prepare_read(i2c); + } +} + +static void rk3x_i2c_handle_write(struct rk3x_i2c *i2c, unsigned int ipd) +{ + if (!(ipd & REG_INT_MBTF)) { + rk3x_i2c_stop(i2c, -EIO); + dev_err(i2c->dev, "unexpected irq in WRITE: 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + return; + } + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_MBTF, REG_IPD); + + /* are we finished? */ + if (i2c->processed == i2c->msg->len) + rk3x_i2c_stop(i2c, i2c->error); + else + rk3x_i2c_fill_transmit_buf(i2c); +} + +static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd) +{ + unsigned int i; + unsigned int len = i2c->msg->len - i2c->processed; + unsigned int val; + u8 byte; + + /* we only care for MBRF here. */ + if (!(ipd & REG_INT_MBRF)) + return; + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_MBRF, REG_IPD); + + /* read the data from receive buffer */ + for (i = 0; i < len; ++i) { + if (i % 4 == 0) + val = i2c_readl(i2c, RXBUFFER_BASE + (i / 4) * 4); + + byte = (val >> ((i % 4) * 8)) & 0xff; + i2c->msg->buf[i2c->processed++] = byte; + } + + /* are we finished? */ + if (i2c->processed == i2c->msg->len) + rk3x_i2c_stop(i2c, i2c->error); + else + rk3x_i2c_prepare_read(i2c); +} + +static void rk3x_i2c_handle_stop(struct rk3x_i2c *i2c, unsigned int ipd) +{ + unsigned int con; + + if (!(ipd & REG_INT_STOP)) { + rk3x_i2c_stop(i2c, -EIO); + dev_err(i2c->dev, "unexpected irq in STOP: 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + return; + } + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_STOP, REG_IPD); + + /* disable STOP bit */ + con = i2c_readl(i2c, REG_CON); + con &= ~REG_CON_STOP; + i2c_writel(i2c, con, REG_CON); + + i2c->busy = 0; + i2c->state = STATE_IDLE; + + /* signal rk3x_i2c_xfer that we are finished */ + wake_up(&i2c->wait); +} + +static irqreturn_t rk3x_i2c_irq(int irqno, void *dev_id) +{ + struct rk3x_i2c *i2c = dev_id; + unsigned int ipd; + + spin_lock(&i2c->lock); + + ipd = i2c_readl(i2c, REG_IPD); + if (i2c->state == STATE_IDLE) { + dev_warn(i2c->dev, "irq in STATE_IDLE, ipd = 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + goto out; + } + + dev_dbg(i2c->dev, "IRQ: state %d, ipd: %x\n", i2c->state, ipd); + + /* Clean interrupt bits we don't care about */ + ipd &= ~(REG_INT_BRF | REG_INT_BTF); + + if (ipd & REG_INT_NAKRCV) { + /* + * We got a NACK in the last operation. Depending on whether + * IGNORE_NAK is set, we have to stop the operation and report + * an error. + */ + i2c_writel(i2c, REG_INT_NAKRCV, REG_IPD); + + ipd &= ~REG_INT_NAKRCV; + + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) + rk3x_i2c_stop(i2c, -ENXIO); + } + + /* is there anything left to handle? */ + if (unlikely(ipd == 0)) + goto out; + + switch (i2c->state) { + case STATE_START: + rk3x_i2c_handle_start(i2c, ipd); + break; + case STATE_WRITE: + rk3x_i2c_handle_write(i2c, ipd); + break; + case STATE_READ: + rk3x_i2c_handle_read(i2c, ipd); + break; + case STATE_STOP: + rk3x_i2c_handle_stop(i2c, ipd); + break; + case STATE_IDLE: + break; + } + +out: + spin_unlock(&i2c->lock); + return IRQ_HANDLED; +} + +static void rk3x_i2c_set_scl_rate(struct rk3x_i2c *i2c, unsigned long scl_rate) +{ + unsigned long i2c_rate = clk_get_rate(i2c->clk); + unsigned int div; + + /* SCL rate = (clk rate) / (8 * DIV) */ + div = DIV_ROUND_UP(i2c_rate, scl_rate * 8); + + /* The lower and upper half of the CLKDIV reg describe the length of + * SCL low & high periods. */ + div = DIV_ROUND_UP(div, 2); + + i2c_writel(i2c, (div << 16) | (div & 0xffff), REG_CLKDIV); +} + +/** + * Setup I2C registers for an I2C operation specified by msgs, num. + * + * Must be called with i2c->lock held. + * + * @msgs: I2C msgs to process + * @num: Number of msgs + * + * returns: Number of I2C msgs processed or negative in case of error + */ +static int rk3x_i2c_setup(struct rk3x_i2c *i2c, struct i2c_msg *msgs, int num) +{ + u32 addr = (msgs[0].addr & 0x7f) << 1; + int ret = 0; + + /* + * The I2C adapter can issue a small (len < 4) write packet before + * reading. This speeds up SMBus-style register reads. + * The MRXADDR/MRXRADDR hold the slave address and the slave register + * address in this case. + */ + + if (num >= 2 && msgs[0].len < 4 + && !(msgs[0].flags & I2C_M_RD) + && (msgs[1].flags & I2C_M_RD)) { + u32 reg_addr = 0; + int i; + + dev_dbg(i2c->dev, "Combined write/read from addr 0x%x\n", + addr >> 1); + + /* Fill MRXRADDR with the register address(es) */ + for (i = 0; i < msgs[0].len; ++i) { + reg_addr |= msgs[0].buf[i] << (i * 8); + reg_addr |= REG_MRXADDR_VALID(i); + } + + /* msgs[0] is handled by hw. */ + i2c->msg = &msgs[1]; + + i2c->mode = REG_CON_MOD_REGISTER_TX; + + i2c_writel(i2c, addr | REG_MRXADDR_VALID(0), REG_MRXADDR); + i2c_writel(i2c, reg_addr, REG_MRXRADDR); + + ret = 2; + } else { + /* + * We'll have to do it the boring way and process the msgs + * one-by-one. + */ + + if (msgs[0].flags & I2C_M_RD) { + addr |= 1; /* set read bit */ + + /* + * We have to transmit the slave addr first. Use + * MOD_REGISTER_TX for that purpose. + */ + i2c->mode = REG_CON_MOD_REGISTER_TX; + i2c_writel(i2c, addr | REG_MRXADDR_VALID(0), + REG_MRXADDR); + i2c_writel(i2c, 0, REG_MRXRADDR); + } else { + i2c->mode = REG_CON_MOD_TX; + } + + i2c->msg = &msgs[0]; + + ret = 1; + } + + i2c->addr = msgs[0].addr; + i2c->busy = true; + i2c->state = STATE_START; + i2c->processed = 0; + i2c->error = 0; + + rk3x_i2c_clean_ipd(i2c); + + return ret; +} + +static int rk3x_i2c_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct rk3x_i2c *i2c = (struct rk3x_i2c *)adap->algo_data; + unsigned long timeout, flags; + int ret = 0; + int i; + + spin_lock_irqsave(&i2c->lock, flags); + + clk_enable(i2c->clk); + + /* The clock rate might have changed, so setup the divider again */ + rk3x_i2c_set_scl_rate(i2c, i2c->scl_frequency); + + i2c->is_last_msg = false; + + /* + * Process msgs. We can handle more than one message at once (see + * rk3x_i2c_setup()). + */ + for (i = 0; i < num; i += ret) { + ret = rk3x_i2c_setup(i2c, msgs + i, num - i); + + if (ret < 0) { + dev_err(i2c->dev, "rk3x_i2c_setup() failed\n"); + break; + } + + if (i + ret >= num) + i2c->is_last_msg = true; + + spin_unlock_irqrestore(&i2c->lock, flags); + + rk3x_i2c_start(i2c); + + timeout = wait_event_timeout(i2c->wait, !i2c->busy, + msecs_to_jiffies(WAIT_TIMEOUT)); + + spin_lock_irqsave(&i2c->lock, flags); + + if (timeout == 0) { + dev_err(i2c->dev, "timeout, ipd: 0x%02x, state: %d\n", + i2c_readl(i2c, REG_IPD), i2c->state); + + /* Force a STOP condition without interrupt */ + i2c_writel(i2c, 0, REG_IEN); + i2c_writel(i2c, REG_CON_EN | REG_CON_STOP, REG_CON); + + i2c->state = STATE_IDLE; + + ret = -ETIMEDOUT; + break; + } + + if (i2c->error) { + ret = i2c->error; + break; + } + } + + clk_disable(i2c->clk); + spin_unlock_irqrestore(&i2c->lock, flags); + + return ret; +} + +static u32 rk3x_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; +} + +static const struct i2c_algorithm rk3x_i2c_algorithm = { + .master_xfer = rk3x_i2c_xfer, + .functionality = rk3x_i2c_func, +}; + +static struct rk3x_i2c_soc_data soc_data[3] = { + { .grf_offset = 0x154 }, /* rk3066 */ + { .grf_offset = 0x0a4 }, /* rk3188 */ + { .grf_offset = -1 }, /* no I2C switching needed */ +}; + +static const struct of_device_id rk3x_i2c_match[] = { + { .compatible = "rockchip,rk3066-i2c", .data = (void *)&soc_data[0] }, + { .compatible = "rockchip,rk3188-i2c", .data = (void *)&soc_data[1] }, + { .compatible = "rockchip,rk3288-i2c", .data = (void *)&soc_data[2] }, +}; + +static int rk3x_i2c_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + const struct of_device_id *match; + struct rk3x_i2c *i2c; + struct resource *mem; + int ret = 0; + int bus_nr; + u32 value; + int irq; + + i2c = devm_kzalloc(&pdev->dev, sizeof(struct rk3x_i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + match = of_match_node(rk3x_i2c_match, np); + i2c->soc_data = (struct rk3x_i2c_soc_data *)match->data; + + if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &i2c->scl_frequency)) { + dev_info(&pdev->dev, "using default SCL frequency: %d\n", + DEFAULT_SCL_RATE); + i2c->scl_frequency = DEFAULT_SCL_RATE; + } + + if (i2c->scl_frequency == 0 || i2c->scl_frequency > 400 * 1000) { + dev_warn(&pdev->dev, "invalid SCL frequency specified.\n"); + dev_warn(&pdev->dev, "using default SCL frequency: %d\n", + DEFAULT_SCL_RATE); + i2c->scl_frequency = DEFAULT_SCL_RATE; + } + + strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name)); + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &rk3x_i2c_algorithm; + i2c->adap.retries = 3; + i2c->adap.dev.of_node = np; + i2c->adap.algo_data = i2c; + i2c->adap.dev.parent = &pdev->dev; + + i2c->dev = &pdev->dev; + + spin_lock_init(&i2c->lock); + init_waitqueue_head(&i2c->wait); + + i2c->clk = devm_clk_get(&pdev->dev, 0); + if (IS_ERR(i2c->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + return PTR_ERR(i2c->clk); + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + i2c->regs = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(i2c->regs)) + return PTR_ERR(i2c->regs); + + /* Try to set the I2C adapter number from dt */ + bus_nr = of_alias_get_id(np, "i2c"); + + /* + * Switch to new interface if the SoC also offers the old one. + * The control bit is located in the GRF register space. + */ + if (i2c->soc_data->grf_offset >= 0) { + struct regmap *grf; + + grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf"); + if (IS_ERR(grf)) { + dev_err(&pdev->dev, + "rk3x-i2c needs 'rockchip,grf' property\n"); + return PTR_ERR(grf); + } + + if (bus_nr < 0) { + dev_err(&pdev->dev, "rk3x-i2c needs i2cX alias"); + return -EINVAL; + } + + /* 27+i: write mask, 11+i: value */ + value = BIT(27 + bus_nr) | BIT(11 + bus_nr); + + ret = regmap_write(grf, i2c->soc_data->grf_offset, value); + if (ret != 0) { + dev_err(i2c->dev, "Could not write to GRF: %d\n", ret); + return ret; + } + } + + /* IRQ setup */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "cannot find rk3x IRQ\n"); + return irq; + } + + ret = devm_request_irq(&pdev->dev, irq, rk3x_i2c_irq, + 0, dev_name(&pdev->dev), i2c); + if (ret < 0) { + dev_err(&pdev->dev, "cannot request IRQ\n"); + return ret; + } + + platform_set_drvdata(pdev, i2c); + + ret = clk_prepare(i2c->clk); + if (ret < 0) { + dev_err(&pdev->dev, "Could not prepare clock\n"); + return ret; + } + + ret = i2c_add_adapter(&i2c->adap); + if (ret < 0) { + dev_err(&pdev->dev, "Could not register adapter\n"); + goto err_clk; + } + + dev_info(&pdev->dev, "Initialized RK3xxx I2C bus at 0x%08x\n", + (unsigned int)i2c->regs); + + return 0; + +err_clk: + clk_unprepare(i2c->clk); + return ret; +} + +static int rk3x_i2c_remove(struct platform_device *pdev) +{ + struct rk3x_i2c *i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + clk_unprepare(i2c->clk); + + return 0; +} + +static struct platform_driver rk3x_i2c_driver = { + .probe = rk3x_i2c_probe, + .remove = rk3x_i2c_remove, + .driver = { + .owner = THIS_MODULE, + .name = "rk3x-i2c", + .of_match_table = rk3x_i2c_match, + }, +}; + +module_platform_driver(rk3x_i2c_driver); + +MODULE_DESCRIPTION("Rockchip RK3xxx I2C Bus driver"); +MODULE_AUTHOR("Max Schwarz "); +MODULE_LICENSE("GPL v2"); -- 1.9.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Max Schwarz Subject: [PATCH v5] i2c: add driver for Rockchip RK3xxx SoC I2C adapter Date: Sat, 07 Jun 2014 19:44:43 +0200 Message-ID: <1622583.1BSVBxxgia@typ> References: <5192968.EzcUiXba22@typ> <1956748.HoDAyYWJMb@typ> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1956748.HoDAyYWJMb@typ> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfram Sang Cc: Grant Likely , Rob Herring , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Heiko =?ISO-8859-1?Q?St=FCbner?= , Maxime Ripard , kfx-TNX95d0MmH7DzftRWevZcw@public.gmane.org List-Id: devicetree@vger.kernel.org Driver for the native I2C adapter found in Rockchip RK3xxx SoCs. Configuration is only possible through devicetree. The driver is interrupt driven and supports the I2C_M_IGNORE_NAK mangling bit. Signed-off-by: Max Schwarz --- Sorry for the resend, I forgot to CC the developers at Rockchip, which I promised to do. Patch is unchanged. The driver cannot be used without a proper clock driver supporting rate calculation, such as Heiko St=FCbner's RK3xxx clock driver series [1]. Changes since v4: - fixed a bug in message counting in rk3x_i2c_xfer() - Found/suggested by Wolfram Sang: * fixed style issues * fixed sorting in Kconfig, Makefile * removed unneeded fields from struct rk3x_i2c * REPEATED_START between msgs of one transfer * fixed wrong error code on NAK * support for SMB_QUICK (len =3D=3D 0) * removed unneeded DT check & alias handling * sanity check for clock-frequency Changes since v3: - fixed style issues found by Maxime Ripard - use dt alias id to calculate the bit offset in GRF, as suggested by Maxime Ripard - also use dt alias id for i2c_add_numbered_adapter() Changes since v2: - support for the new GRF syscon mapping by Heiko St=FCbner - probe error handling improvements by Heiko St=FCbner - fixed wrong remove() order found by Heiko St=FCbner - removed unnecessary clk_enable() during probe - removed switch back to old interface during remove Changes since v1: - dt property names "rockchip,*" suggested by Heiko St=FCbner - fixed overly specific RK3188 comment (Heiko St=FCbner) The dts files needed for testing on Radxa Rock are in my tree at https://github.com/xqms/linux.git topic/i2c-rk3x-clean-v4 [1]: http://www.spinics.net/lists/arm-kernel/msg334495.html Documentation/devicetree/bindings/i2c/i2c-rk3x.txt | 42 ++ drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-rk3x.c | 769 +++++++++++++= ++++++++ 4 files changed, 822 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-rk3x.txt create mode 100644 drivers/i2c/busses/i2c-rk3x.c diff --git a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt b/Docum= entation/devicetree/bindings/i2c/i2c-rk3x.txt new file mode 100644 index 0000000..dde6c22 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt @@ -0,0 +1,42 @@ +* Rockchip RK3xxx I2C controller + +This driver interfaces with the native I2C controller present in Rockc= hip +RK3xxx SoCs. + +Required properties : + + - reg : Offset and length of the register set for the device + - compatible : should be "rockchip,rk3066-i2c", "rockchip,rk3188-i2c"= or + "rockchip,rk3288-i2c". + - interrupts : interrupt number + - clocks : parent clock + +Required on RK3066, RK3188 : + + - rockchip,grf : the phandle of the syscon node for the general regis= ter + file (GRF) + - on those SoCs an alias with the correct I2C bus ID (bit offset in t= he GRF) + is also required. + +Optional properties : + + - clock-frequency : SCL frequency to use (in Hz). If omitted, 100kHz = is used. + +Example: + +aliases { + i2c0 =3D &i2c0; +} + +i2c0: i2c@2002d000 { + compatible =3D "rockchip,rk3188-i2c"; + reg =3D <0x2002d000 0x1000>; + interrupts =3D ; + #address-cells =3D <1>; + #size-cells =3D <0>; + + rockchip,grf =3D <&grf>; + + clock-names =3D "i2c"; + clocks =3D <&cru PCLK_I2C0>; +}; diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 7ccc51e..39307d0 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -676,6 +676,16 @@ config I2C_RIIC This driver can also be built as a module. If so, the module will be called i2c-riic. =20 +config I2C_RK3X + tristate "Rockchip RK3xxx I2C adapter" + depends on OF + help + Say Y here to include support for the I2C adapter in Rockchip RK3xx= x + SoCs. + + This driver can also be built as a module. If so, the module will + be called i2c-rk3x. + config HAVE_S3C2410_I2C bool help diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 413d062..5582cf9 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -66,6 +66,7 @@ obj-$(CONFIG_I2C_PXA) +=3D i2c-pxa.o obj-$(CONFIG_I2C_PXA_PCI) +=3D i2c-pxa-pci.o obj-$(CONFIG_I2C_QUP) +=3D i2c-qup.o obj-$(CONFIG_I2C_RIIC) +=3D i2c-riic.o +obj-$(CONFIG_I2C_RK3X) +=3D i2c-rk3x.o obj-$(CONFIG_I2C_S3C2410) +=3D i2c-s3c2410.o obj-$(CONFIG_I2C_S6000) +=3D i2c-s6000.o obj-$(CONFIG_I2C_SH7760) +=3D i2c-sh7760.o diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3= x.c new file mode 100644 index 0000000..7a430f4 --- /dev/null +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -0,0 +1,769 @@ +/* + * Driver for I2C adapter in Rockchip RK3xxx SoC + * + * Max Schwarz + * based on the patches by Rockchip Inc. + * + * This program is free software; you can redistribute it and/or modif= y + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* Register Map */ +#define REG_CON 0x00 /* control register */ +#define REG_CLKDIV 0x04 /* clock divisor register */ +#define REG_MRXADDR 0x08 /* slave address for REGISTER_TX */ +#define REG_MRXRADDR 0x0c /* slave register address for REGISTER_TX = */ +#define REG_MTXCNT 0x10 /* number of bytes to be transmitted */ +#define REG_MRXCNT 0x14 /* number of bytes to be received */ +#define REG_IEN 0x18 /* interrupt enable */ +#define REG_IPD 0x1c /* interrupt pending */ +#define REG_FCNT 0x20 /* finished count */ + +/* Data buffer offsets */ +#define TXBUFFER_BASE 0x100 +#define RXBUFFER_BASE 0x200 + +/* REG_CON bits */ +#define REG_CON_EN BIT(0) +enum { + REG_CON_MOD_TX =3D 0, /* transmit data */ + REG_CON_MOD_REGISTER_TX, /* select register and restart */ + REG_CON_MOD_RX, /* receive data */ + REG_CON_MOD_REGISTER_RX, /* broken: transmits read addr AND writes + * register addr */ +}; +#define REG_CON_MOD(mod) ((mod) << 1) +#define REG_CON_MOD_MASK (BIT(1) | BIT(2)) +#define REG_CON_START BIT(3) +#define REG_CON_STOP BIT(4) +#define REG_CON_LASTACK BIT(5) /* 1: do not send ACK after last rece= ive */ +#define REG_CON_ACTACK BIT(6) /* 1: stop if NACK is received */ + +/* REG_MRXADDR bits */ +#define REG_MRXADDR_VALID(x) BIT(24 + (x)) /* [x*8+7:x*8] of MRX[R]ADD= R valid */ + +/* REG_IEN/REG_IPD bits */ +#define REG_INT_BTF BIT(0) /* a byte was transmitted */ +#define REG_INT_BRF BIT(1) /* a byte was received */ +#define REG_INT_MBTF BIT(2) /* master data transmit finished */ +#define REG_INT_MBRF BIT(3) /* master data receive finished */ +#define REG_INT_START BIT(4) /* START condition generated */ +#define REG_INT_STOP BIT(5) /* STOP condition generated */ +#define REG_INT_NAKRCV BIT(6) /* NACK received */ +#define REG_INT_ALL 0x7f + +/* Constants */ +#define WAIT_TIMEOUT 200 /* ms */ +#define DEFAULT_SCL_RATE (100 * 1000) /* Hz */ + +enum rk3x_i2c_state { + STATE_IDLE, + STATE_START, + STATE_READ, + STATE_WRITE, + STATE_STOP +}; + +/** + * @grf_offset: offset inside the grf regmap for setting the i2c type + */ +struct rk3x_i2c_soc_data { + int grf_offset; +}; + +struct rk3x_i2c { + struct i2c_adapter adap; + struct device *dev; + struct rk3x_i2c_soc_data *soc_data; + + /* Hardware resources */ + void __iomem *regs; + struct clk *clk; + + /* Settings */ + unsigned int scl_frequency; + + /* Synchronization & notification */ + spinlock_t lock; + wait_queue_head_t wait; + bool busy; + + /* Current message */ + struct i2c_msg *msg; + u8 addr; + unsigned int mode; + bool is_last_msg; + + /* I2C state machine */ + enum rk3x_i2c_state state; + unsigned int processed; /* sent/received bytes */ + int error; +}; + +static inline void i2c_writel(struct rk3x_i2c *i2c, u32 value, + unsigned int offset) +{ + writel(value, i2c->regs + offset); +} + +static inline u32 i2c_readl(struct rk3x_i2c *i2c, unsigned int offset) +{ + return readl(i2c->regs + offset); +} + +/* Reset all interrupt pending bits */ +static inline void rk3x_i2c_clean_ipd(struct rk3x_i2c *i2c) +{ + i2c_writel(i2c, REG_INT_ALL, REG_IPD); +} + +/** + * Generate a START condition, which triggers a REG_INT_START interrup= t. + */ +static void rk3x_i2c_start(struct rk3x_i2c *i2c) +{ + u32 val; + + dev_dbg(i2c->dev, "start\n"); + + rk3x_i2c_clean_ipd(i2c); + i2c_writel(i2c, REG_INT_START, REG_IEN); + + /* enable adapter with correct mode, send START condition */ + val =3D REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START; + + /* if we want to react to NACK, set ACTACK bit */ + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) + val |=3D REG_CON_ACTACK; + + i2c_writel(i2c, val, REG_CON); +} + +/** + * Generate a STOP condition, which triggers a REG_INT_STOP interrupt. + * + * @error: Error code to return in rk3x_i2c_xfer + */ +static void rk3x_i2c_stop(struct rk3x_i2c *i2c, int error) +{ + unsigned int ctrl; + + i2c->processed =3D 0; + i2c->msg =3D 0; + i2c->error =3D error; + + if (i2c->is_last_msg) { + /* Enable stop interrupt */ + i2c_writel(i2c, REG_INT_STOP, REG_IEN); + + i2c->state =3D STATE_STOP; + + ctrl =3D i2c_readl(i2c, REG_CON); + ctrl |=3D REG_CON_STOP; + i2c_writel(i2c, ctrl, REG_CON); + } else { + /* Signal rk3x_i2c_xfer to start the next message. */ + i2c->busy =3D 0; + i2c->state =3D STATE_IDLE; + + /* + * The HW is actually not capable of REPEATED START. But we can + * get the intended effect by resetting its internal state + * and issuing an ordinary START. + */ + i2c_writel(i2c, 0, REG_CON); + + /* signal that we are finished with the current msg */ + wake_up(&i2c->wait); + } +} + +/** + * Setup a read according to i2c->msg + */ +static void rk3x_i2c_prepare_read(struct rk3x_i2c *i2c) +{ + unsigned int len =3D i2c->msg->len - i2c->processed; + u32 con; + + con =3D i2c_readl(i2c, REG_CON); + + /* + * The hw can read up to 32 bytes at a time. If we need more than one + * chunk, send an ACK after the last byte of the current chunk. + */ + if (unlikely(len > 32)) { + len =3D 32; + con &=3D ~REG_CON_LASTACK; + } else { + con |=3D REG_CON_LASTACK; + } + + /* make sure we are in plain RX mode if we read a second chunk */ + if (i2c->processed !=3D 0) { + con &=3D ~REG_CON_MOD_MASK; + con |=3D REG_CON_MOD(REG_CON_MOD_RX); + } + + i2c_writel(i2c, con, REG_CON); + i2c_writel(i2c, len, REG_MRXCNT); +} + +/** + * Fill the transmit buffer with data from i2c->msg + */ +static void rk3x_i2c_fill_transmit_buf(struct rk3x_i2c *i2c) +{ + unsigned int i, j; + u32 cnt =3D 0; + u32 val; + u8 byte; + + for (i =3D 0; i < 8; ++i) { + val =3D 0; + for (j =3D 0; j < 4; ++j) { + if (i2c->processed =3D=3D i2c->msg->len) + break; + + if (i2c->processed =3D=3D 0 && cnt =3D=3D 0) + byte =3D (i2c->addr & 0x7f) << 1; + else + byte =3D i2c->msg->buf[i2c->processed++]; + + val |=3D byte << (j * 8); + cnt++; + } + + i2c_writel(i2c, val, TXBUFFER_BASE + 4 * i); + + if (i2c->processed =3D=3D i2c->msg->len) + break; + } + + i2c_writel(i2c, cnt, REG_MTXCNT); +} + + +/* IRQ handlers for individual states */ + +static void rk3x_i2c_handle_start(struct rk3x_i2c *i2c, unsigned int i= pd) +{ + if (!(ipd & REG_INT_START)) { + rk3x_i2c_stop(i2c, -EIO); + dev_warn(i2c->dev, "unexpected irq in START: 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + return; + } + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_START, REG_IPD); + + /* disable start bit */ + i2c_writel(i2c, i2c_readl(i2c, REG_CON) & ~REG_CON_START, REG_CON); + + /* enable appropriate interrupts and transition */ + if (i2c->mode =3D=3D REG_CON_MOD_TX) { + i2c_writel(i2c, REG_INT_MBTF | REG_INT_NAKRCV, REG_IEN); + i2c->state =3D STATE_WRITE; + rk3x_i2c_fill_transmit_buf(i2c); + } else { + /* in any other case, we are going to be reading. */ + i2c_writel(i2c, REG_INT_MBRF | REG_INT_NAKRCV, REG_IEN); + i2c->state =3D STATE_READ; + rk3x_i2c_prepare_read(i2c); + } +} + +static void rk3x_i2c_handle_write(struct rk3x_i2c *i2c, unsigned int i= pd) +{ + if (!(ipd & REG_INT_MBTF)) { + rk3x_i2c_stop(i2c, -EIO); + dev_err(i2c->dev, "unexpected irq in WRITE: 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + return; + } + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_MBTF, REG_IPD); + + /* are we finished? */ + if (i2c->processed =3D=3D i2c->msg->len) + rk3x_i2c_stop(i2c, i2c->error); + else + rk3x_i2c_fill_transmit_buf(i2c); +} + +static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ip= d) +{ + unsigned int i; + unsigned int len =3D i2c->msg->len - i2c->processed; + unsigned int val; + u8 byte; + + /* we only care for MBRF here. */ + if (!(ipd & REG_INT_MBRF)) + return; + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_MBRF, REG_IPD); + + /* read the data from receive buffer */ + for (i =3D 0; i < len; ++i) { + if (i % 4 =3D=3D 0) + val =3D i2c_readl(i2c, RXBUFFER_BASE + (i / 4) * 4); + + byte =3D (val >> ((i % 4) * 8)) & 0xff; + i2c->msg->buf[i2c->processed++] =3D byte; + } + + /* are we finished? */ + if (i2c->processed =3D=3D i2c->msg->len) + rk3x_i2c_stop(i2c, i2c->error); + else + rk3x_i2c_prepare_read(i2c); +} + +static void rk3x_i2c_handle_stop(struct rk3x_i2c *i2c, unsigned int ip= d) +{ + unsigned int con; + + if (!(ipd & REG_INT_STOP)) { + rk3x_i2c_stop(i2c, -EIO); + dev_err(i2c->dev, "unexpected irq in STOP: 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + return; + } + + /* ack interrupt */ + i2c_writel(i2c, REG_INT_STOP, REG_IPD); + + /* disable STOP bit */ + con =3D i2c_readl(i2c, REG_CON); + con &=3D ~REG_CON_STOP; + i2c_writel(i2c, con, REG_CON); + + i2c->busy =3D 0; + i2c->state =3D STATE_IDLE; + + /* signal rk3x_i2c_xfer that we are finished */ + wake_up(&i2c->wait); +} + +static irqreturn_t rk3x_i2c_irq(int irqno, void *dev_id) +{ + struct rk3x_i2c *i2c =3D dev_id; + unsigned int ipd; + + spin_lock(&i2c->lock); + + ipd =3D i2c_readl(i2c, REG_IPD); + if (i2c->state =3D=3D STATE_IDLE) { + dev_warn(i2c->dev, "irq in STATE_IDLE, ipd =3D 0x%x\n", ipd); + rk3x_i2c_clean_ipd(i2c); + goto out; + } + + dev_dbg(i2c->dev, "IRQ: state %d, ipd: %x\n", i2c->state, ipd); + + /* Clean interrupt bits we don't care about */ + ipd &=3D ~(REG_INT_BRF | REG_INT_BTF); + + if (ipd & REG_INT_NAKRCV) { + /* + * We got a NACK in the last operation. Depending on whether + * IGNORE_NAK is set, we have to stop the operation and report + * an error. + */ + i2c_writel(i2c, REG_INT_NAKRCV, REG_IPD); + + ipd &=3D ~REG_INT_NAKRCV; + + if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) + rk3x_i2c_stop(i2c, -ENXIO); + } + + /* is there anything left to handle? */ + if (unlikely(ipd =3D=3D 0)) + goto out; + + switch (i2c->state) { + case STATE_START: + rk3x_i2c_handle_start(i2c, ipd); + break; + case STATE_WRITE: + rk3x_i2c_handle_write(i2c, ipd); + break; + case STATE_READ: + rk3x_i2c_handle_read(i2c, ipd); + break; + case STATE_STOP: + rk3x_i2c_handle_stop(i2c, ipd); + break; + case STATE_IDLE: + break; + } + +out: + spin_unlock(&i2c->lock); + return IRQ_HANDLED; +} + +static void rk3x_i2c_set_scl_rate(struct rk3x_i2c *i2c, unsigned long = scl_rate) +{ + unsigned long i2c_rate =3D clk_get_rate(i2c->clk); + unsigned int div; + + /* SCL rate =3D (clk rate) / (8 * DIV) */ + div =3D DIV_ROUND_UP(i2c_rate, scl_rate * 8); + + /* The lower and upper half of the CLKDIV reg describe the length of + * SCL low & high periods. */ + div =3D DIV_ROUND_UP(div, 2); + + i2c_writel(i2c, (div << 16) | (div & 0xffff), REG_CLKDIV); +} + +/** + * Setup I2C registers for an I2C operation specified by msgs, num. + * + * Must be called with i2c->lock held. + * + * @msgs: I2C msgs to process + * @num: Number of msgs + * + * returns: Number of I2C msgs processed or negative in case of error + */ +static int rk3x_i2c_setup(struct rk3x_i2c *i2c, struct i2c_msg *msgs, = int num) +{ + u32 addr =3D (msgs[0].addr & 0x7f) << 1; + int ret =3D 0; + + /* + * The I2C adapter can issue a small (len < 4) write packet before + * reading. This speeds up SMBus-style register reads. + * The MRXADDR/MRXRADDR hold the slave address and the slave register + * address in this case. + */ + + if (num >=3D 2 && msgs[0].len < 4 + && !(msgs[0].flags & I2C_M_RD) + && (msgs[1].flags & I2C_M_RD)) { + u32 reg_addr =3D 0; + int i; + + dev_dbg(i2c->dev, "Combined write/read from addr 0x%x\n", + addr >> 1); + + /* Fill MRXRADDR with the register address(es) */ + for (i =3D 0; i < msgs[0].len; ++i) { + reg_addr |=3D msgs[0].buf[i] << (i * 8); + reg_addr |=3D REG_MRXADDR_VALID(i); + } + + /* msgs[0] is handled by hw. */ + i2c->msg =3D &msgs[1]; + + i2c->mode =3D REG_CON_MOD_REGISTER_TX; + + i2c_writel(i2c, addr | REG_MRXADDR_VALID(0), REG_MRXADDR); + i2c_writel(i2c, reg_addr, REG_MRXRADDR); + + ret =3D 2; + } else { + /* + * We'll have to do it the boring way and process the msgs + * one-by-one. + */ + + if (msgs[0].flags & I2C_M_RD) { + addr |=3D 1; /* set read bit */ + + /* + * We have to transmit the slave addr first. Use + * MOD_REGISTER_TX for that purpose. + */ + i2c->mode =3D REG_CON_MOD_REGISTER_TX; + i2c_writel(i2c, addr | REG_MRXADDR_VALID(0), + REG_MRXADDR); + i2c_writel(i2c, 0, REG_MRXRADDR); + } else { + i2c->mode =3D REG_CON_MOD_TX; + } + + i2c->msg =3D &msgs[0]; + + ret =3D 1; + } + + i2c->addr =3D msgs[0].addr; + i2c->busy =3D true; + i2c->state =3D STATE_START; + i2c->processed =3D 0; + i2c->error =3D 0; + + rk3x_i2c_clean_ipd(i2c); + + return ret; +} + +static int rk3x_i2c_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct rk3x_i2c *i2c =3D (struct rk3x_i2c *)adap->algo_data; + unsigned long timeout, flags; + int ret =3D 0; + int i; + + spin_lock_irqsave(&i2c->lock, flags); + + clk_enable(i2c->clk); + + /* The clock rate might have changed, so setup the divider again */ + rk3x_i2c_set_scl_rate(i2c, i2c->scl_frequency); + + i2c->is_last_msg =3D false; + + /* + * Process msgs. We can handle more than one message at once (see + * rk3x_i2c_setup()). + */ + for (i =3D 0; i < num; i +=3D ret) { + ret =3D rk3x_i2c_setup(i2c, msgs + i, num - i); + + if (ret < 0) { + dev_err(i2c->dev, "rk3x_i2c_setup() failed\n"); + break; + } + + if (i + ret >=3D num) + i2c->is_last_msg =3D true; + + spin_unlock_irqrestore(&i2c->lock, flags); + + rk3x_i2c_start(i2c); + + timeout =3D wait_event_timeout(i2c->wait, !i2c->busy, + msecs_to_jiffies(WAIT_TIMEOUT)); + + spin_lock_irqsave(&i2c->lock, flags); + + if (timeout =3D=3D 0) { + dev_err(i2c->dev, "timeout, ipd: 0x%02x, state: %d\n", + i2c_readl(i2c, REG_IPD), i2c->state); + + /* Force a STOP condition without interrupt */ + i2c_writel(i2c, 0, REG_IEN); + i2c_writel(i2c, REG_CON_EN | REG_CON_STOP, REG_CON); + + i2c->state =3D STATE_IDLE; + + ret =3D -ETIMEDOUT; + break; + } + + if (i2c->error) { + ret =3D i2c->error; + break; + } + } + + clk_disable(i2c->clk); + spin_unlock_irqrestore(&i2c->lock, flags); + + return ret; +} + +static u32 rk3x_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLIN= G; +} + +static const struct i2c_algorithm rk3x_i2c_algorithm =3D { + .master_xfer =3D rk3x_i2c_xfer, + .functionality =3D rk3x_i2c_func, +}; + +static struct rk3x_i2c_soc_data soc_data[3] =3D { + { .grf_offset =3D 0x154 }, /* rk3066 */ + { .grf_offset =3D 0x0a4 }, /* rk3188 */ + { .grf_offset =3D -1 }, /* no I2C switching needed */ +}; + +static const struct of_device_id rk3x_i2c_match[] =3D { + { .compatible =3D "rockchip,rk3066-i2c", .data =3D (void *)&soc_data[= 0] }, + { .compatible =3D "rockchip,rk3188-i2c", .data =3D (void *)&soc_data[= 1] }, + { .compatible =3D "rockchip,rk3288-i2c", .data =3D (void *)&soc_data[= 2] }, +}; + +static int rk3x_i2c_probe(struct platform_device *pdev) +{ + struct device_node *np =3D pdev->dev.of_node; + const struct of_device_id *match; + struct rk3x_i2c *i2c; + struct resource *mem; + int ret =3D 0; + int bus_nr; + u32 value; + int irq; + + i2c =3D devm_kzalloc(&pdev->dev, sizeof(struct rk3x_i2c), GFP_KERNEL)= ; + if (!i2c) + return -ENOMEM; + + match =3D of_match_node(rk3x_i2c_match, np); + i2c->soc_data =3D (struct rk3x_i2c_soc_data *)match->data; + + if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &i2c->scl_frequency)) { + dev_info(&pdev->dev, "using default SCL frequency: %d\n", + DEFAULT_SCL_RATE); + i2c->scl_frequency =3D DEFAULT_SCL_RATE; + } + + if (i2c->scl_frequency =3D=3D 0 || i2c->scl_frequency > 400 * 1000) { + dev_warn(&pdev->dev, "invalid SCL frequency specified.\n"); + dev_warn(&pdev->dev, "using default SCL frequency: %d\n", + DEFAULT_SCL_RATE); + i2c->scl_frequency =3D DEFAULT_SCL_RATE; + } + + strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name)); + i2c->adap.owner =3D THIS_MODULE; + i2c->adap.algo =3D &rk3x_i2c_algorithm; + i2c->adap.retries =3D 3; + i2c->adap.dev.of_node =3D np; + i2c->adap.algo_data =3D i2c; + i2c->adap.dev.parent =3D &pdev->dev; + + i2c->dev =3D &pdev->dev; + + spin_lock_init(&i2c->lock); + init_waitqueue_head(&i2c->wait); + + i2c->clk =3D devm_clk_get(&pdev->dev, 0); + if (IS_ERR(i2c->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + return PTR_ERR(i2c->clk); + } + + mem =3D platform_get_resource(pdev, IORESOURCE_MEM, 0); + i2c->regs =3D devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(i2c->regs)) + return PTR_ERR(i2c->regs); + + /* Try to set the I2C adapter number from dt */ + bus_nr =3D of_alias_get_id(np, "i2c"); + + /* + * Switch to new interface if the SoC also offers the old one. + * The control bit is located in the GRF register space. + */ + if (i2c->soc_data->grf_offset >=3D 0) { + struct regmap *grf; + + grf =3D syscon_regmap_lookup_by_phandle(np, "rockchip,grf"); + if (IS_ERR(grf)) { + dev_err(&pdev->dev, + "rk3x-i2c needs 'rockchip,grf' property\n"); + return PTR_ERR(grf); + } + + if (bus_nr < 0) { + dev_err(&pdev->dev, "rk3x-i2c needs i2cX alias"); + return -EINVAL; + } + + /* 27+i: write mask, 11+i: value */ + value =3D BIT(27 + bus_nr) | BIT(11 + bus_nr); + + ret =3D regmap_write(grf, i2c->soc_data->grf_offset, value); + if (ret !=3D 0) { + dev_err(i2c->dev, "Could not write to GRF: %d\n", ret); + return ret; + } + } + + /* IRQ setup */ + irq =3D platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "cannot find rk3x IRQ\n"); + return irq; + } + + ret =3D devm_request_irq(&pdev->dev, irq, rk3x_i2c_irq, + 0, dev_name(&pdev->dev), i2c); + if (ret < 0) { + dev_err(&pdev->dev, "cannot request IRQ\n"); + return ret; + } + + platform_set_drvdata(pdev, i2c); + + ret =3D clk_prepare(i2c->clk); + if (ret < 0) { + dev_err(&pdev->dev, "Could not prepare clock\n"); + return ret; + } + + ret =3D i2c_add_adapter(&i2c->adap); + if (ret < 0) { + dev_err(&pdev->dev, "Could not register adapter\n"); + goto err_clk; + } + + dev_info(&pdev->dev, "Initialized RK3xxx I2C bus at 0x%08x\n", + (unsigned int)i2c->regs); + + return 0; + +err_clk: + clk_unprepare(i2c->clk); + return ret; +} + +static int rk3x_i2c_remove(struct platform_device *pdev) +{ + struct rk3x_i2c *i2c =3D platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + clk_unprepare(i2c->clk); + + return 0; +} + +static struct platform_driver rk3x_i2c_driver =3D { + .probe =3D rk3x_i2c_probe, + .remove =3D rk3x_i2c_remove, + .driver =3D { + .owner =3D THIS_MODULE, + .name =3D "rk3x-i2c", + .of_match_table =3D rk3x_i2c_match, + }, +}; + +module_platform_driver(rk3x_i2c_driver); + +MODULE_DESCRIPTION("Rockchip RK3xxx I2C Bus driver"); +MODULE_AUTHOR("Max Schwarz "); +MODULE_LICENSE("GPL v2"); --=20 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html