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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/i2c/busses/i2c-omap.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-omap.c')
-rw-r--r--drivers/i2c/busses/i2c-omap.c1614
1 files changed, 1614 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
new file mode 100644
index 0000000000..58fd6fa3ed
--- /dev/null
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -0,0 +1,1614 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TI OMAP I2C master mode driver
+ *
+ * Copyright (C) 2003 MontaVista Software, Inc.
+ * Copyright (C) 2005 Nokia Corporation
+ * Copyright (C) 2004 - 2007 Texas Instruments.
+ *
+ * Originally written by MontaVista Software, Inc.
+ * Additional contributions by:
+ * Tony Lindgren <tony@atomide.com>
+ * Imre Deak <imre.deak@nokia.com>
+ * Juha Yrjölä <juha.yrjola@solidboot.com>
+ * Syed Khasim <x0khasim@ti.com>
+ * Nishant Menon <nm@ti.com>
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/platform_data/i2c-omap.h>
+#include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
+
+/* I2C controller revisions */
+#define OMAP_I2C_OMAP1_REV_2 0x20
+
+/* I2C controller revisions present on specific hardware */
+#define OMAP_I2C_REV_ON_2430 0x00000036
+#define OMAP_I2C_REV_ON_3430_3530 0x0000003C
+#define OMAP_I2C_REV_ON_3630 0x00000040
+#define OMAP_I2C_REV_ON_4430_PLUS 0x50400002
+
+/* timeout waiting for the controller to respond */
+#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
+
+/* timeout for pm runtime autosuspend */
+#define OMAP_I2C_PM_TIMEOUT 1000 /* ms */
+
+/* timeout for making decision on bus free status */
+#define OMAP_I2C_BUS_FREE_TIMEOUT (msecs_to_jiffies(10))
+
+/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
+enum {
+ OMAP_I2C_REV_REG = 0,
+ OMAP_I2C_IE_REG,
+ OMAP_I2C_STAT_REG,
+ OMAP_I2C_IV_REG,
+ OMAP_I2C_WE_REG,
+ OMAP_I2C_SYSS_REG,
+ OMAP_I2C_BUF_REG,
+ OMAP_I2C_CNT_REG,
+ OMAP_I2C_DATA_REG,
+ OMAP_I2C_SYSC_REG,
+ OMAP_I2C_CON_REG,
+ OMAP_I2C_OA_REG,
+ OMAP_I2C_SA_REG,
+ OMAP_I2C_PSC_REG,
+ OMAP_I2C_SCLL_REG,
+ OMAP_I2C_SCLH_REG,
+ OMAP_I2C_SYSTEST_REG,
+ OMAP_I2C_BUFSTAT_REG,
+ /* only on OMAP4430 */
+ OMAP_I2C_IP_V2_REVNB_LO,
+ OMAP_I2C_IP_V2_REVNB_HI,
+ OMAP_I2C_IP_V2_IRQSTATUS_RAW,
+ OMAP_I2C_IP_V2_IRQENABLE_SET,
+ OMAP_I2C_IP_V2_IRQENABLE_CLR,
+};
+
+/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
+#define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
+#define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */
+#define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
+#define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
+#define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
+#define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */
+#define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
+
+/* I2C Status Register (OMAP_I2C_STAT): */
+#define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
+#define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
+#define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
+#define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
+#define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
+#define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
+#define OMAP_I2C_STAT_BF (1 << 8) /* Bus Free */
+#define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
+#define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
+#define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
+#define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
+#define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
+
+/* I2C WE wakeup enable register */
+#define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */
+#define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */
+#define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/
+#define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */
+#define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */
+#define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */
+#define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */
+#define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */
+#define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */
+#define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */
+
+#define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
+ OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
+ OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
+ OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
+ OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
+
+/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
+#define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
+#define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */
+#define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
+#define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */
+
+/* I2C Configuration Register (OMAP_I2C_CON): */
+#define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
+#define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
+#define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */
+#define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
+#define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
+#define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
+#define OMAP_I2C_CON_XA (1 << 8) /* Expand address */
+#define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */
+#define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */
+#define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */
+
+/* I2C SCL time value when Master */
+#define OMAP_I2C_SCLL_HSSCLL 8
+#define OMAP_I2C_SCLH_HSSCLH 8
+
+/* I2C System Test Register (OMAP_I2C_SYSTEST): */
+#define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */
+#define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */
+#define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */
+#define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */
+/* Functional mode */
+#define OMAP_I2C_SYSTEST_SCL_I_FUNC (1 << 8) /* SCL line input value */
+#define OMAP_I2C_SYSTEST_SCL_O_FUNC (1 << 7) /* SCL line output value */
+#define OMAP_I2C_SYSTEST_SDA_I_FUNC (1 << 6) /* SDA line input value */
+#define OMAP_I2C_SYSTEST_SDA_O_FUNC (1 << 5) /* SDA line output value */
+/* SDA/SCL IO mode */
+#define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */
+#define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */
+#define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */
+#define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */
+
+/* OCP_SYSSTATUS bit definitions */
+#define SYSS_RESETDONE_MASK (1 << 0)
+
+/* OCP_SYSCONFIG bit definitions */
+#define SYSC_CLOCKACTIVITY_MASK (0x3 << 8)
+#define SYSC_SIDLEMODE_MASK (0x3 << 3)
+#define SYSC_ENAWAKEUP_MASK (1 << 2)
+#define SYSC_SOFTRESET_MASK (1 << 1)
+#define SYSC_AUTOIDLE_MASK (1 << 0)
+
+#define SYSC_IDLEMODE_SMART 0x2
+#define SYSC_CLOCKACTIVITY_FCLK 0x2
+
+/* Errata definitions */
+#define I2C_OMAP_ERRATA_I207 (1 << 0)
+#define I2C_OMAP_ERRATA_I462 (1 << 1)
+
+#define OMAP_I2C_IP_V2_INTERRUPTS_MASK 0x6FFF
+
+struct omap_i2c_dev {
+ struct device *dev;
+ void __iomem *base; /* virtual */
+ int irq;
+ int reg_shift; /* bit shift for I2C register addresses */
+ struct completion cmd_complete;
+ struct resource *ioarea;
+ u32 latency; /* maximum mpu wkup latency */
+ void (*set_mpu_wkup_lat)(struct device *dev,
+ long latency);
+ u32 speed; /* Speed of bus in kHz */
+ u32 flags;
+ u16 scheme;
+ u16 cmd_err;
+ u8 *buf;
+ u8 *regs;
+ size_t buf_len;
+ struct i2c_adapter adapter;
+ u8 threshold;
+ u8 fifo_size; /* use as flag and value
+ * fifo_size==0 implies no fifo
+ * if set, should be trsh+1
+ */
+ u32 rev;
+ unsigned b_hw:1; /* bad h/w fixes */
+ unsigned bb_valid:1; /* true when BB-bit reflects
+ * the I2C bus state
+ */
+ unsigned receiver:1; /* true when we're in receiver mode */
+ u16 iestate; /* Saved interrupt register */
+ u16 pscstate;
+ u16 scllstate;
+ u16 sclhstate;
+ u16 syscstate;
+ u16 westate;
+ u16 errata;
+};
+
+static const u8 reg_map_ip_v1[] = {
+ [OMAP_I2C_REV_REG] = 0x00,
+ [OMAP_I2C_IE_REG] = 0x01,
+ [OMAP_I2C_STAT_REG] = 0x02,
+ [OMAP_I2C_IV_REG] = 0x03,
+ [OMAP_I2C_WE_REG] = 0x03,
+ [OMAP_I2C_SYSS_REG] = 0x04,
+ [OMAP_I2C_BUF_REG] = 0x05,
+ [OMAP_I2C_CNT_REG] = 0x06,
+ [OMAP_I2C_DATA_REG] = 0x07,
+ [OMAP_I2C_SYSC_REG] = 0x08,
+ [OMAP_I2C_CON_REG] = 0x09,
+ [OMAP_I2C_OA_REG] = 0x0a,
+ [OMAP_I2C_SA_REG] = 0x0b,
+ [OMAP_I2C_PSC_REG] = 0x0c,
+ [OMAP_I2C_SCLL_REG] = 0x0d,
+ [OMAP_I2C_SCLH_REG] = 0x0e,
+ [OMAP_I2C_SYSTEST_REG] = 0x0f,
+ [OMAP_I2C_BUFSTAT_REG] = 0x10,
+};
+
+static const u8 reg_map_ip_v2[] = {
+ [OMAP_I2C_REV_REG] = 0x04,
+ [OMAP_I2C_IE_REG] = 0x2c,
+ [OMAP_I2C_STAT_REG] = 0x28,
+ [OMAP_I2C_IV_REG] = 0x34,
+ [OMAP_I2C_WE_REG] = 0x34,
+ [OMAP_I2C_SYSS_REG] = 0x90,
+ [OMAP_I2C_BUF_REG] = 0x94,
+ [OMAP_I2C_CNT_REG] = 0x98,
+ [OMAP_I2C_DATA_REG] = 0x9c,
+ [OMAP_I2C_SYSC_REG] = 0x10,
+ [OMAP_I2C_CON_REG] = 0xa4,
+ [OMAP_I2C_OA_REG] = 0xa8,
+ [OMAP_I2C_SA_REG] = 0xac,
+ [OMAP_I2C_PSC_REG] = 0xb0,
+ [OMAP_I2C_SCLL_REG] = 0xb4,
+ [OMAP_I2C_SCLH_REG] = 0xb8,
+ [OMAP_I2C_SYSTEST_REG] = 0xbC,
+ [OMAP_I2C_BUFSTAT_REG] = 0xc0,
+ [OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
+ [OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
+ [OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
+ [OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
+ [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
+};
+
+static int omap_i2c_xfer_data(struct omap_i2c_dev *omap);
+
+static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap,
+ int reg, u16 val)
+{
+ writew_relaxed(val, omap->base +
+ (omap->regs[reg] << omap->reg_shift));
+}
+
+static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *omap, int reg)
+{
+ return readw_relaxed(omap->base +
+ (omap->regs[reg] << omap->reg_shift));
+}
+
+static void __omap_i2c_init(struct omap_i2c_dev *omap)
+{
+
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
+
+ /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
+ omap_i2c_write_reg(omap, OMAP_I2C_PSC_REG, omap->pscstate);
+
+ /* SCL low and high time values */
+ omap_i2c_write_reg(omap, OMAP_I2C_SCLL_REG, omap->scllstate);
+ omap_i2c_write_reg(omap, OMAP_I2C_SCLH_REG, omap->sclhstate);
+ if (omap->rev >= OMAP_I2C_REV_ON_3430_3530)
+ omap_i2c_write_reg(omap, OMAP_I2C_WE_REG, omap->westate);
+
+ /* Take the I2C module out of reset: */
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+
+ /*
+ * NOTE: right after setting CON_EN, STAT_BB could be 0 while the
+ * bus is busy. It will be changed to 1 on the next IP FCLK clock.
+ * udelay(1) will be enough to fix that.
+ */
+
+ /*
+ * Don't write to this register if the IE state is 0 as it can
+ * cause deadlock.
+ */
+ if (omap->iestate)
+ omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, omap->iestate);
+}
+
+static int omap_i2c_reset(struct omap_i2c_dev *omap)
+{
+ unsigned long timeout;
+ u16 sysc;
+
+ if (omap->rev >= OMAP_I2C_OMAP1_REV_2) {
+ sysc = omap_i2c_read_reg(omap, OMAP_I2C_SYSC_REG);
+
+ /* Disable I2C controller before soft reset */
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG,
+ omap_i2c_read_reg(omap, OMAP_I2C_CON_REG) &
+ ~(OMAP_I2C_CON_EN));
+
+ omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
+ /* For some reason we need to set the EN bit before the
+ * reset done bit gets set. */
+ timeout = jiffies + OMAP_I2C_TIMEOUT;
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+ while (!(omap_i2c_read_reg(omap, OMAP_I2C_SYSS_REG) &
+ SYSS_RESETDONE_MASK)) {
+ if (time_after(jiffies, timeout)) {
+ dev_warn(omap->dev, "timeout waiting "
+ "for controller reset\n");
+ return -ETIMEDOUT;
+ }
+ msleep(1);
+ }
+
+ /* SYSC register is cleared by the reset; rewrite it */
+ omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, sysc);
+
+ if (omap->rev > OMAP_I2C_REV_ON_3430_3530) {
+ /* Schedule I2C-bus monitoring on the next transfer */
+ omap->bb_valid = 0;
+ }
+ }
+
+ return 0;
+}
+
+static int omap_i2c_init(struct omap_i2c_dev *omap)
+{
+ u16 psc = 0, scll = 0, sclh = 0;
+ u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
+ unsigned long fclk_rate = 12000000;
+ unsigned long internal_clk = 0;
+ struct clk *fclk;
+ int error;
+
+ if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) {
+ /*
+ * Enabling all wakup sources to stop I2C freezing on
+ * WFI instruction.
+ * REVISIT: Some wkup sources might not be needed.
+ */
+ omap->westate = OMAP_I2C_WE_ALL;
+ }
+
+ if (omap->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
+ /*
+ * The I2C functional clock is the armxor_ck, so there's
+ * no need to get "armxor_ck" separately. Now, if OMAP2420
+ * always returns 12MHz for the functional clock, we can
+ * do this bit unconditionally.
+ */
+ fclk = clk_get(omap->dev, "fck");
+ if (IS_ERR(fclk)) {
+ error = PTR_ERR(fclk);
+ dev_err(omap->dev, "could not get fck: %i\n", error);
+
+ return error;
+ }
+
+ fclk_rate = clk_get_rate(fclk);
+ clk_put(fclk);
+
+ /* TRM for 5912 says the I2C clock must be prescaled to be
+ * between 7 - 12 MHz. The XOR input clock is typically
+ * 12, 13 or 19.2 MHz. So we should have code that produces:
+ *
+ * XOR MHz Divider Prescaler
+ * 12 1 0
+ * 13 2 1
+ * 19.2 2 1
+ */
+ if (fclk_rate > 12000000)
+ psc = fclk_rate / 12000000;
+ }
+
+ if (!(omap->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
+
+ /*
+ * HSI2C controller internal clk rate should be 19.2 Mhz for
+ * HS and for all modes on 2430. On 34xx we can use lower rate
+ * to get longer filter period for better noise suppression.
+ * The filter is iclk (fclk for HS) period.
+ */
+ if (omap->speed > 400 ||
+ omap->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
+ internal_clk = 19200;
+ else if (omap->speed > 100)
+ internal_clk = 9600;
+ else
+ internal_clk = 4000;
+ fclk = clk_get(omap->dev, "fck");
+ if (IS_ERR(fclk)) {
+ error = PTR_ERR(fclk);
+ dev_err(omap->dev, "could not get fck: %i\n", error);
+
+ return error;
+ }
+ fclk_rate = clk_get_rate(fclk) / 1000;
+ clk_put(fclk);
+
+ /* Compute prescaler divisor */
+ psc = fclk_rate / internal_clk;
+ psc = psc - 1;
+
+ /* If configured for High Speed */
+ if (omap->speed > 400) {
+ unsigned long scl;
+
+ /* For first phase of HS mode */
+ scl = internal_clk / 400;
+ fsscll = scl - (scl / 3) - 7;
+ fssclh = (scl / 3) - 5;
+
+ /* For second phase of HS mode */
+ scl = fclk_rate / omap->speed;
+ hsscll = scl - (scl / 3) - 7;
+ hssclh = (scl / 3) - 5;
+ } else if (omap->speed > 100) {
+ unsigned long scl;
+
+ /* Fast mode */
+ scl = internal_clk / omap->speed;
+ fsscll = scl - (scl / 3) - 7;
+ fssclh = (scl / 3) - 5;
+ } else {
+ /* Standard mode */
+ fsscll = internal_clk / (omap->speed * 2) - 7;
+ fssclh = internal_clk / (omap->speed * 2) - 5;
+ }
+ scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
+ sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
+ } else {
+ /* Program desired operating rate */
+ fclk_rate /= (psc + 1) * 1000;
+ if (psc > 2)
+ psc = 2;
+ scll = fclk_rate / (omap->speed * 2) - 7 + psc;
+ sclh = fclk_rate / (omap->speed * 2) - 7 + psc;
+ }
+
+ omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
+ OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
+ OMAP_I2C_IE_AL) | ((omap->fifo_size) ?
+ (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
+
+ omap->pscstate = psc;
+ omap->scllstate = scll;
+ omap->sclhstate = sclh;
+
+ if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) {
+ /* Not implemented */
+ omap->bb_valid = 1;
+ }
+
+ __omap_i2c_init(omap);
+
+ return 0;
+}
+
+/*
+ * Try bus recovery, but only if SDA is actually low.
+ */
+static int omap_i2c_recover_bus(struct omap_i2c_dev *omap)
+{
+ u16 systest;
+
+ systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
+ if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
+ (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC))
+ return 0; /* bus seems to already be fine */
+ if (!(systest & OMAP_I2C_SYSTEST_SCL_I_FUNC))
+ return -EBUSY; /* recovery would not fix SCL */
+ return i2c_recover_bus(&omap->adapter);
+}
+
+/*
+ * Waiting on Bus Busy
+ */
+static int omap_i2c_wait_for_bb(struct omap_i2c_dev *omap)
+{
+ unsigned long timeout;
+
+ timeout = jiffies + OMAP_I2C_TIMEOUT;
+ while (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
+ if (time_after(jiffies, timeout))
+ return omap_i2c_recover_bus(omap);
+ msleep(1);
+ }
+
+ return 0;
+}
+
+/*
+ * Wait while BB-bit doesn't reflect the I2C bus state
+ *
+ * In a multimaster environment, after IP software reset, BB-bit value doesn't
+ * correspond to the current bus state. It may happen what BB-bit will be 0,
+ * while the bus is busy due to another I2C master activity.
+ * Here are BB-bit values after reset:
+ * SDA SCL BB NOTES
+ * 0 0 0 1, 2
+ * 1 0 0 1, 2
+ * 0 1 1
+ * 1 1 0 3
+ * Later, if IP detect SDA=0 and SCL=1 (ACK) or SDA 1->0 while SCL=1 (START)
+ * combinations on the bus, it set BB-bit to 1.
+ * If IP detect SDA 0->1 while SCL=1 (STOP) combination on the bus,
+ * it set BB-bit to 0 and BF to 1.
+ * BB and BF bits correctly tracks the bus state while IP is suspended
+ * BB bit became valid on the next FCLK clock after CON_EN bit set
+ *
+ * NOTES:
+ * 1. Any transfer started when BB=0 and bus is busy wouldn't be
+ * completed by IP and results in controller timeout.
+ * 2. Any transfer started when BB=0 and SCL=0 results in IP
+ * starting to drive SDA low. In that case IP corrupt data
+ * on the bus.
+ * 3. Any transfer started in the middle of another master's transfer
+ * results in unpredictable results and data corruption
+ */
+static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *omap)
+{
+ unsigned long bus_free_timeout = 0;
+ unsigned long timeout;
+ int bus_free = 0;
+ u16 stat, systest;
+
+ if (omap->bb_valid)
+ return 0;
+
+ timeout = jiffies + OMAP_I2C_TIMEOUT;
+ while (1) {
+ stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+ /*
+ * We will see BB or BF event in a case IP had detected any
+ * activity on the I2C bus. Now IP correctly tracks the bus
+ * state. BB-bit value is valid.
+ */
+ if (stat & (OMAP_I2C_STAT_BB | OMAP_I2C_STAT_BF))
+ break;
+
+ /*
+ * Otherwise, we must look signals on the bus to make
+ * the right decision.
+ */
+ systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
+ if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
+ (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) {
+ if (!bus_free) {
+ bus_free_timeout = jiffies +
+ OMAP_I2C_BUS_FREE_TIMEOUT;
+ bus_free = 1;
+ }
+
+ /*
+ * SDA and SCL lines was high for 10 ms without bus
+ * activity detected. The bus is free. Consider
+ * BB-bit value is valid.
+ */
+ if (time_after(jiffies, bus_free_timeout))
+ break;
+ } else {
+ bus_free = 0;
+ }
+
+ if (time_after(jiffies, timeout)) {
+ /*
+ * SDA or SCL were low for the entire timeout without
+ * any activity detected. Most likely, a slave is
+ * locking up the bus with no master driving the clock.
+ */
+ dev_warn(omap->dev, "timeout waiting for bus ready\n");
+ return omap_i2c_recover_bus(omap);
+ }
+
+ msleep(1);
+ }
+
+ omap->bb_valid = 1;
+ return 0;
+}
+
+static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx)
+{
+ u16 buf;
+
+ if (omap->flags & OMAP_I2C_FLAG_NO_FIFO)
+ return;
+
+ /*
+ * Set up notification threshold based on message size. We're doing
+ * this to try and avoid draining feature as much as possible. Whenever
+ * we have big messages to transfer (bigger than our total fifo size)
+ * then we might use draining feature to transfer the remaining bytes.
+ */
+
+ omap->threshold = clamp(size, (u8) 1, omap->fifo_size);
+
+ buf = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
+
+ if (is_rx) {
+ /* Clear RX Threshold */
+ buf &= ~(0x3f << 8);
+ buf |= ((omap->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
+ } else {
+ /* Clear TX Threshold */
+ buf &= ~0x3f;
+ buf |= (omap->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
+ }
+
+ omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, buf);
+
+ if (omap->rev < OMAP_I2C_REV_ON_3630)
+ omap->b_hw = 1; /* Enable hardware fixes */
+
+ /* calculate wakeup latency constraint for MPU */
+ if (omap->set_mpu_wkup_lat != NULL)
+ omap->latency = (1000000 * omap->threshold) /
+ (1000 * omap->speed / 8);
+}
+
+static void omap_i2c_wait(struct omap_i2c_dev *omap)
+{
+ u16 stat;
+ u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+ int count = 0;
+
+ do {
+ stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+ count++;
+ } while (!(stat & mask) && count < 5);
+}
+
+/*
+ * Low level master read/write transaction.
+ */
+static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
+ struct i2c_msg *msg, int stop, bool polling)
+{
+ struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
+ unsigned long timeout;
+ u16 w;
+ int ret;
+
+ dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
+ msg->addr, msg->len, msg->flags, stop);
+
+ omap->receiver = !!(msg->flags & I2C_M_RD);
+ omap_i2c_resize_fifo(omap, msg->len, omap->receiver);
+
+ omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr);
+
+ /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
+ omap->buf = msg->buf;
+ omap->buf_len = msg->len;
+
+ /* make sure writes to omap->buf_len are ordered */
+ barrier();
+
+ omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len);
+
+ /* Clear the FIFO Buffers */
+ w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
+ w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
+ omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w);
+
+ if (!polling)
+ reinit_completion(&omap->cmd_complete);
+ omap->cmd_err = 0;
+
+ w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
+
+ /* High speed configuration */
+ if (omap->speed > 400)
+ w |= OMAP_I2C_CON_OPMODE_HS;
+
+ if (msg->flags & I2C_M_STOP)
+ stop = 1;
+ if (msg->flags & I2C_M_TEN)
+ w |= OMAP_I2C_CON_XA;
+ if (!(msg->flags & I2C_M_RD))
+ w |= OMAP_I2C_CON_TRX;
+
+ if (!omap->b_hw && stop)
+ w |= OMAP_I2C_CON_STP;
+ /*
+ * NOTE: STAT_BB bit could became 1 here if another master occupy
+ * the bus. IP successfully complete transfer when the bus will be
+ * free again (BB reset to 0).
+ */
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
+
+ /*
+ * Don't write stt and stp together on some hardware.
+ */
+ if (omap->b_hw && stop) {
+ unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
+ u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
+ while (con & OMAP_I2C_CON_STT) {
+ con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
+
+ /* Let the user know if i2c is in a bad state */
+ if (time_after(jiffies, delay)) {
+ dev_err(omap->dev, "controller timed out "
+ "waiting for start condition to finish\n");
+ return -ETIMEDOUT;
+ }
+ cpu_relax();
+ }
+
+ w |= OMAP_I2C_CON_STP;
+ w &= ~OMAP_I2C_CON_STT;
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
+ }
+
+ /*
+ * REVISIT: We should abort the transfer on signals, but the bus goes
+ * into arbitration and we're currently unable to recover from it.
+ */
+ if (!polling) {
+ timeout = wait_for_completion_timeout(&omap->cmd_complete,
+ OMAP_I2C_TIMEOUT);
+ } else {
+ do {
+ omap_i2c_wait(omap);
+ ret = omap_i2c_xfer_data(omap);
+ } while (ret == -EAGAIN);
+
+ timeout = !ret;
+ }
+
+ if (timeout == 0) {
+ dev_err(omap->dev, "controller timed out\n");
+ omap_i2c_reset(omap);
+ __omap_i2c_init(omap);
+ return -ETIMEDOUT;
+ }
+
+ if (likely(!omap->cmd_err))
+ return 0;
+
+ /* We have an error */
+ if (omap->cmd_err & (OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) {
+ omap_i2c_reset(omap);
+ __omap_i2c_init(omap);
+ return -EIO;
+ }
+
+ if (omap->cmd_err & OMAP_I2C_STAT_AL)
+ return -EAGAIN;
+
+ if (omap->cmd_err & OMAP_I2C_STAT_NACK) {
+ if (msg->flags & I2C_M_IGNORE_NAK)
+ return 0;
+
+ w = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
+ w |= OMAP_I2C_CON_STP;
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
+ return -EREMOTEIO;
+ }
+ return -EIO;
+}
+
+
+/*
+ * Prepare controller for a transaction and call omap_i2c_xfer_msg
+ * to do the work during IRQ processing.
+ */
+static int
+omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num,
+ bool polling)
+{
+ struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
+ int i;
+ int r;
+
+ r = pm_runtime_get_sync(omap->dev);
+ if (r < 0)
+ goto out;
+
+ r = omap_i2c_wait_for_bb_valid(omap);
+ if (r < 0)
+ goto out;
+
+ r = omap_i2c_wait_for_bb(omap);
+ if (r < 0)
+ goto out;
+
+ if (omap->set_mpu_wkup_lat != NULL)
+ omap->set_mpu_wkup_lat(omap->dev, omap->latency);
+
+ for (i = 0; i < num; i++) {
+ r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)),
+ polling);
+ if (r != 0)
+ break;
+ }
+
+ if (r == 0)
+ r = num;
+
+ omap_i2c_wait_for_bb(omap);
+
+ if (omap->set_mpu_wkup_lat != NULL)
+ omap->set_mpu_wkup_lat(omap->dev, -1);
+
+out:
+ pm_runtime_mark_last_busy(omap->dev);
+ pm_runtime_put_autosuspend(omap->dev);
+ return r;
+}
+
+static int
+omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+ return omap_i2c_xfer_common(adap, msgs, num, false);
+}
+
+static int
+omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+ return omap_i2c_xfer_common(adap, msgs, num, true);
+}
+
+static u32
+omap_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
+ I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+static inline void
+omap_i2c_complete_cmd(struct omap_i2c_dev *omap, u16 err)
+{
+ omap->cmd_err |= err;
+ complete(&omap->cmd_complete);
+}
+
+static inline void
+omap_i2c_ack_stat(struct omap_i2c_dev *omap, u16 stat)
+{
+ omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, stat);
+}
+
+static inline void i2c_omap_errata_i207(struct omap_i2c_dev *omap, u16 stat)
+{
+ /*
+ * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
+ * Not applicable for OMAP4.
+ * Under certain rare conditions, RDR could be set again
+ * when the bus is busy, then ignore the interrupt and
+ * clear the interrupt.
+ */
+ if (stat & OMAP_I2C_STAT_RDR) {
+ /* Step 1: If RDR is set, clear it */
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
+
+ /* Step 2: */
+ if (!(omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
+ & OMAP_I2C_STAT_BB)) {
+
+ /* Step 3: */
+ if (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
+ & OMAP_I2C_STAT_RDR) {
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
+ dev_dbg(omap->dev, "RDR when bus is busy.\n");
+ }
+
+ }
+ }
+}
+
+/* rev1 devices are apparently only on some 15xx */
+#ifdef CONFIG_ARCH_OMAP15XX
+
+static irqreturn_t
+omap_i2c_omap1_isr(int this_irq, void *dev_id)
+{
+ struct omap_i2c_dev *omap = dev_id;
+ u16 iv, w;
+
+ if (pm_runtime_suspended(omap->dev))
+ return IRQ_NONE;
+
+ iv = omap_i2c_read_reg(omap, OMAP_I2C_IV_REG);
+ switch (iv) {
+ case 0x00: /* None */
+ break;
+ case 0x01: /* Arbitration lost */
+ dev_err(omap->dev, "Arbitration lost\n");
+ omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_AL);
+ break;
+ case 0x02: /* No acknowledgement */
+ omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_NACK);
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
+ break;
+ case 0x03: /* Register access ready */
+ omap_i2c_complete_cmd(omap, 0);
+ break;
+ case 0x04: /* Receive data ready */
+ if (omap->buf_len) {
+ w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
+ *omap->buf++ = w;
+ omap->buf_len--;
+ if (omap->buf_len) {
+ *omap->buf++ = w >> 8;
+ omap->buf_len--;
+ }
+ } else
+ dev_err(omap->dev, "RRDY IRQ while no data requested\n");
+ break;
+ case 0x05: /* Transmit data ready */
+ if (omap->buf_len) {
+ w = *omap->buf++;
+ omap->buf_len--;
+ if (omap->buf_len) {
+ w |= *omap->buf++ << 8;
+ omap->buf_len--;
+ }
+ omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
+ } else
+ dev_err(omap->dev, "XRDY IRQ while no data to send\n");
+ break;
+ default:
+ return IRQ_NONE;
+ }
+
+ return IRQ_HANDLED;
+}
+#else
+#define omap_i2c_omap1_isr NULL
+#endif
+
+/*
+ * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing
+ * data to DATA_REG. Otherwise some data bytes can be lost while transferring
+ * them from the memory to the I2C interface.
+ */
+static int errata_omap3_i462(struct omap_i2c_dev *omap)
+{
+ unsigned long timeout = 10000;
+ u16 stat;
+
+ do {
+ stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+ if (stat & OMAP_I2C_STAT_XUDF)
+ break;
+
+ if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
+ omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_XRDY |
+ OMAP_I2C_STAT_XDR));
+ if (stat & OMAP_I2C_STAT_NACK) {
+ omap->cmd_err |= OMAP_I2C_STAT_NACK;
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
+ }
+
+ if (stat & OMAP_I2C_STAT_AL) {
+ dev_err(omap->dev, "Arbitration lost\n");
+ omap->cmd_err |= OMAP_I2C_STAT_AL;
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
+ }
+
+ return -EIO;
+ }
+
+ cpu_relax();
+ } while (--timeout);
+
+ if (!timeout) {
+ dev_err(omap->dev, "timeout waiting on XUDF bit\n");
+ return 0;
+ }
+
+ return 0;
+}
+
+static void omap_i2c_receive_data(struct omap_i2c_dev *omap, u8 num_bytes,
+ bool is_rdr)
+{
+ u16 w;
+
+ while (num_bytes--) {
+ w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
+ *omap->buf++ = w;
+ omap->buf_len--;
+
+ /*
+ * Data reg in 2430, omap3 and
+ * omap4 is 8 bit wide
+ */
+ if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
+ *omap->buf++ = w >> 8;
+ omap->buf_len--;
+ }
+ }
+}
+
+static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes,
+ bool is_xdr)
+{
+ u16 w;
+
+ while (num_bytes--) {
+ w = *omap->buf++;
+ omap->buf_len--;
+
+ /*
+ * Data reg in 2430, omap3 and
+ * omap4 is 8 bit wide
+ */
+ if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
+ w |= *omap->buf++ << 8;
+ omap->buf_len--;
+ }
+
+ if (omap->errata & I2C_OMAP_ERRATA_I462) {
+ int ret;
+
+ ret = errata_omap3_i462(omap);
+ if (ret < 0)
+ return ret;
+ }
+
+ omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
+ }
+
+ return 0;
+}
+
+static irqreturn_t
+omap_i2c_isr(int irq, void *dev_id)
+{
+ struct omap_i2c_dev *omap = dev_id;
+ irqreturn_t ret = IRQ_HANDLED;
+ u16 mask;
+ u16 stat;
+
+ stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+ mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG) & ~OMAP_I2C_STAT_NACK;
+
+ if (stat & mask)
+ ret = IRQ_WAKE_THREAD;
+
+ return ret;
+}
+
+static int omap_i2c_xfer_data(struct omap_i2c_dev *omap)
+{
+ u16 bits;
+ u16 stat;
+ int err = 0, count = 0;
+
+ do {
+ bits = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+ stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+ stat &= bits;
+
+ /* If we're in receiver mode, ignore XDR/XRDY */
+ if (omap->receiver)
+ stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
+ else
+ stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
+
+ if (!stat) {
+ /* my work here is done */
+ err = -EAGAIN;
+ break;
+ }
+
+ dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat);
+ if (count++ == 100) {
+ dev_warn(omap->dev, "Too much work in one IRQ\n");
+ break;
+ }
+
+ if (stat & OMAP_I2C_STAT_NACK) {
+ err |= OMAP_I2C_STAT_NACK;
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
+ }
+
+ if (stat & OMAP_I2C_STAT_AL) {
+ dev_err(omap->dev, "Arbitration lost\n");
+ err |= OMAP_I2C_STAT_AL;
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
+ }
+
+ /*
+ * ProDB0017052: Clear ARDY bit twice
+ */
+ if (stat & OMAP_I2C_STAT_ARDY)
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ARDY);
+
+ if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
+ OMAP_I2C_STAT_AL)) {
+ omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_RRDY |
+ OMAP_I2C_STAT_RDR |
+ OMAP_I2C_STAT_XRDY |
+ OMAP_I2C_STAT_XDR |
+ OMAP_I2C_STAT_ARDY));
+ break;
+ }
+
+ if (stat & OMAP_I2C_STAT_RDR) {
+ u8 num_bytes = 1;
+
+ if (omap->fifo_size)
+ num_bytes = omap->buf_len;
+
+ if (omap->errata & I2C_OMAP_ERRATA_I207) {
+ i2c_omap_errata_i207(omap, stat);
+ num_bytes = (omap_i2c_read_reg(omap,
+ OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F;
+ }
+
+ omap_i2c_receive_data(omap, num_bytes, true);
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
+ continue;
+ }
+
+ if (stat & OMAP_I2C_STAT_RRDY) {
+ u8 num_bytes = 1;
+
+ if (omap->threshold)
+ num_bytes = omap->threshold;
+
+ omap_i2c_receive_data(omap, num_bytes, false);
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RRDY);
+ continue;
+ }
+
+ if (stat & OMAP_I2C_STAT_XDR) {
+ u8 num_bytes = 1;
+ int ret;
+
+ if (omap->fifo_size)
+ num_bytes = omap->buf_len;
+
+ ret = omap_i2c_transmit_data(omap, num_bytes, true);
+ if (ret < 0)
+ break;
+
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XDR);
+ continue;
+ }
+
+ if (stat & OMAP_I2C_STAT_XRDY) {
+ u8 num_bytes = 1;
+ int ret;
+
+ if (omap->threshold)
+ num_bytes = omap->threshold;
+
+ ret = omap_i2c_transmit_data(omap, num_bytes, false);
+ if (ret < 0)
+ break;
+
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XRDY);
+ continue;
+ }
+
+ if (stat & OMAP_I2C_STAT_ROVR) {
+ dev_err(omap->dev, "Receive overrun\n");
+ err |= OMAP_I2C_STAT_ROVR;
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ROVR);
+ break;
+ }
+
+ if (stat & OMAP_I2C_STAT_XUDF) {
+ dev_err(omap->dev, "Transmit underflow\n");
+ err |= OMAP_I2C_STAT_XUDF;
+ omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XUDF);
+ break;
+ }
+ } while (stat);
+
+ return err;
+}
+
+static irqreturn_t
+omap_i2c_isr_thread(int this_irq, void *dev_id)
+{
+ int ret;
+ struct omap_i2c_dev *omap = dev_id;
+
+ ret = omap_i2c_xfer_data(omap);
+ if (ret != -EAGAIN)
+ omap_i2c_complete_cmd(omap, ret);
+
+ return IRQ_HANDLED;
+}
+
+static const struct i2c_algorithm omap_i2c_algo = {
+ .master_xfer = omap_i2c_xfer_irq,
+ .master_xfer_atomic = omap_i2c_xfer_polling,
+ .functionality = omap_i2c_func,
+};
+
+static const struct i2c_adapter_quirks omap_i2c_quirks = {
+ .flags = I2C_AQ_NO_ZERO_LEN,
+};
+
+#ifdef CONFIG_OF
+static struct omap_i2c_bus_platform_data omap2420_pdata = {
+ .rev = OMAP_I2C_IP_VERSION_1,
+ .flags = OMAP_I2C_FLAG_NO_FIFO |
+ OMAP_I2C_FLAG_SIMPLE_CLOCK |
+ OMAP_I2C_FLAG_16BIT_DATA_REG |
+ OMAP_I2C_FLAG_BUS_SHIFT_2,
+};
+
+static struct omap_i2c_bus_platform_data omap2430_pdata = {
+ .rev = OMAP_I2C_IP_VERSION_1,
+ .flags = OMAP_I2C_FLAG_BUS_SHIFT_2 |
+ OMAP_I2C_FLAG_FORCE_19200_INT_CLK,
+};
+
+static struct omap_i2c_bus_platform_data omap3_pdata = {
+ .rev = OMAP_I2C_IP_VERSION_1,
+ .flags = OMAP_I2C_FLAG_BUS_SHIFT_2,
+};
+
+static struct omap_i2c_bus_platform_data omap4_pdata = {
+ .rev = OMAP_I2C_IP_VERSION_2,
+};
+
+static const struct of_device_id omap_i2c_of_match[] = {
+ {
+ .compatible = "ti,omap4-i2c",
+ .data = &omap4_pdata,
+ },
+ {
+ .compatible = "ti,omap3-i2c",
+ .data = &omap3_pdata,
+ },
+ {
+ .compatible = "ti,omap2430-i2c",
+ .data = &omap2430_pdata,
+ },
+ {
+ .compatible = "ti,omap2420-i2c",
+ .data = &omap2420_pdata,
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
+#endif
+
+#define OMAP_I2C_SCHEME(rev) ((rev & 0xc000) >> 14)
+
+#define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4)
+#define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf)
+
+#define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7)
+#define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f)
+#define OMAP_I2C_SCHEME_0 0
+#define OMAP_I2C_SCHEME_1 1
+
+static int omap_i2c_get_scl(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+ return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;
+}
+
+static int omap_i2c_get_sda(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+ return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;
+}
+
+static void omap_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+ if (val)
+ reg |= OMAP_I2C_SYSTEST_SCL_O;
+ else
+ reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+ omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+ /* enable test mode */
+ reg |= OMAP_I2C_SYSTEST_ST_EN;
+ /* select SDA/SCL IO mode */
+ reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT;
+ /* set SCL to high-impedance state (reset value is 0) */
+ reg |= OMAP_I2C_SYSTEST_SCL_O;
+ /* set SDA to high-impedance state (reset value is 0) */
+ reg |= OMAP_I2C_SYSTEST_SDA_O;
+ omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ u32 reg;
+
+ reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+ /* restore reset values */
+ reg &= ~OMAP_I2C_SYSTEST_ST_EN;
+ reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK;
+ reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+ reg &= ~OMAP_I2C_SYSTEST_SDA_O;
+ omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {
+ .get_scl = omap_i2c_get_scl,
+ .get_sda = omap_i2c_get_sda,
+ .set_scl = omap_i2c_set_scl,
+ .prepare_recovery = omap_i2c_prepare_recovery,
+ .unprepare_recovery = omap_i2c_unprepare_recovery,
+ .recover_bus = i2c_generic_scl_recovery,
+};
+
+static int
+omap_i2c_probe(struct platform_device *pdev)
+{
+ struct omap_i2c_dev *omap;
+ struct i2c_adapter *adap;
+ const struct omap_i2c_bus_platform_data *pdata =
+ dev_get_platdata(&pdev->dev);
+ struct device_node *node = pdev->dev.of_node;
+ const struct of_device_id *match;
+ int irq;
+ int r;
+ u32 rev;
+ u16 minor, major;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ omap = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
+ if (!omap)
+ return -ENOMEM;
+
+ omap->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(omap->base))
+ return PTR_ERR(omap->base);
+
+ match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
+ if (match) {
+ u32 freq = I2C_MAX_STANDARD_MODE_FREQ;
+
+ pdata = match->data;
+ omap->flags = pdata->flags;
+
+ of_property_read_u32(node, "clock-frequency", &freq);
+ /* convert DT freq value in Hz into kHz for speed */
+ omap->speed = freq / 1000;
+ } else if (pdata != NULL) {
+ omap->speed = pdata->clkrate;
+ omap->flags = pdata->flags;
+ omap->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
+ }
+
+ omap->dev = &pdev->dev;
+ omap->irq = irq;
+
+ platform_set_drvdata(pdev, omap);
+ init_completion(&omap->cmd_complete);
+
+ omap->reg_shift = (omap->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
+
+ pm_runtime_enable(omap->dev);
+ pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
+ pm_runtime_use_autosuspend(omap->dev);
+
+ r = pm_runtime_resume_and_get(omap->dev);
+ if (r < 0)
+ goto err_disable_pm;
+
+ /*
+ * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
+ * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset.
+ * Also since the omap_i2c_read_reg uses reg_map_ip_* a
+ * readw_relaxed is done.
+ */
+ rev = readw_relaxed(omap->base + 0x04);
+
+ omap->scheme = OMAP_I2C_SCHEME(rev);
+ switch (omap->scheme) {
+ case OMAP_I2C_SCHEME_0:
+ omap->regs = (u8 *)reg_map_ip_v1;
+ omap->rev = omap_i2c_read_reg(omap, OMAP_I2C_REV_REG);
+ minor = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
+ major = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
+ break;
+ case OMAP_I2C_SCHEME_1:
+ default:
+ omap->regs = (u8 *)reg_map_ip_v2;
+ rev = (rev << 16) |
+ omap_i2c_read_reg(omap, OMAP_I2C_IP_V2_REVNB_LO);
+ minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev);
+ major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev);
+ omap->rev = rev;
+ }
+
+ omap->errata = 0;
+
+ if (omap->rev >= OMAP_I2C_REV_ON_2430 &&
+ omap->rev < OMAP_I2C_REV_ON_4430_PLUS)
+ omap->errata |= I2C_OMAP_ERRATA_I207;
+
+ if (omap->rev <= OMAP_I2C_REV_ON_3430_3530)
+ omap->errata |= I2C_OMAP_ERRATA_I462;
+
+ if (!(omap->flags & OMAP_I2C_FLAG_NO_FIFO)) {
+ u16 s;
+
+ /* Set up the fifo size - Get total size */
+ s = (omap_i2c_read_reg(omap, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
+ omap->fifo_size = 0x8 << s;
+
+ /*
+ * Set up notification threshold as half the total available
+ * size. This is to ensure that we can handle the status on int
+ * call back latencies.
+ */
+
+ omap->fifo_size = (omap->fifo_size / 2);
+
+ if (omap->rev < OMAP_I2C_REV_ON_3630)
+ omap->b_hw = 1; /* Enable hardware fixes */
+
+ /* calculate wakeup latency constraint for MPU */
+ if (omap->set_mpu_wkup_lat != NULL)
+ omap->latency = (1000000 * omap->fifo_size) /
+ (1000 * omap->speed / 8);
+ }
+
+ /* reset ASAP, clearing any IRQs */
+ omap_i2c_init(omap);
+
+ if (omap->rev < OMAP_I2C_OMAP1_REV_2)
+ r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr,
+ IRQF_NO_SUSPEND, pdev->name, omap);
+ else
+ r = devm_request_threaded_irq(&pdev->dev, omap->irq,
+ omap_i2c_isr, omap_i2c_isr_thread,
+ IRQF_NO_SUSPEND | IRQF_ONESHOT,
+ pdev->name, omap);
+
+ if (r) {
+ dev_err(omap->dev, "failure requesting irq %i\n", omap->irq);
+ goto err_unuse_clocks;
+ }
+
+ adap = &omap->adapter;
+ i2c_set_adapdata(adap, omap);
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_DEPRECATED;
+ strscpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
+ adap->algo = &omap_i2c_algo;
+ adap->quirks = &omap_i2c_quirks;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+ adap->bus_recovery_info = &omap_i2c_bus_recovery_info;
+
+ /* i2c device drivers may be active on return from add_adapter() */
+ adap->nr = pdev->id;
+ r = i2c_add_numbered_adapter(adap);
+ if (r)
+ goto err_unuse_clocks;
+
+ dev_info(omap->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr,
+ major, minor, omap->speed);
+
+ pm_runtime_mark_last_busy(omap->dev);
+ pm_runtime_put_autosuspend(omap->dev);
+
+ return 0;
+
+err_unuse_clocks:
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
+ pm_runtime_dont_use_autosuspend(omap->dev);
+ pm_runtime_put_sync(omap->dev);
+err_disable_pm:
+ pm_runtime_disable(&pdev->dev);
+
+ return r;
+}
+
+static void omap_i2c_remove(struct platform_device *pdev)
+{
+ struct omap_i2c_dev *omap = platform_get_drvdata(pdev);
+ int ret;
+
+ i2c_del_adapter(&omap->adapter);
+
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0)
+ dev_err(omap->dev, "Failed to resume hardware, skip disable\n");
+ else
+ omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
+
+ pm_runtime_dont_use_autosuspend(&pdev->dev);
+ pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+}
+
+static int __maybe_unused omap_i2c_runtime_suspend(struct device *dev)
+{
+ struct omap_i2c_dev *omap = dev_get_drvdata(dev);
+
+ omap->iestate = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+
+ if (omap->scheme == OMAP_I2C_SCHEME_0)
+ omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, 0);
+ else
+ omap_i2c_write_reg(omap, OMAP_I2C_IP_V2_IRQENABLE_CLR,
+ OMAP_I2C_IP_V2_INTERRUPTS_MASK);
+
+ if (omap->rev < OMAP_I2C_OMAP1_REV_2) {
+ omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); /* Read clears */
+ } else {
+ omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, omap->iestate);
+
+ /* Flush posted write */
+ omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+ }
+
+ pinctrl_pm_select_sleep_state(dev);
+
+ return 0;
+}
+
+static int __maybe_unused omap_i2c_runtime_resume(struct device *dev)
+{
+ struct omap_i2c_dev *omap = dev_get_drvdata(dev);
+
+ pinctrl_pm_select_default_state(dev);
+
+ if (!omap->regs)
+ return 0;
+
+ __omap_i2c_init(omap);
+
+ return 0;
+}
+
+static const struct dev_pm_ops omap_i2c_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
+ SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
+ omap_i2c_runtime_resume, NULL)
+};
+
+static struct platform_driver omap_i2c_driver = {
+ .probe = omap_i2c_probe,
+ .remove_new = omap_i2c_remove,
+ .driver = {
+ .name = "omap_i2c",
+ .pm = &omap_i2c_pm_ops,
+ .of_match_table = of_match_ptr(omap_i2c_of_match),
+ },
+};
+
+/* I2C may be needed to bring up other drivers */
+static int __init
+omap_i2c_init_driver(void)
+{
+ return platform_driver_register(&omap_i2c_driver);
+}
+subsys_initcall(omap_i2c_init_driver);
+
+static void __exit omap_i2c_exit_driver(void)
+{
+ platform_driver_unregister(&omap_i2c_driver);
+}
+module_exit(omap_i2c_exit_driver);
+
+MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
+MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:omap_i2c");