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linuxdebug/drivers/i2c/busses/i2c-mpc.c

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null pointer error
2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* This is a combined i2c adapter and algorithm driver for the
* MPC107/Tsi107 PowerPC northbridge and processors that include
* the same I2C unit (8240, 8245, 85xx).
*
* Copyright (C) 2003-2004 Humboldt Solutions Ltd, adrian@humboldt.co.uk
* Copyright (C) 2021 Allied Telesis Labs
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/fsl_devices.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <asm/mpc52xx.h>
#include <asm/mpc85xx.h>
#include <sysdev/fsl_soc.h>
#define DRV_NAME "mpc-i2c"
#define MPC_I2C_CLOCK_LEGACY 0
#define MPC_I2C_CLOCK_PRESERVE (~0U)
#define MPC_I2C_FDR 0x04
#define MPC_I2C_CR 0x08
#define MPC_I2C_SR 0x0c
#define MPC_I2C_DR 0x10
#define MPC_I2C_DFSRR 0x14
#define CCR_MEN 0x80
#define CCR_MIEN 0x40
#define CCR_MSTA 0x20
#define CCR_MTX 0x10
#define CCR_TXAK 0x08
#define CCR_RSTA 0x04
#define CCR_RSVD 0x02
#define CSR_MCF 0x80
#define CSR_MAAS 0x40
#define CSR_MBB 0x20
#define CSR_MAL 0x10
#define CSR_SRW 0x04
#define CSR_MIF 0x02
#define CSR_RXAK 0x01
enum mpc_i2c_action {
MPC_I2C_ACTION_START = 1,
MPC_I2C_ACTION_RESTART,
MPC_I2C_ACTION_READ_BEGIN,
MPC_I2C_ACTION_READ_BYTE,
MPC_I2C_ACTION_WRITE,
MPC_I2C_ACTION_STOP,
__MPC_I2C_ACTION_CNT
};
static const char * const action_str[] = {
"invalid",
"start",
"restart",
"read begin",
"read",
"write",
"stop",
};
static_assert(ARRAY_SIZE(action_str) == __MPC_I2C_ACTION_CNT);
struct mpc_i2c {
struct device *dev;
void __iomem *base;
u32 interrupt;
wait_queue_head_t waitq;
spinlock_t lock;
struct i2c_adapter adap;
int irq;
u32 real_clk;
u8 fdr, dfsrr;
struct clk *clk_per;
u32 cntl_bits;
enum mpc_i2c_action action;
struct i2c_msg *msgs;
int num_msgs;
int curr_msg;
u32 byte_posn;
u32 block;
int rc;
int expect_rxack;
bool has_errata_A004447;
};
struct mpc_i2c_divider {
u16 divider;
u16 fdr; /* including dfsrr */
};
struct mpc_i2c_data {
void (*setup)(struct device_node *node, struct mpc_i2c *i2c, u32 clock);
};
static inline void writeccr(struct mpc_i2c *i2c, u32 x)
{
writeb(x, i2c->base + MPC_I2C_CR);
}
/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
* the bus, because it wants to send ACK.
* Following sequence of enabling/disabling and sending start/stop generates
* the 9 pulses, each with a START then ending with STOP, so it's all OK.
*/
static void mpc_i2c_fixup(struct mpc_i2c *i2c)
{
int k;
unsigned long flags;
for (k = 9; k; k--) {
writeccr(i2c, 0);
writeb(0, i2c->base + MPC_I2C_SR); /* clear any status bits */
writeccr(i2c, CCR_MEN | CCR_MSTA); /* START */
readb(i2c->base + MPC_I2C_DR); /* init xfer */
udelay(15); /* let it hit the bus */
local_irq_save(flags); /* should not be delayed further */
writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSTA); /* delay SDA */
readb(i2c->base + MPC_I2C_DR);
if (k != 1)
udelay(5);
local_irq_restore(flags);
}
writeccr(i2c, CCR_MEN); /* Initiate STOP */
readb(i2c->base + MPC_I2C_DR);
udelay(15); /* Let STOP propagate */
writeccr(i2c, 0);
}
static int i2c_mpc_wait_sr(struct mpc_i2c *i2c, int mask)
{
void __iomem *addr = i2c->base + MPC_I2C_SR;
u8 val;
return readb_poll_timeout(addr, val, val & mask, 0, 100);
}
/*
* Workaround for Erratum A004447. From the P2040CE Rev Q
*
* 1. Set up the frequency divider and sampling rate.
* 2. I2CCR - a0h
* 3. Poll for I2CSR[MBB] to get set.
* 4. If I2CSR[MAL] is set (an indication that SDA is stuck low), then go to
* step 5. If MAL is not set, then go to step 13.
* 5. I2CCR - 00h
* 6. I2CCR - 22h
* 7. I2CCR - a2h
* 8. Poll for I2CSR[MBB] to get set.
* 9. Issue read to I2CDR.
* 10. Poll for I2CSR[MIF] to be set.
* 11. I2CCR - 82h
* 12. Workaround complete. Skip the next steps.
* 13. Issue read to I2CDR.
* 14. Poll for I2CSR[MIF] to be set.
* 15. I2CCR - 80h
*/
static void mpc_i2c_fixup_A004447(struct mpc_i2c *i2c)
{
int ret;
u32 val;
writeccr(i2c, CCR_MEN | CCR_MSTA);
ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
if (ret) {
dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
return;
}
val = readb(i2c->base + MPC_I2C_SR);
if (val & CSR_MAL) {
writeccr(i2c, 0x00);
writeccr(i2c, CCR_MSTA | CCR_RSVD);
writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSVD);
ret = i2c_mpc_wait_sr(i2c, CSR_MBB);
if (ret) {
dev_err(i2c->dev, "timeout waiting for CSR_MBB\n");
return;
}
val = readb(i2c->base + MPC_I2C_DR);
ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
if (ret) {
dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
return;
}
writeccr(i2c, CCR_MEN | CCR_RSVD);
} else {
val = readb(i2c->base + MPC_I2C_DR);
ret = i2c_mpc_wait_sr(i2c, CSR_MIF);
if (ret) {
dev_err(i2c->dev, "timeout waiting for CSR_MIF\n");
return;
}
writeccr(i2c, CCR_MEN);
}
}
#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
{20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
{28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
{36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
{52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a},
{68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09},
{96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81},
{128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30},
{176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32},
{240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10},
{320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a},
{448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14},
{640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17},
{1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d},
{1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c},
{2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f},
{4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e},
{7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c},
{10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
};
static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
u32 *real_clk)
{
struct fwnode_handle *fwnode = of_fwnode_handle(node);
const struct mpc_i2c_divider *div = NULL;
unsigned int pvr = mfspr(SPRN_PVR);
u32 divider;
int i;
if (clock == MPC_I2C_CLOCK_LEGACY) {
/* see below - default fdr = 0x3f -> div = 2048 */
*real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / 2048;
return -EINVAL;
}
/* Determine divider value */
divider = mpc5xxx_fwnode_get_bus_frequency(fwnode) / clock;
/*
* We want to choose an FDR/DFSR that generates an I2C bus speed that
* is equal to or lower than the requested speed.
*/
for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_52xx); i++) {
div = &mpc_i2c_dividers_52xx[i];
/* Old MPC5200 rev A CPUs do not support the high bits */
if (div->fdr & 0xc0 && pvr == 0x80822011)
continue;
if (div->divider >= divider)
break;
}
*real_clk = mpc5xxx_fwnode_get_bus_frequency(fwnode) / div->divider;
return (int)div->fdr;
}
static void mpc_i2c_setup_52xx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock)
{
int ret, fdr;
if (clock == MPC_I2C_CLOCK_PRESERVE) {
dev_dbg(i2c->dev, "using fdr %d\n",
readb(i2c->base + MPC_I2C_FDR));
return;
}
ret = mpc_i2c_get_fdr_52xx(node, clock, &i2c->real_clk);
fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
if (ret >= 0)
dev_info(i2c->dev, "clock %u Hz (fdr=%d)\n", i2c->real_clk,
fdr);
}
#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
static void mpc_i2c_setup_52xx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock)
{
}
#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
#ifdef CONFIG_PPC_MPC512x
static void mpc_i2c_setup_512x(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock)
{
struct device_node *node_ctrl;
void __iomem *ctrl;
const u32 *pval;
u32 idx;
/* Enable I2C interrupts for mpc5121 */
node_ctrl = of_find_compatible_node(NULL, NULL,
"fsl,mpc5121-i2c-ctrl");
if (node_ctrl) {
ctrl = of_iomap(node_ctrl, 0);
if (ctrl) {
/* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
pval = of_get_property(node, "reg", NULL);
idx = (*pval & 0xff) / 0x20;
setbits32(ctrl, 1 << (24 + idx * 2));
iounmap(ctrl);
}
of_node_put(node_ctrl);
}
/* The clock setup for the 52xx works also fine for the 512x */
mpc_i2c_setup_52xx(node, i2c, clock);
}
#else /* CONFIG_PPC_MPC512x */
static void mpc_i2c_setup_512x(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock)
{
}
#endif /* CONFIG_PPC_MPC512x */
#ifdef CONFIG_FSL_SOC
static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
{160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
{288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
{416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
{544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105},
{672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106},
{800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107},
{1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07},
{1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a},
{1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b},
{2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e},
{3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133},
{4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136},
{7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115},
{12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b},
{18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e},
{30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d},
{49152, 0x011e}, {61440, 0x011f}
};
static u32 mpc_i2c_get_sec_cfg_8xxx(void)
{
struct device_node *node;
u32 __iomem *reg;
u32 val = 0;
node = of_find_node_by_name(NULL, "global-utilities");
if (node) {
const u32 *prop = of_get_property(node, "reg", NULL);
if (prop) {
/*
* Map and check POR Device Status Register 2
* (PORDEVSR2) at 0xE0014. Note than while MPC8533
* and MPC8544 indicate SEC frequency ratio
* configuration as bit 26 in PORDEVSR2, other MPC8xxx
* parts may store it differently or may not have it
* at all.
*/
reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
if (!reg)
printk(KERN_ERR
"Error: couldn't map PORDEVSR2\n");
else
val = in_be32(reg) & 0x00000020; /* sec-cfg */
iounmap(reg);
}
}
of_node_put(node);
return val;
}
static u32 mpc_i2c_get_prescaler_8xxx(void)
{
/*
* According to the AN2919 all MPC824x have prescaler 1, while MPC83xx
* may have prescaler 1, 2, or 3, depending on the power-on
* configuration.
*/
u32 prescaler = 1;
/* mpc85xx */
if (pvr_version_is(PVR_VER_E500V1) || pvr_version_is(PVR_VER_E500V2)
|| pvr_version_is(PVR_VER_E500MC)
|| pvr_version_is(PVR_VER_E5500)
|| pvr_version_is(PVR_VER_E6500)) {
unsigned int svr = mfspr(SPRN_SVR);
if ((SVR_SOC_VER(svr) == SVR_8540)
|| (SVR_SOC_VER(svr) == SVR_8541)
|| (SVR_SOC_VER(svr) == SVR_8560)
|| (SVR_SOC_VER(svr) == SVR_8555)
|| (SVR_SOC_VER(svr) == SVR_8610))
/* the above 85xx SoCs have prescaler 1 */
prescaler = 1;
else if ((SVR_SOC_VER(svr) == SVR_8533)
|| (SVR_SOC_VER(svr) == SVR_8544))
/* the above 85xx SoCs have prescaler 3 or 2 */
prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
else
/* all the other 85xx have prescaler 2 */
prescaler = 2;
}
return prescaler;
}
static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
u32 *real_clk)
{
const struct mpc_i2c_divider *div = NULL;
u32 prescaler = mpc_i2c_get_prescaler_8xxx();
u32 divider;
int i;
if (clock == MPC_I2C_CLOCK_LEGACY) {
/* see below - default fdr = 0x1031 -> div = 16 * 3072 */
*real_clk = fsl_get_sys_freq() / prescaler / (16 * 3072);
return -EINVAL;
}
divider = fsl_get_sys_freq() / clock / prescaler;
pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
fsl_get_sys_freq(), clock, divider);
/*
* We want to choose an FDR/DFSR that generates an I2C bus speed that
* is equal to or lower than the requested speed.
*/
for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) {
div = &mpc_i2c_dividers_8xxx[i];
if (div->divider >= divider)
break;
}
*real_clk = fsl_get_sys_freq() / prescaler / div->divider;
return (int)div->fdr;
}
static void mpc_i2c_setup_8xxx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock)
{
int ret, fdr;
if (clock == MPC_I2C_CLOCK_PRESERVE) {
dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
readb(i2c->base + MPC_I2C_DFSRR),
readb(i2c->base + MPC_I2C_FDR));
return;
}
ret = mpc_i2c_get_fdr_8xxx(node, clock, &i2c->real_clk);
fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR);
if (ret >= 0)
dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n",
i2c->real_clk, fdr >> 8, fdr & 0xff);
}
#else /* !CONFIG_FSL_SOC */
static void mpc_i2c_setup_8xxx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock)
{
}
#endif /* CONFIG_FSL_SOC */
static void mpc_i2c_finish(struct mpc_i2c *i2c, int rc)
{
i2c->rc = rc;
i2c->block = 0;
i2c->cntl_bits = CCR_MEN;
writeccr(i2c, i2c->cntl_bits);
wake_up(&i2c->waitq);
}
static void mpc_i2c_do_action(struct mpc_i2c *i2c)
{
struct i2c_msg *msg = NULL;
int dir = 0;
int recv_len = 0;
u8 byte;
dev_dbg(i2c->dev, "action = %s\n", action_str[i2c->action]);
i2c->cntl_bits &= ~(CCR_RSTA | CCR_MTX | CCR_TXAK);
if (i2c->action != MPC_I2C_ACTION_STOP) {
msg = &i2c->msgs[i2c->curr_msg];
if (msg->flags & I2C_M_RD)
dir = 1;
if (msg->flags & I2C_M_RECV_LEN)
recv_len = 1;
}
switch (i2c->action) {
case MPC_I2C_ACTION_RESTART:
i2c->cntl_bits |= CCR_RSTA;
fallthrough;
case MPC_I2C_ACTION_START:
i2c->cntl_bits |= CCR_MSTA | CCR_MTX;
writeccr(i2c, i2c->cntl_bits);
writeb((msg->addr << 1) | dir, i2c->base + MPC_I2C_DR);
i2c->expect_rxack = 1;
i2c->action = dir ? MPC_I2C_ACTION_READ_BEGIN : MPC_I2C_ACTION_WRITE;
break;
case MPC_I2C_ACTION_READ_BEGIN:
if (msg->len) {
if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN))
i2c->cntl_bits |= CCR_TXAK;
writeccr(i2c, i2c->cntl_bits);
/* Dummy read */
readb(i2c->base + MPC_I2C_DR);
}
i2c->action = MPC_I2C_ACTION_READ_BYTE;
break;
case MPC_I2C_ACTION_READ_BYTE:
if (i2c->byte_posn || !recv_len) {
/* Generate Tx ACK on next to last byte */
if (i2c->byte_posn == msg->len - 2)
i2c->cntl_bits |= CCR_TXAK;
/* Do not generate stop on last byte */
if (i2c->byte_posn == msg->len - 1)
i2c->cntl_bits |= CCR_MTX;
writeccr(i2c, i2c->cntl_bits);
}
byte = readb(i2c->base + MPC_I2C_DR);
if (i2c->byte_posn == 0 && recv_len) {
if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX) {
mpc_i2c_finish(i2c, -EPROTO);
return;
}
msg->len += byte;
/*
* For block reads, generate Tx ACK here if data length
* is 1 byte (total length is 2 bytes).
*/
if (msg->len == 2) {
i2c->cntl_bits |= CCR_TXAK;
writeccr(i2c, i2c->cntl_bits);
}
}
dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action], byte);
msg->buf[i2c->byte_posn++] = byte;
break;
case MPC_I2C_ACTION_WRITE:
dev_dbg(i2c->dev, "%s %02x\n", action_str[i2c->action],
msg->buf[i2c->byte_posn]);
writeb(msg->buf[i2c->byte_posn++], i2c->base + MPC_I2C_DR);
i2c->expect_rxack = 1;
break;
case MPC_I2C_ACTION_STOP:
mpc_i2c_finish(i2c, 0);
break;
default:
WARN(1, "Unexpected action %d\n", i2c->action);
break;
}
if (msg && msg->len == i2c->byte_posn) {
i2c->curr_msg++;
i2c->byte_posn = 0;
if (i2c->curr_msg == i2c->num_msgs) {
i2c->action = MPC_I2C_ACTION_STOP;
/*
* We don't get another interrupt on read so
* finish the transfer now
*/
if (dir)
mpc_i2c_finish(i2c, 0);
} else {
i2c->action = MPC_I2C_ACTION_RESTART;
}
}
}
static void mpc_i2c_do_intr(struct mpc_i2c *i2c, u8 status)
{
spin_lock(&i2c->lock);
if (!(status & CSR_MCF)) {
dev_dbg(i2c->dev, "unfinished\n");
mpc_i2c_finish(i2c, -EIO);
goto out;
}
if (status & CSR_MAL) {
dev_dbg(i2c->dev, "arbitration lost\n");
mpc_i2c_finish(i2c, -EAGAIN);
goto out;
}
if (i2c->expect_rxack && (status & CSR_RXAK)) {
dev_dbg(i2c->dev, "no Rx ACK\n");
mpc_i2c_finish(i2c, -ENXIO);
goto out;
}
i2c->expect_rxack = 0;
mpc_i2c_do_action(i2c);
out:
spin_unlock(&i2c->lock);
}
static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
{
struct mpc_i2c *i2c = dev_id;
u8 status;
status = readb(i2c->base + MPC_I2C_SR);
if (status & CSR_MIF) {
/* Wait up to 100us for transfer to properly complete */
readb_poll_timeout_atomic(i2c->base + MPC_I2C_SR, status, status & CSR_MCF, 0, 100);
writeb(0, i2c->base + MPC_I2C_SR);
mpc_i2c_do_intr(i2c, status);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int mpc_i2c_wait_for_completion(struct mpc_i2c *i2c)
{
long time_left;
time_left = wait_event_timeout(i2c->waitq, !i2c->block, i2c->adap.timeout);
if (!time_left)
return -ETIMEDOUT;
if (time_left < 0)
return time_left;
return 0;
}
static int mpc_i2c_execute_msg(struct mpc_i2c *i2c)
{
unsigned long orig_jiffies;
unsigned long flags;
int ret;
spin_lock_irqsave(&i2c->lock, flags);
i2c->curr_msg = 0;
i2c->rc = 0;
i2c->byte_posn = 0;
i2c->block = 1;
i2c->action = MPC_I2C_ACTION_START;
i2c->cntl_bits = CCR_MEN | CCR_MIEN;
writeb(0, i2c->base + MPC_I2C_SR);
writeccr(i2c, i2c->cntl_bits);
mpc_i2c_do_action(i2c);
spin_unlock_irqrestore(&i2c->lock, flags);
ret = mpc_i2c_wait_for_completion(i2c);
if (ret)
i2c->rc = ret;
if (i2c->rc == -EIO || i2c->rc == -EAGAIN || i2c->rc == -ETIMEDOUT)
i2c_recover_bus(&i2c->adap);
orig_jiffies = jiffies;
/* Wait until STOP is seen, allow up to 1 s */
while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
if (time_after(jiffies, orig_jiffies + HZ)) {
u8 status = readb(i2c->base + MPC_I2C_SR);
dev_dbg(i2c->dev, "timeout\n");
if ((status & (CSR_MCF | CSR_MBB | CSR_RXAK)) != 0) {
writeb(status & ~CSR_MAL,
i2c->base + MPC_I2C_SR);
i2c_recover_bus(&i2c->adap);
}
return -EIO;
}
cond_resched();
}
return i2c->rc;
}
static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
int rc, ret = num;
struct mpc_i2c *i2c = i2c_get_adapdata(adap);
int i;
dev_dbg(i2c->dev, "num = %d\n", num);
for (i = 0; i < num; i++)
dev_dbg(i2c->dev, " addr = %02x, flags = %02x, len = %d, %*ph\n",
msgs[i].addr, msgs[i].flags, msgs[i].len,
msgs[i].flags & I2C_M_RD ? 0 : msgs[i].len,
msgs[i].buf);
WARN_ON(i2c->msgs != NULL);
i2c->msgs = msgs;
i2c->num_msgs = num;
rc = mpc_i2c_execute_msg(i2c);
if (rc < 0)
ret = rc;
i2c->num_msgs = 0;
i2c->msgs = NULL;
return ret;
}
static u32 mpc_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
| I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
}
static int fsl_i2c_bus_recovery(struct i2c_adapter *adap)
{
struct mpc_i2c *i2c = i2c_get_adapdata(adap);
if (i2c->has_errata_A004447)
mpc_i2c_fixup_A004447(i2c);
else
mpc_i2c_fixup(i2c);
return 0;
}
static const struct i2c_algorithm mpc_algo = {
.master_xfer = mpc_xfer,
.functionality = mpc_functionality,
};
static struct i2c_adapter mpc_ops = {
.owner = THIS_MODULE,
.algo = &mpc_algo,
.timeout = HZ,
};
static struct i2c_bus_recovery_info fsl_i2c_recovery_info = {
.recover_bus = fsl_i2c_bus_recovery,
};
static int fsl_i2c_probe(struct platform_device *op)
{
const struct mpc_i2c_data *data;
struct mpc_i2c *i2c;
const u32 *prop;
u32 clock = MPC_I2C_CLOCK_LEGACY;
int result = 0;
int plen;
struct clk *clk;
int err;
i2c = devm_kzalloc(&op->dev, sizeof(*i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
i2c->dev = &op->dev; /* for debug and error output */
init_waitqueue_head(&i2c->waitq);
spin_lock_init(&i2c->lock);
i2c->base = devm_platform_ioremap_resource(op, 0);
if (IS_ERR(i2c->base))
return PTR_ERR(i2c->base);
i2c->irq = platform_get_irq(op, 0);
if (i2c->irq < 0)
return i2c->irq;
result = devm_request_irq(&op->dev, i2c->irq, mpc_i2c_isr,
IRQF_SHARED, "i2c-mpc", i2c);
if (result < 0) {
dev_err(i2c->dev, "failed to attach interrupt\n");
return result;
}
/*
* enable clock for the I2C peripheral (non fatal),
* keep a reference upon successful allocation
*/
clk = devm_clk_get_optional(&op->dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
err = clk_prepare_enable(clk);
if (err) {
dev_err(&op->dev, "failed to enable clock\n");
return err;
}
i2c->clk_per = clk;
if (of_property_read_bool(op->dev.of_node, "fsl,preserve-clocking")) {
clock = MPC_I2C_CLOCK_PRESERVE;
} else {
prop = of_get_property(op->dev.of_node, "clock-frequency",
&plen);
if (prop && plen == sizeof(u32))
clock = *prop;
}
data = device_get_match_data(&op->dev);
if (data) {
data->setup(op->dev.of_node, i2c, clock);
} else {
/* Backwards compatibility */
if (of_get_property(op->dev.of_node, "dfsrr", NULL))
mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock);
}
prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
if (prop && plen == sizeof(u32)) {
mpc_ops.timeout = *prop * HZ / 1000000;
if (mpc_ops.timeout < 5)
mpc_ops.timeout = 5;
}
dev_info(i2c->dev, "timeout %u us\n", mpc_ops.timeout * 1000000 / HZ);
if (of_property_read_bool(op->dev.of_node, "fsl,i2c-erratum-a004447"))
i2c->has_errata_A004447 = true;
i2c->adap = mpc_ops;
scnprintf(i2c->adap.name, sizeof(i2c->adap.name),
"MPC adapter (%s)", of_node_full_name(op->dev.of_node));
i2c->adap.dev.parent = &op->dev;
i2c->adap.nr = op->id;
i2c->adap.dev.of_node = of_node_get(op->dev.of_node);
i2c->adap.bus_recovery_info = &fsl_i2c_recovery_info;
platform_set_drvdata(op, i2c);
i2c_set_adapdata(&i2c->adap, i2c);
result = i2c_add_numbered_adapter(&i2c->adap);
if (result)
goto fail_add;
return 0;
fail_add:
clk_disable_unprepare(i2c->clk_per);
return result;
};
static int fsl_i2c_remove(struct platform_device *op)
{
struct mpc_i2c *i2c = platform_get_drvdata(op);
i2c_del_adapter(&i2c->adap);
clk_disable_unprepare(i2c->clk_per);
return 0;
};
static int __maybe_unused mpc_i2c_suspend(struct device *dev)
{
struct mpc_i2c *i2c = dev_get_drvdata(dev);
i2c->fdr = readb(i2c->base + MPC_I2C_FDR);
i2c->dfsrr = readb(i2c->base + MPC_I2C_DFSRR);
return 0;
}
static int __maybe_unused mpc_i2c_resume(struct device *dev)
{
struct mpc_i2c *i2c = dev_get_drvdata(dev);
writeb(i2c->fdr, i2c->base + MPC_I2C_FDR);
writeb(i2c->dfsrr, i2c->base + MPC_I2C_DFSRR);
return 0;
}
static SIMPLE_DEV_PM_OPS(mpc_i2c_pm_ops, mpc_i2c_suspend, mpc_i2c_resume);
static const struct mpc_i2c_data mpc_i2c_data_512x = {
.setup = mpc_i2c_setup_512x,
};
static const struct mpc_i2c_data mpc_i2c_data_52xx = {
.setup = mpc_i2c_setup_52xx,
};
static const struct mpc_i2c_data mpc_i2c_data_8313 = {
.setup = mpc_i2c_setup_8xxx,
};
static const struct mpc_i2c_data mpc_i2c_data_8543 = {
.setup = mpc_i2c_setup_8xxx,
};
static const struct mpc_i2c_data mpc_i2c_data_8544 = {
.setup = mpc_i2c_setup_8xxx,
};
static const struct of_device_id mpc_i2c_of_match[] = {
{.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
{.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
{.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
{.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
{.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
{.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
{.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
/* Backward compatibility */
{.compatible = "fsl-i2c", },
{},
};
MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
/* Structure for a device driver */
static struct platform_driver mpc_i2c_driver = {
.probe = fsl_i2c_probe,
.remove = fsl_i2c_remove,
.driver = {
.name = DRV_NAME,
.of_match_table = mpc_i2c_of_match,
.pm = &mpc_i2c_pm_ops,
},
};
module_platform_driver(mpc_i2c_driver);
MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
"MPC824x/83xx/85xx/86xx/512x/52xx processors");
MODULE_LICENSE("GPL");