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-rw-r--r--drivers/i2c/busses/i2c-mpc.c974
1 files changed, 974 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
new file mode 100644
index 0000000000..e4e4995ab2
--- /dev/null
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -0,0 +1,974 @@
+// 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.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.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;
+ 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) {
+ u64 addr;
+ /* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
+ of_property_read_reg(node, 0, &addr, NULL);
+ idx = (addr & 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,
+};
+
+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;
+ struct clk *clk;
+ int result;
+ u32 clock;
+ 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 {
+ result = of_property_read_u32(op->dev.of_node,
+ "clock-frequency", &clock);
+ if (result)
+ clock = MPC_I2C_CLOCK_LEGACY;
+ }
+
+ data = device_get_match_data(&op->dev);
+ if (data) {
+ data->setup(op->dev.of_node, i2c, clock);
+ } else {
+ /* Backwards compatibility */
+ if (of_property_read_bool(op->dev.of_node, "dfsrr"))
+ mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock);
+ }
+
+ /*
+ * "fsl,timeout" has been marked as deprecated and, to maintain
+ * backward compatibility, we will only look for it if
+ * "i2c-scl-clk-low-timeout-us" is not present.
+ */
+ result = of_property_read_u32(op->dev.of_node,
+ "i2c-scl-clk-low-timeout-us",
+ &mpc_ops.timeout);
+ if (result == -EINVAL)
+ result = of_property_read_u32(op->dev.of_node,
+ "fsl,timeout", &mpc_ops.timeout);
+
+ if (!result) {
+ mpc_ops.timeout *= HZ / 1000000;
+ if (mpc_ops.timeout < 5)
+ mpc_ops.timeout = 5;
+ } else {
+ mpc_ops.timeout = HZ;
+ }
+
+ 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 void 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);
+};
+
+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_new = 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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 19:48:20 +0000