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Diffstat (limited to 'drivers/i3c/master/mipi-i3c-hci/pio.c')
-rw-r--r--drivers/i3c/master/mipi-i3c-hci/pio.c1041
1 files changed, 1041 insertions, 0 deletions
diff --git a/drivers/i3c/master/mipi-i3c-hci/pio.c b/drivers/i3c/master/mipi-i3c-hci/pio.c
new file mode 100644
index 000000000..d0272aa93
--- /dev/null
+++ b/drivers/i3c/master/mipi-i3c-hci/pio.c
@@ -0,0 +1,1041 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2020, MIPI Alliance, Inc.
+ *
+ * Author: Nicolas Pitre <npitre@baylibre.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/i3c/master.h>
+#include <linux/io.h>
+
+#include "hci.h"
+#include "cmd.h"
+#include "ibi.h"
+
+
+/*
+ * PIO Access Area
+ */
+
+#define pio_reg_read(r) readl(hci->PIO_regs + (PIO_##r))
+#define pio_reg_write(r, v) writel(v, hci->PIO_regs + (PIO_##r))
+
+#define PIO_COMMAND_QUEUE_PORT 0x00
+#define PIO_RESPONSE_QUEUE_PORT 0x04
+#define PIO_XFER_DATA_PORT 0x08
+#define PIO_IBI_PORT 0x0c
+
+#define PIO_QUEUE_THLD_CTRL 0x10
+#define QUEUE_IBI_STATUS_THLD GENMASK(31, 24)
+#define QUEUE_IBI_DATA_THLD GENMASK(23, 16)
+#define QUEUE_RESP_BUF_THLD GENMASK(15, 8)
+#define QUEUE_CMD_EMPTY_BUF_THLD GENMASK(7, 0)
+
+#define PIO_DATA_BUFFER_THLD_CTRL 0x14
+#define DATA_RX_START_THLD GENMASK(26, 24)
+#define DATA_TX_START_THLD GENMASK(18, 16)
+#define DATA_RX_BUF_THLD GENMASK(10, 8)
+#define DATA_TX_BUF_THLD GENMASK(2, 0)
+
+#define PIO_QUEUE_SIZE 0x18
+#define TX_DATA_BUFFER_SIZE GENMASK(31, 24)
+#define RX_DATA_BUFFER_SIZE GENMASK(23, 16)
+#define IBI_STATUS_SIZE GENMASK(15, 8)
+#define CR_QUEUE_SIZE GENMASK(7, 0)
+
+#define PIO_INTR_STATUS 0x20
+#define PIO_INTR_STATUS_ENABLE 0x24
+#define PIO_INTR_SIGNAL_ENABLE 0x28
+#define PIO_INTR_FORCE 0x2c
+#define STAT_TRANSFER_BLOCKED BIT(25)
+#define STAT_PERR_RESP_UFLOW BIT(24)
+#define STAT_PERR_CMD_OFLOW BIT(23)
+#define STAT_PERR_IBI_UFLOW BIT(22)
+#define STAT_PERR_RX_UFLOW BIT(21)
+#define STAT_PERR_TX_OFLOW BIT(20)
+#define STAT_ERR_RESP_QUEUE_FULL BIT(19)
+#define STAT_WARN_RESP_QUEUE_FULL BIT(18)
+#define STAT_ERR_IBI_QUEUE_FULL BIT(17)
+#define STAT_WARN_IBI_QUEUE_FULL BIT(16)
+#define STAT_ERR_RX_DATA_FULL BIT(15)
+#define STAT_WARN_RX_DATA_FULL BIT(14)
+#define STAT_ERR_TX_DATA_EMPTY BIT(13)
+#define STAT_WARN_TX_DATA_EMPTY BIT(12)
+#define STAT_TRANSFER_ERR BIT(9)
+#define STAT_WARN_INS_STOP_MODE BIT(7)
+#define STAT_TRANSFER_ABORT BIT(5)
+#define STAT_RESP_READY BIT(4)
+#define STAT_CMD_QUEUE_READY BIT(3)
+#define STAT_IBI_STATUS_THLD BIT(2)
+#define STAT_RX_THLD BIT(1)
+#define STAT_TX_THLD BIT(0)
+
+#define PIO_QUEUE_CUR_STATUS 0x38
+#define CUR_IBI_Q_LEVEL GENMASK(28, 20)
+#define CUR_RESP_Q_LEVEL GENMASK(18, 10)
+#define CUR_CMD_Q_EMPTY_LEVEL GENMASK(8, 0)
+
+#define PIO_DATA_BUFFER_CUR_STATUS 0x3c
+#define CUR_RX_BUF_LVL GENMASK(26, 16)
+#define CUR_TX_BUF_LVL GENMASK(10, 0)
+
+/*
+ * Handy status bit combinations
+ */
+
+#define STAT_LATENCY_WARNINGS (STAT_WARN_RESP_QUEUE_FULL | \
+ STAT_WARN_IBI_QUEUE_FULL | \
+ STAT_WARN_RX_DATA_FULL | \
+ STAT_WARN_TX_DATA_EMPTY | \
+ STAT_WARN_INS_STOP_MODE)
+
+#define STAT_LATENCY_ERRORS (STAT_ERR_RESP_QUEUE_FULL | \
+ STAT_ERR_IBI_QUEUE_FULL | \
+ STAT_ERR_RX_DATA_FULL | \
+ STAT_ERR_TX_DATA_EMPTY)
+
+#define STAT_PROG_ERRORS (STAT_TRANSFER_BLOCKED | \
+ STAT_PERR_RESP_UFLOW | \
+ STAT_PERR_CMD_OFLOW | \
+ STAT_PERR_IBI_UFLOW | \
+ STAT_PERR_RX_UFLOW | \
+ STAT_PERR_TX_OFLOW)
+
+#define STAT_ALL_ERRORS (STAT_TRANSFER_ABORT | \
+ STAT_TRANSFER_ERR | \
+ STAT_LATENCY_ERRORS | \
+ STAT_PROG_ERRORS)
+
+struct hci_pio_dev_ibi_data {
+ struct i3c_generic_ibi_pool *pool;
+ unsigned int max_len;
+};
+
+struct hci_pio_ibi_data {
+ struct i3c_ibi_slot *slot;
+ void *data_ptr;
+ unsigned int addr;
+ unsigned int seg_len, seg_cnt;
+ unsigned int max_len;
+ bool last_seg;
+};
+
+struct hci_pio_data {
+ spinlock_t lock;
+ struct hci_xfer *curr_xfer, *xfer_queue;
+ struct hci_xfer *curr_rx, *rx_queue;
+ struct hci_xfer *curr_tx, *tx_queue;
+ struct hci_xfer *curr_resp, *resp_queue;
+ struct hci_pio_ibi_data ibi;
+ unsigned int rx_thresh_size, tx_thresh_size;
+ unsigned int max_ibi_thresh;
+ u32 reg_queue_thresh;
+ u32 enabled_irqs;
+};
+
+static int hci_pio_init(struct i3c_hci *hci)
+{
+ struct hci_pio_data *pio;
+ u32 val, size_val, rx_thresh, tx_thresh, ibi_val;
+
+ pio = kzalloc(sizeof(*pio), GFP_KERNEL);
+ if (!pio)
+ return -ENOMEM;
+
+ hci->io_data = pio;
+ spin_lock_init(&pio->lock);
+
+ size_val = pio_reg_read(QUEUE_SIZE);
+ dev_info(&hci->master.dev, "CMD/RESP FIFO = %ld entries\n",
+ FIELD_GET(CR_QUEUE_SIZE, size_val));
+ dev_info(&hci->master.dev, "IBI FIFO = %ld bytes\n",
+ 4 * FIELD_GET(IBI_STATUS_SIZE, size_val));
+ dev_info(&hci->master.dev, "RX data FIFO = %d bytes\n",
+ 4 * (2 << FIELD_GET(RX_DATA_BUFFER_SIZE, size_val)));
+ dev_info(&hci->master.dev, "TX data FIFO = %d bytes\n",
+ 4 * (2 << FIELD_GET(TX_DATA_BUFFER_SIZE, size_val)));
+
+ /*
+ * Let's initialize data thresholds to half of the actual FIFO size.
+ * The start thresholds aren't used (set to 0) as the FIFO is always
+ * serviced before the corresponding command is queued.
+ */
+ rx_thresh = FIELD_GET(RX_DATA_BUFFER_SIZE, size_val);
+ tx_thresh = FIELD_GET(TX_DATA_BUFFER_SIZE, size_val);
+ if (hci->version_major == 1) {
+ /* those are expressed as 2^[n+1), so just sub 1 if not 0 */
+ if (rx_thresh)
+ rx_thresh -= 1;
+ if (tx_thresh)
+ tx_thresh -= 1;
+ pio->rx_thresh_size = 2 << rx_thresh;
+ pio->tx_thresh_size = 2 << tx_thresh;
+ } else {
+ /* size is 2^(n+1) and threshold is 2^n i.e. already halved */
+ pio->rx_thresh_size = 1 << rx_thresh;
+ pio->tx_thresh_size = 1 << tx_thresh;
+ }
+ val = FIELD_PREP(DATA_RX_BUF_THLD, rx_thresh) |
+ FIELD_PREP(DATA_TX_BUF_THLD, tx_thresh);
+ pio_reg_write(DATA_BUFFER_THLD_CTRL, val);
+
+ /*
+ * Let's raise an interrupt as soon as there is one free cmd slot
+ * or one available response or IBI. For IBI data let's use half the
+ * IBI queue size within allowed bounds.
+ */
+ ibi_val = FIELD_GET(IBI_STATUS_SIZE, size_val);
+ pio->max_ibi_thresh = clamp_val(ibi_val/2, 1, 63);
+ val = FIELD_PREP(QUEUE_IBI_STATUS_THLD, 1) |
+ FIELD_PREP(QUEUE_IBI_DATA_THLD, pio->max_ibi_thresh) |
+ FIELD_PREP(QUEUE_RESP_BUF_THLD, 1) |
+ FIELD_PREP(QUEUE_CMD_EMPTY_BUF_THLD, 1);
+ pio_reg_write(QUEUE_THLD_CTRL, val);
+ pio->reg_queue_thresh = val;
+
+ /* Disable all IRQs but allow all status bits */
+ pio_reg_write(INTR_SIGNAL_ENABLE, 0x0);
+ pio_reg_write(INTR_STATUS_ENABLE, 0xffffffff);
+
+ /* Always accept error interrupts (will be activated on first xfer) */
+ pio->enabled_irqs = STAT_ALL_ERRORS;
+
+ return 0;
+}
+
+static void hci_pio_cleanup(struct i3c_hci *hci)
+{
+ struct hci_pio_data *pio = hci->io_data;
+
+ pio_reg_write(INTR_SIGNAL_ENABLE, 0x0);
+
+ if (pio) {
+ DBG("status = %#x/%#x",
+ pio_reg_read(INTR_STATUS), pio_reg_read(INTR_SIGNAL_ENABLE));
+ BUG_ON(pio->curr_xfer);
+ BUG_ON(pio->curr_rx);
+ BUG_ON(pio->curr_tx);
+ BUG_ON(pio->curr_resp);
+ kfree(pio);
+ hci->io_data = NULL;
+ }
+}
+
+static void hci_pio_write_cmd(struct i3c_hci *hci, struct hci_xfer *xfer)
+{
+ DBG("cmd_desc[%d] = 0x%08x", 0, xfer->cmd_desc[0]);
+ DBG("cmd_desc[%d] = 0x%08x", 1, xfer->cmd_desc[1]);
+ pio_reg_write(COMMAND_QUEUE_PORT, xfer->cmd_desc[0]);
+ pio_reg_write(COMMAND_QUEUE_PORT, xfer->cmd_desc[1]);
+ if (hci->cmd == &mipi_i3c_hci_cmd_v2) {
+ DBG("cmd_desc[%d] = 0x%08x", 2, xfer->cmd_desc[2]);
+ DBG("cmd_desc[%d] = 0x%08x", 3, xfer->cmd_desc[3]);
+ pio_reg_write(COMMAND_QUEUE_PORT, xfer->cmd_desc[2]);
+ pio_reg_write(COMMAND_QUEUE_PORT, xfer->cmd_desc[3]);
+ }
+}
+
+static bool hci_pio_do_rx(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ struct hci_xfer *xfer = pio->curr_rx;
+ unsigned int nr_words;
+ u32 *p;
+
+ p = xfer->data;
+ p += (xfer->data_len - xfer->data_left) / 4;
+
+ while (xfer->data_left >= 4) {
+ /* bail out if FIFO hasn't reached the threshold value yet */
+ if (!(pio_reg_read(INTR_STATUS) & STAT_RX_THLD))
+ return false;
+ nr_words = min(xfer->data_left / 4, pio->rx_thresh_size);
+ /* extract data from FIFO */
+ xfer->data_left -= nr_words * 4;
+ DBG("now %d left %d", nr_words * 4, xfer->data_left);
+ while (nr_words--)
+ *p++ = pio_reg_read(XFER_DATA_PORT);
+ }
+
+ /* trailing data is retrieved upon response reception */
+ return !xfer->data_left;
+}
+
+static void hci_pio_do_trailing_rx(struct i3c_hci *hci,
+ struct hci_pio_data *pio, unsigned int count)
+{
+ struct hci_xfer *xfer = pio->curr_rx;
+ u32 *p;
+
+ DBG("%d remaining", count);
+
+ p = xfer->data;
+ p += (xfer->data_len - xfer->data_left) / 4;
+
+ if (count >= 4) {
+ unsigned int nr_words = count / 4;
+ /* extract data from FIFO */
+ xfer->data_left -= nr_words * 4;
+ DBG("now %d left %d", nr_words * 4, xfer->data_left);
+ while (nr_words--)
+ *p++ = pio_reg_read(XFER_DATA_PORT);
+ }
+
+ count &= 3;
+ if (count) {
+ /*
+ * There are trailing bytes in the last word.
+ * Fetch it and extract bytes in an endian independent way.
+ * Unlike the TX case, we must not write memory past the
+ * end of the destination buffer.
+ */
+ u8 *p_byte = (u8 *)p;
+ u32 data = pio_reg_read(XFER_DATA_PORT);
+
+ xfer->data_word_before_partial = data;
+ xfer->data_left -= count;
+ data = (__force u32) cpu_to_le32(data);
+ while (count--) {
+ *p_byte++ = data;
+ data >>= 8;
+ }
+ }
+}
+
+static bool hci_pio_do_tx(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ struct hci_xfer *xfer = pio->curr_tx;
+ unsigned int nr_words;
+ u32 *p;
+
+ p = xfer->data;
+ p += (xfer->data_len - xfer->data_left) / 4;
+
+ while (xfer->data_left >= 4) {
+ /* bail out if FIFO free space is below set threshold */
+ if (!(pio_reg_read(INTR_STATUS) & STAT_TX_THLD))
+ return false;
+ /* we can fill up to that TX threshold */
+ nr_words = min(xfer->data_left / 4, pio->tx_thresh_size);
+ /* push data into the FIFO */
+ xfer->data_left -= nr_words * 4;
+ DBG("now %d left %d", nr_words * 4, xfer->data_left);
+ while (nr_words--)
+ pio_reg_write(XFER_DATA_PORT, *p++);
+ }
+
+ if (xfer->data_left) {
+ /*
+ * There are trailing bytes to send. We can simply load
+ * them from memory as a word which will keep those bytes
+ * in their proper place even on a BE system. This will
+ * also get some bytes past the actual buffer but no one
+ * should care as they won't be sent out.
+ */
+ if (!(pio_reg_read(INTR_STATUS) & STAT_TX_THLD))
+ return false;
+ DBG("trailing %d", xfer->data_left);
+ pio_reg_write(XFER_DATA_PORT, *p);
+ xfer->data_left = 0;
+ }
+
+ return true;
+}
+
+static bool hci_pio_process_rx(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ while (pio->curr_rx && hci_pio_do_rx(hci, pio))
+ pio->curr_rx = pio->curr_rx->next_data;
+ return !pio->curr_rx;
+}
+
+static bool hci_pio_process_tx(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ while (pio->curr_tx && hci_pio_do_tx(hci, pio))
+ pio->curr_tx = pio->curr_tx->next_data;
+ return !pio->curr_tx;
+}
+
+static void hci_pio_queue_data(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ struct hci_xfer *xfer = pio->curr_xfer;
+ struct hci_xfer *prev_queue_tail;
+
+ if (!xfer->data) {
+ xfer->data_len = xfer->data_left = 0;
+ return;
+ }
+
+ if (xfer->rnw) {
+ prev_queue_tail = pio->rx_queue;
+ pio->rx_queue = xfer;
+ if (pio->curr_rx) {
+ prev_queue_tail->next_data = xfer;
+ } else {
+ pio->curr_rx = xfer;
+ if (!hci_pio_process_rx(hci, pio))
+ pio->enabled_irqs |= STAT_RX_THLD;
+ }
+ } else {
+ prev_queue_tail = pio->tx_queue;
+ pio->tx_queue = xfer;
+ if (pio->curr_tx) {
+ prev_queue_tail->next_data = xfer;
+ } else {
+ pio->curr_tx = xfer;
+ if (!hci_pio_process_tx(hci, pio))
+ pio->enabled_irqs |= STAT_TX_THLD;
+ }
+ }
+}
+
+static void hci_pio_push_to_next_rx(struct i3c_hci *hci, struct hci_xfer *xfer,
+ unsigned int words_to_keep)
+{
+ u32 *from = xfer->data;
+ u32 from_last;
+ unsigned int received, count;
+
+ received = (xfer->data_len - xfer->data_left) / 4;
+ if ((xfer->data_len - xfer->data_left) & 3) {
+ from_last = xfer->data_word_before_partial;
+ received += 1;
+ } else {
+ from_last = from[received];
+ }
+ from += words_to_keep;
+ count = received - words_to_keep;
+
+ while (count) {
+ unsigned int room, left, chunk, bytes_to_move;
+ u32 last_word;
+
+ xfer = xfer->next_data;
+ if (!xfer) {
+ dev_err(&hci->master.dev, "pushing RX data to unexistent xfer\n");
+ return;
+ }
+
+ room = DIV_ROUND_UP(xfer->data_len, 4);
+ left = DIV_ROUND_UP(xfer->data_left, 4);
+ chunk = min(count, room);
+ if (chunk > left) {
+ hci_pio_push_to_next_rx(hci, xfer, chunk - left);
+ left = chunk;
+ xfer->data_left = left * 4;
+ }
+
+ bytes_to_move = xfer->data_len - xfer->data_left;
+ if (bytes_to_move & 3) {
+ /* preserve word to become partial */
+ u32 *p = xfer->data;
+
+ xfer->data_word_before_partial = p[bytes_to_move / 4];
+ }
+ memmove(xfer->data + chunk, xfer->data, bytes_to_move);
+
+ /* treat last word specially because of partial word issues */
+ chunk -= 1;
+
+ memcpy(xfer->data, from, chunk * 4);
+ xfer->data_left -= chunk * 4;
+ from += chunk;
+ count -= chunk;
+
+ last_word = (count == 1) ? from_last : *from++;
+ if (xfer->data_left < 4) {
+ /*
+ * Like in hci_pio_do_trailing_rx(), preserve original
+ * word to be stored partially then store bytes it
+ * in an endian independent way.
+ */
+ u8 *p_byte = xfer->data;
+
+ p_byte += chunk * 4;
+ xfer->data_word_before_partial = last_word;
+ last_word = (__force u32) cpu_to_le32(last_word);
+ while (xfer->data_left--) {
+ *p_byte++ = last_word;
+ last_word >>= 8;
+ }
+ } else {
+ u32 *p = xfer->data;
+
+ p[chunk] = last_word;
+ xfer->data_left -= 4;
+ }
+ count--;
+ }
+}
+
+static void hci_pio_err(struct i3c_hci *hci, struct hci_pio_data *pio,
+ u32 status);
+
+static bool hci_pio_process_resp(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ while (pio->curr_resp &&
+ (pio_reg_read(INTR_STATUS) & STAT_RESP_READY)) {
+ struct hci_xfer *xfer = pio->curr_resp;
+ u32 resp = pio_reg_read(RESPONSE_QUEUE_PORT);
+ unsigned int tid = RESP_TID(resp);
+
+ DBG("resp = 0x%08x", resp);
+ if (tid != xfer->cmd_tid) {
+ dev_err(&hci->master.dev,
+ "response tid=%d when expecting %d\n",
+ tid, xfer->cmd_tid);
+ /* let's pretend it is a prog error... any of them */
+ hci_pio_err(hci, pio, STAT_PROG_ERRORS);
+ return false;
+ }
+ xfer->response = resp;
+
+ if (pio->curr_rx == xfer) {
+ /*
+ * Response availability implies RX completion.
+ * Retrieve trailing RX data if any.
+ * Note that short reads are possible.
+ */
+ unsigned int received, expected, to_keep;
+
+ received = xfer->data_len - xfer->data_left;
+ expected = RESP_DATA_LENGTH(xfer->response);
+ if (expected > received) {
+ hci_pio_do_trailing_rx(hci, pio,
+ expected - received);
+ } else if (received > expected) {
+ /* we consumed data meant for next xfer */
+ to_keep = DIV_ROUND_UP(expected, 4);
+ hci_pio_push_to_next_rx(hci, xfer, to_keep);
+ }
+
+ /* then process the RX list pointer */
+ if (hci_pio_process_rx(hci, pio))
+ pio->enabled_irqs &= ~STAT_RX_THLD;
+ }
+
+ /*
+ * We're about to give back ownership of the xfer structure
+ * to the waiting instance. Make sure no reference to it
+ * still exists.
+ */
+ if (pio->curr_rx == xfer) {
+ DBG("short RX ?");
+ pio->curr_rx = pio->curr_rx->next_data;
+ } else if (pio->curr_tx == xfer) {
+ DBG("short TX ?");
+ pio->curr_tx = pio->curr_tx->next_data;
+ } else if (xfer->data_left) {
+ DBG("PIO xfer count = %d after response",
+ xfer->data_left);
+ }
+
+ pio->curr_resp = xfer->next_resp;
+ if (xfer->completion)
+ complete(xfer->completion);
+ }
+ return !pio->curr_resp;
+}
+
+static void hci_pio_queue_resp(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ struct hci_xfer *xfer = pio->curr_xfer;
+ struct hci_xfer *prev_queue_tail;
+
+ if (!(xfer->cmd_desc[0] & CMD_0_ROC))
+ return;
+
+ prev_queue_tail = pio->resp_queue;
+ pio->resp_queue = xfer;
+ if (pio->curr_resp) {
+ prev_queue_tail->next_resp = xfer;
+ } else {
+ pio->curr_resp = xfer;
+ if (!hci_pio_process_resp(hci, pio))
+ pio->enabled_irqs |= STAT_RESP_READY;
+ }
+}
+
+static bool hci_pio_process_cmd(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ while (pio->curr_xfer &&
+ (pio_reg_read(INTR_STATUS) & STAT_CMD_QUEUE_READY)) {
+ /*
+ * Always process the data FIFO before sending the command
+ * so needed TX data or RX space is available upfront.
+ */
+ hci_pio_queue_data(hci, pio);
+ /*
+ * Then queue our response request. This will also process
+ * the response FIFO in case it got suddenly filled up
+ * with results from previous commands.
+ */
+ hci_pio_queue_resp(hci, pio);
+ /*
+ * Finally send the command.
+ */
+ hci_pio_write_cmd(hci, pio->curr_xfer);
+ /*
+ * And move on.
+ */
+ pio->curr_xfer = pio->curr_xfer->next_xfer;
+ }
+ return !pio->curr_xfer;
+}
+
+static int hci_pio_queue_xfer(struct i3c_hci *hci, struct hci_xfer *xfer, int n)
+{
+ struct hci_pio_data *pio = hci->io_data;
+ struct hci_xfer *prev_queue_tail;
+ int i;
+
+ DBG("n = %d", n);
+
+ /* link xfer instances together and initialize data count */
+ for (i = 0; i < n; i++) {
+ xfer[i].next_xfer = (i + 1 < n) ? &xfer[i + 1] : NULL;
+ xfer[i].next_data = NULL;
+ xfer[i].next_resp = NULL;
+ xfer[i].data_left = xfer[i].data_len;
+ }
+
+ spin_lock_irq(&pio->lock);
+ prev_queue_tail = pio->xfer_queue;
+ pio->xfer_queue = &xfer[n - 1];
+ if (pio->curr_xfer) {
+ prev_queue_tail->next_xfer = xfer;
+ } else {
+ pio->curr_xfer = xfer;
+ if (!hci_pio_process_cmd(hci, pio))
+ pio->enabled_irqs |= STAT_CMD_QUEUE_READY;
+ pio_reg_write(INTR_SIGNAL_ENABLE, pio->enabled_irqs);
+ DBG("status = %#x/%#x",
+ pio_reg_read(INTR_STATUS), pio_reg_read(INTR_SIGNAL_ENABLE));
+ }
+ spin_unlock_irq(&pio->lock);
+ return 0;
+}
+
+static bool hci_pio_dequeue_xfer_common(struct i3c_hci *hci,
+ struct hci_pio_data *pio,
+ struct hci_xfer *xfer, int n)
+{
+ struct hci_xfer *p, **p_prev_next;
+ int i;
+
+ /*
+ * To safely dequeue a transfer request, it must be either entirely
+ * processed, or not yet processed at all. If our request tail is
+ * reachable from either the data or resp list that means the command
+ * was submitted and not yet completed.
+ */
+ for (p = pio->curr_resp; p; p = p->next_resp)
+ for (i = 0; i < n; i++)
+ if (p == &xfer[i])
+ goto pio_screwed;
+ for (p = pio->curr_rx; p; p = p->next_data)
+ for (i = 0; i < n; i++)
+ if (p == &xfer[i])
+ goto pio_screwed;
+ for (p = pio->curr_tx; p; p = p->next_data)
+ for (i = 0; i < n; i++)
+ if (p == &xfer[i])
+ goto pio_screwed;
+
+ /*
+ * The command was completed, or wasn't yet submitted.
+ * Unlink it from the que if the later.
+ */
+ p_prev_next = &pio->curr_xfer;
+ for (p = pio->curr_xfer; p; p = p->next_xfer) {
+ if (p == &xfer[0]) {
+ *p_prev_next = xfer[n - 1].next_xfer;
+ break;
+ }
+ p_prev_next = &p->next_xfer;
+ }
+
+ /* return true if we actually unqueued something */
+ return !!p;
+
+pio_screwed:
+ /*
+ * Life is tough. We must invalidate the hardware state and
+ * discard everything that is still queued.
+ */
+ for (p = pio->curr_resp; p; p = p->next_resp) {
+ p->response = FIELD_PREP(RESP_ERR_FIELD, RESP_ERR_HC_TERMINATED);
+ if (p->completion)
+ complete(p->completion);
+ }
+ for (p = pio->curr_xfer; p; p = p->next_xfer) {
+ p->response = FIELD_PREP(RESP_ERR_FIELD, RESP_ERR_HC_TERMINATED);
+ if (p->completion)
+ complete(p->completion);
+ }
+ pio->curr_xfer = pio->curr_rx = pio->curr_tx = pio->curr_resp = NULL;
+
+ return true;
+}
+
+static bool hci_pio_dequeue_xfer(struct i3c_hci *hci, struct hci_xfer *xfer, int n)
+{
+ struct hci_pio_data *pio = hci->io_data;
+ int ret;
+
+ spin_lock_irq(&pio->lock);
+ DBG("n=%d status=%#x/%#x", n,
+ pio_reg_read(INTR_STATUS), pio_reg_read(INTR_SIGNAL_ENABLE));
+ DBG("main_status = %#x/%#x",
+ readl(hci->base_regs + 0x20), readl(hci->base_regs + 0x28));
+
+ ret = hci_pio_dequeue_xfer_common(hci, pio, xfer, n);
+ spin_unlock_irq(&pio->lock);
+ return ret;
+}
+
+static void hci_pio_err(struct i3c_hci *hci, struct hci_pio_data *pio,
+ u32 status)
+{
+ /* TODO: this ought to be more sophisticated eventually */
+
+ if (pio_reg_read(INTR_STATUS) & STAT_RESP_READY) {
+ /* this may happen when an error is signaled with ROC unset */
+ u32 resp = pio_reg_read(RESPONSE_QUEUE_PORT);
+
+ dev_err(&hci->master.dev,
+ "orphan response (%#x) on error\n", resp);
+ }
+
+ /* dump states on programming errors */
+ if (status & STAT_PROG_ERRORS) {
+ u32 queue = pio_reg_read(QUEUE_CUR_STATUS);
+ u32 data = pio_reg_read(DATA_BUFFER_CUR_STATUS);
+
+ dev_err(&hci->master.dev,
+ "prog error %#lx (C/R/I = %ld/%ld/%ld, TX/RX = %ld/%ld)\n",
+ status & STAT_PROG_ERRORS,
+ FIELD_GET(CUR_CMD_Q_EMPTY_LEVEL, queue),
+ FIELD_GET(CUR_RESP_Q_LEVEL, queue),
+ FIELD_GET(CUR_IBI_Q_LEVEL, queue),
+ FIELD_GET(CUR_TX_BUF_LVL, data),
+ FIELD_GET(CUR_RX_BUF_LVL, data));
+ }
+
+ /* just bust out everything with pending responses for now */
+ hci_pio_dequeue_xfer_common(hci, pio, pio->curr_resp, 1);
+ /* ... and half-way TX transfers if any */
+ if (pio->curr_tx && pio->curr_tx->data_left != pio->curr_tx->data_len)
+ hci_pio_dequeue_xfer_common(hci, pio, pio->curr_tx, 1);
+ /* then reset the hardware */
+ mipi_i3c_hci_pio_reset(hci);
+ mipi_i3c_hci_resume(hci);
+
+ DBG("status=%#x/%#x",
+ pio_reg_read(INTR_STATUS), pio_reg_read(INTR_SIGNAL_ENABLE));
+}
+
+static void hci_pio_set_ibi_thresh(struct i3c_hci *hci,
+ struct hci_pio_data *pio,
+ unsigned int thresh_val)
+{
+ u32 regval = pio->reg_queue_thresh;
+
+ regval &= ~QUEUE_IBI_STATUS_THLD;
+ regval |= FIELD_PREP(QUEUE_IBI_STATUS_THLD, thresh_val);
+ /* write the threshold reg only if it changes */
+ if (regval != pio->reg_queue_thresh) {
+ pio_reg_write(QUEUE_THLD_CTRL, regval);
+ pio->reg_queue_thresh = regval;
+ DBG("%d", thresh_val);
+ }
+}
+
+static bool hci_pio_get_ibi_segment(struct i3c_hci *hci,
+ struct hci_pio_data *pio)
+{
+ struct hci_pio_ibi_data *ibi = &pio->ibi;
+ unsigned int nr_words, thresh_val;
+ u32 *p;
+
+ p = ibi->data_ptr;
+ p += (ibi->seg_len - ibi->seg_cnt) / 4;
+
+ while ((nr_words = ibi->seg_cnt/4)) {
+ /* determine our IBI queue threshold value */
+ thresh_val = min(nr_words, pio->max_ibi_thresh);
+ hci_pio_set_ibi_thresh(hci, pio, thresh_val);
+ /* bail out if we don't have that amount of data ready */
+ if (!(pio_reg_read(INTR_STATUS) & STAT_IBI_STATUS_THLD))
+ return false;
+ /* extract the data from the IBI port */
+ nr_words = thresh_val;
+ ibi->seg_cnt -= nr_words * 4;
+ DBG("now %d left %d", nr_words * 4, ibi->seg_cnt);
+ while (nr_words--)
+ *p++ = pio_reg_read(IBI_PORT);
+ }
+
+ if (ibi->seg_cnt) {
+ /*
+ * There are trailing bytes in the last word.
+ * Fetch it and extract bytes in an endian independent way.
+ * Unlike the TX case, we must not write past the end of
+ * the destination buffer.
+ */
+ u32 data;
+ u8 *p_byte = (u8 *)p;
+
+ hci_pio_set_ibi_thresh(hci, pio, 1);
+ if (!(pio_reg_read(INTR_STATUS) & STAT_IBI_STATUS_THLD))
+ return false;
+ DBG("trailing %d", ibi->seg_cnt);
+ data = pio_reg_read(IBI_PORT);
+ data = (__force u32) cpu_to_le32(data);
+ while (ibi->seg_cnt--) {
+ *p_byte++ = data;
+ data >>= 8;
+ }
+ }
+
+ return true;
+}
+
+static bool hci_pio_prep_new_ibi(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ struct hci_pio_ibi_data *ibi = &pio->ibi;
+ struct i3c_dev_desc *dev;
+ struct i3c_hci_dev_data *dev_data;
+ struct hci_pio_dev_ibi_data *dev_ibi;
+ u32 ibi_status;
+
+ /*
+ * We have a new IBI. Try to set up its payload retrieval.
+ * When returning true, the IBI data has to be consumed whether
+ * or not we are set up to capture it. If we return true with
+ * ibi->slot == NULL that means the data payload has to be
+ * drained out of the IBI port and dropped.
+ */
+
+ ibi_status = pio_reg_read(IBI_PORT);
+ DBG("status = %#x", ibi_status);
+ ibi->addr = FIELD_GET(IBI_TARGET_ADDR, ibi_status);
+ if (ibi_status & IBI_ERROR) {
+ dev_err(&hci->master.dev, "IBI error from %#x\n", ibi->addr);
+ return false;
+ }
+
+ ibi->last_seg = ibi_status & IBI_LAST_STATUS;
+ ibi->seg_len = FIELD_GET(IBI_DATA_LENGTH, ibi_status);
+ ibi->seg_cnt = ibi->seg_len;
+
+ dev = i3c_hci_addr_to_dev(hci, ibi->addr);
+ if (!dev) {
+ dev_err(&hci->master.dev,
+ "IBI for unknown device %#x\n", ibi->addr);
+ return true;
+ }
+
+ dev_data = i3c_dev_get_master_data(dev);
+ dev_ibi = dev_data->ibi_data;
+ ibi->max_len = dev_ibi->max_len;
+
+ if (ibi->seg_len > ibi->max_len) {
+ dev_err(&hci->master.dev, "IBI payload too big (%d > %d)\n",
+ ibi->seg_len, ibi->max_len);
+ return true;
+ }
+
+ ibi->slot = i3c_generic_ibi_get_free_slot(dev_ibi->pool);
+ if (!ibi->slot) {
+ dev_err(&hci->master.dev, "no free slot for IBI\n");
+ } else {
+ ibi->slot->len = 0;
+ ibi->data_ptr = ibi->slot->data;
+ }
+ return true;
+}
+
+static void hci_pio_free_ibi_slot(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ struct hci_pio_ibi_data *ibi = &pio->ibi;
+ struct hci_pio_dev_ibi_data *dev_ibi;
+
+ if (ibi->slot) {
+ dev_ibi = ibi->slot->dev->common.master_priv;
+ i3c_generic_ibi_recycle_slot(dev_ibi->pool, ibi->slot);
+ ibi->slot = NULL;
+ }
+}
+
+static bool hci_pio_process_ibi(struct i3c_hci *hci, struct hci_pio_data *pio)
+{
+ struct hci_pio_ibi_data *ibi = &pio->ibi;
+
+ if (!ibi->slot && !ibi->seg_cnt && ibi->last_seg)
+ if (!hci_pio_prep_new_ibi(hci, pio))
+ return false;
+
+ for (;;) {
+ u32 ibi_status;
+ unsigned int ibi_addr;
+
+ if (ibi->slot) {
+ if (!hci_pio_get_ibi_segment(hci, pio))
+ return false;
+ ibi->slot->len += ibi->seg_len;
+ ibi->data_ptr += ibi->seg_len;
+ if (ibi->last_seg) {
+ /* was the last segment: submit it and leave */
+ i3c_master_queue_ibi(ibi->slot->dev, ibi->slot);
+ ibi->slot = NULL;
+ hci_pio_set_ibi_thresh(hci, pio, 1);
+ return true;
+ }
+ } else if (ibi->seg_cnt) {
+ /*
+ * No slot but a non-zero count. This is the result
+ * of some error and the payload must be drained.
+ * This normally does not happen therefore no need
+ * to be extra optimized here.
+ */
+ hci_pio_set_ibi_thresh(hci, pio, 1);
+ do {
+ if (!(pio_reg_read(INTR_STATUS) & STAT_IBI_STATUS_THLD))
+ return false;
+ pio_reg_read(IBI_PORT);
+ } while (--ibi->seg_cnt);
+ if (ibi->last_seg)
+ return true;
+ }
+
+ /* try to move to the next segment right away */
+ hci_pio_set_ibi_thresh(hci, pio, 1);
+ if (!(pio_reg_read(INTR_STATUS) & STAT_IBI_STATUS_THLD))
+ return false;
+ ibi_status = pio_reg_read(IBI_PORT);
+ ibi_addr = FIELD_GET(IBI_TARGET_ADDR, ibi_status);
+ if (ibi->addr != ibi_addr) {
+ /* target address changed before last segment */
+ dev_err(&hci->master.dev,
+ "unexp IBI address changed from %d to %d\n",
+ ibi->addr, ibi_addr);
+ hci_pio_free_ibi_slot(hci, pio);
+ }
+ ibi->last_seg = ibi_status & IBI_LAST_STATUS;
+ ibi->seg_len = FIELD_GET(IBI_DATA_LENGTH, ibi_status);
+ ibi->seg_cnt = ibi->seg_len;
+ if (ibi->slot && ibi->slot->len + ibi->seg_len > ibi->max_len) {
+ dev_err(&hci->master.dev,
+ "IBI payload too big (%d > %d)\n",
+ ibi->slot->len + ibi->seg_len, ibi->max_len);
+ hci_pio_free_ibi_slot(hci, pio);
+ }
+ }
+
+ return false;
+}
+
+static int hci_pio_request_ibi(struct i3c_hci *hci, struct i3c_dev_desc *dev,
+ const struct i3c_ibi_setup *req)
+{
+ struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
+ struct i3c_generic_ibi_pool *pool;
+ struct hci_pio_dev_ibi_data *dev_ibi;
+
+ dev_ibi = kmalloc(sizeof(*dev_ibi), GFP_KERNEL);
+ if (!dev_ibi)
+ return -ENOMEM;
+ pool = i3c_generic_ibi_alloc_pool(dev, req);
+ if (IS_ERR(pool)) {
+ kfree(dev_ibi);
+ return PTR_ERR(pool);
+ }
+ dev_ibi->pool = pool;
+ dev_ibi->max_len = req->max_payload_len;
+ dev_data->ibi_data = dev_ibi;
+ return 0;
+}
+
+static void hci_pio_free_ibi(struct i3c_hci *hci, struct i3c_dev_desc *dev)
+{
+ struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
+ struct hci_pio_dev_ibi_data *dev_ibi = dev_data->ibi_data;
+
+ dev_data->ibi_data = NULL;
+ i3c_generic_ibi_free_pool(dev_ibi->pool);
+ kfree(dev_ibi);
+}
+
+static void hci_pio_recycle_ibi_slot(struct i3c_hci *hci,
+ struct i3c_dev_desc *dev,
+ struct i3c_ibi_slot *slot)
+{
+ struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
+ struct hci_pio_dev_ibi_data *dev_ibi = dev_data->ibi_data;
+
+ i3c_generic_ibi_recycle_slot(dev_ibi->pool, slot);
+}
+
+static bool hci_pio_irq_handler(struct i3c_hci *hci, unsigned int unused)
+{
+ struct hci_pio_data *pio = hci->io_data;
+ u32 status;
+
+ spin_lock(&pio->lock);
+ status = pio_reg_read(INTR_STATUS);
+ DBG("(in) status: %#x/%#x", status, pio->enabled_irqs);
+ status &= pio->enabled_irqs | STAT_LATENCY_WARNINGS;
+ if (!status) {
+ spin_unlock(&pio->lock);
+ return false;
+ }
+
+ if (status & STAT_IBI_STATUS_THLD)
+ hci_pio_process_ibi(hci, pio);
+
+ if (status & STAT_RX_THLD)
+ if (hci_pio_process_rx(hci, pio))
+ pio->enabled_irqs &= ~STAT_RX_THLD;
+ if (status & STAT_TX_THLD)
+ if (hci_pio_process_tx(hci, pio))
+ pio->enabled_irqs &= ~STAT_TX_THLD;
+ if (status & STAT_RESP_READY)
+ if (hci_pio_process_resp(hci, pio))
+ pio->enabled_irqs &= ~STAT_RESP_READY;
+
+ if (unlikely(status & STAT_LATENCY_WARNINGS)) {
+ pio_reg_write(INTR_STATUS, status & STAT_LATENCY_WARNINGS);
+ dev_warn_ratelimited(&hci->master.dev,
+ "encountered warning condition %#lx\n",
+ status & STAT_LATENCY_WARNINGS);
+ }
+
+ if (unlikely(status & STAT_ALL_ERRORS)) {
+ pio_reg_write(INTR_STATUS, status & STAT_ALL_ERRORS);
+ hci_pio_err(hci, pio, status & STAT_ALL_ERRORS);
+ }
+
+ if (status & STAT_CMD_QUEUE_READY)
+ if (hci_pio_process_cmd(hci, pio))
+ pio->enabled_irqs &= ~STAT_CMD_QUEUE_READY;
+
+ pio_reg_write(INTR_SIGNAL_ENABLE, pio->enabled_irqs);
+ DBG("(out) status: %#x/%#x",
+ pio_reg_read(INTR_STATUS), pio_reg_read(INTR_SIGNAL_ENABLE));
+ spin_unlock(&pio->lock);
+ return true;
+}
+
+const struct hci_io_ops mipi_i3c_hci_pio = {
+ .init = hci_pio_init,
+ .cleanup = hci_pio_cleanup,
+ .queue_xfer = hci_pio_queue_xfer,
+ .dequeue_xfer = hci_pio_dequeue_xfer,
+ .irq_handler = hci_pio_irq_handler,
+ .request_ibi = hci_pio_request_ibi,
+ .free_ibi = hci_pio_free_ibi,
+ .recycle_ibi_slot = hci_pio_recycle_ibi_slot,
+};