diff options
Diffstat (limited to 'drivers/i3c/master/mipi-i3c-hci/pio.c')
| -rw-r--r-- | drivers/i3c/master/mipi-i3c-hci/pio.c | 1041 |
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 0000000000..d0272aa935 --- /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, +}; |