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linux-hardened/drivers/spi/spi_topcliff_pch.c
Grant Likely 65308c46b7 spi/topcliff: cleanups for style and conciseness 
This patch makes multiple cleanups to the new topcliff pch spi driver
including, but not limited to,
- removing superfluous brackets around variables
- open coding functions that are only used once
- removing unnecessary line breaks
- removing unused functions
- simplifying the interrupt enable/disable code
- remove unnecessary (void *) casts.
- remove b_mem_fail from pch_spi_set_tx to code it more cleanly
- shorten dev_dbg() messages for conciseness and readability

More cleanups are still needed in this driver.  In particular,
- the driver filename should be changed to spi_topcliff_pch.c
- many of the dev_dbg() lines should be trimmed (particularly the ones
  on unconditional code paths).
- I suspect that the locking model not correct.  I'd like to know what
  drivers' critical regions are, and how they are protected.
- get_resources and release_resources probably should be open coded in
  .probe and .release respectively.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00

1303 lines
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/*
* SPI bus driver for the Topcliff PCH used by Intel SoCs
*
* Copyright (C) 2010 OKI SEMICONDUCTOR Co., LTD.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/wait.h>
#include <linux/spi/spi.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/spi/spidev.h>
#include <linux/module.h>
#include <linux/device.h>
/* Register offsets */
#define PCH_SPCR 0x00 /* SPI control register */
#define PCH_SPBRR 0x04 /* SPI baud rate register */
#define PCH_SPSR 0x08 /* SPI status register */
#define PCH_SPDWR 0x0C /* SPI write data register */
#define PCH_SPDRR 0x10 /* SPI read data register */
#define PCH_SSNXCR 0x18 /* SSN Expand Control Register */
#define PCH_SRST 0x1C /* SPI reset register */
#define PCH_SPSR_TFD 0x000007C0
#define PCH_SPSR_RFD 0x0000F800
#define PCH_READABLE(x) (((x) & PCH_SPSR_RFD)>>11)
#define PCH_WRITABLE(x) (((x) & PCH_SPSR_TFD)>>6)
#define PCH_RX_THOLD 7
#define PCH_RX_THOLD_MAX 15
#define PCH_MAX_BAUDRATE 5000000
#define PCH_MAX_FIFO_DEPTH 16
#define STATUS_RUNNING 1
#define STATUS_EXITING 2
#define PCH_SLEEP_TIME 10
#define PCH_ADDRESS_SIZE 0x20
#define SSN_LOW 0x02U
#define SSN_NO_CONTROL 0x00U
#define PCH_MAX_CS 0xFF
#define PCI_DEVICE_ID_GE_SPI 0x8816
#define SPCR_SPE_BIT (1 << 0)
#define SPCR_MSTR_BIT (1 << 1)
#define SPCR_LSBF_BIT (1 << 4)
#define SPCR_CPHA_BIT (1 << 5)
#define SPCR_CPOL_BIT (1 << 6)
#define SPCR_TFIE_BIT (1 << 8)
#define SPCR_RFIE_BIT (1 << 9)
#define SPCR_FIE_BIT (1 << 10)
#define SPCR_ORIE_BIT (1 << 11)
#define SPCR_MDFIE_BIT (1 << 12)
#define SPCR_FICLR_BIT (1 << 24)
#define SPSR_TFI_BIT (1 << 0)
#define SPSR_RFI_BIT (1 << 1)
#define SPSR_FI_BIT (1 << 2)
#define SPBRR_SIZE_BIT (1 << 10)
#define PCH_ALL (SPCR_TFIE_BIT|SPCR_RFIE_BIT|SPCR_FIE_BIT|SPCR_ORIE_BIT|SPCR_MDFIE_BIT)
#define SPCR_RFIC_FIELD 20
#define SPCR_TFIC_FIELD 16
#define SPSR_INT_BITS 0x1F
#define MASK_SPBRR_SPBR_BITS (~((1 << 10) - 1))
#define MASK_RFIC_SPCR_BITS (~(0xf << 20))
#define MASK_TFIC_SPCR_BITS (~(0xf000f << 12))
#define PCH_CLOCK_HZ 50000000
#define PCH_MAX_SPBR 1023
/**
* struct pch_spi_data - Holds the SPI channel specific details
* @io_remap_addr: The remapped PCI base address
* @master: Pointer to the SPI master structure
* @work: Reference to work queue handler
* @wk: Workqueue for carrying out execution of the
* requests
* @wait: Wait queue for waking up upon receiving an
* interrupt.
* @transfer_complete: Status of SPI Transfer
* @bcurrent_msg_processing: Status flag for message processing
* @lock: Lock for protecting this structure
* @queue: SPI Message queue
* @status: Status of the SPI driver
* @bpw_len: Length of data to be transferred in bits per
* word
* @transfer_active: Flag showing active transfer
* @tx_index: Transmit data count; for bookkeeping during
* transfer
* @rx_index: Receive data count; for bookkeeping during
* transfer
* @tx_buff: Buffer for data to be transmitted
* @rx_index: Buffer for Received data
* @n_curnt_chip: The chip number that this SPI driver currently
* operates on
* @current_chip: Reference to the current chip that this SPI
* driver currently operates on
* @current_msg: The current message that this SPI driver is
* handling
* @cur_trans: The current transfer that this SPI driver is
* handling
* @board_dat: Reference to the SPI device data structure
*/
struct pch_spi_data {
void __iomem *io_remap_addr;
struct spi_master *master;
struct work_struct work;
struct workqueue_struct *wk;
wait_queue_head_t wait;
u8 transfer_complete;
u8 bcurrent_msg_processing;
spinlock_t lock;
struct list_head queue;
u8 status;
u32 bpw_len;
u8 transfer_active;
u32 tx_index;
u32 rx_index;
u16 *pkt_tx_buff;
u16 *pkt_rx_buff;
u8 n_curnt_chip;
struct spi_device *current_chip;
struct spi_message *current_msg;
struct spi_transfer *cur_trans;
struct pch_spi_board_data *board_dat;
};
/**
* struct pch_spi_board_data - Holds the SPI device specific details
* @pdev: Pointer to the PCI device
* @irq_reg_sts: Status of IRQ registration
* @pci_req_sts: Status of pci_request_regions
* @suspend_sts: Status of suspend
* @data: Pointer to SPI channel data structure
*/
struct pch_spi_board_data {
struct pci_dev *pdev;
u8 irq_reg_sts;
u8 pci_req_sts;
u8 suspend_sts;
struct pch_spi_data *data;
};
static struct pci_device_id pch_spi_pcidev_id[] = {
{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_GE_SPI)},
{0,}
};
/**
* pch_spi_writereg() - Performs register writes
* @master: Pointer to struct spi_master.
* @idx: Register offset.
* @val: Value to be written to register.
*/
static inline void pch_spi_writereg(struct spi_master *master, int idx, u32 val)
{
struct pch_spi_data *data = spi_master_get_devdata(master);
iowrite32(val, (data->io_remap_addr + idx));
}
/**
* pch_spi_readreg() - Performs register reads
* @master: Pointer to struct spi_master.
* @idx: Register offset.
*/
static inline u32 pch_spi_readreg(struct spi_master *master, int idx)
{
struct pch_spi_data *data = spi_master_get_devdata(master);
return ioread32(data->io_remap_addr + idx);
}
static inline void pch_spi_setclr_reg(struct spi_master *master, int idx,
u32 set, u32 clr)
{
u32 tmp = pch_spi_readreg(master, idx);
tmp = (tmp & ~clr) | set;
pch_spi_writereg(master, idx, tmp);
}
static void pch_spi_set_master_mode(struct spi_master *master)
{
pch_spi_setclr_reg(master, PCH_SPCR, SPCR_MSTR_BIT, 0);
}
/**
* pch_spi_clear_fifo() - Clears the Transmit and Receive FIFOs
* @master: Pointer to struct spi_master.
*/
static void pch_spi_clear_fifo(struct spi_master *master)
{
pch_spi_setclr_reg(master, PCH_SPCR, SPCR_FICLR_BIT, 0);
pch_spi_setclr_reg(master, PCH_SPCR, 0, SPCR_FICLR_BIT);
}
static void pch_spi_handler_sub(struct pch_spi_data *data, u32 reg_spsr_val,
void __iomem *io_remap_addr)
{
u32 n_read, tx_index, rx_index, bpw_len;
u16 *pkt_rx_buffer, *pkt_tx_buff;
int read_cnt;
u32 reg_spcr_val;
void __iomem *spsr;
void __iomem *spdrr;
void __iomem *spdwr;
spsr = io_remap_addr + PCH_SPSR;
iowrite32(reg_spsr_val, spsr);
if (data->transfer_active) {
rx_index = data->rx_index;
tx_index = data->tx_index;
bpw_len = data->bpw_len;
pkt_rx_buffer = data->pkt_rx_buff;
pkt_tx_buff = data->pkt_tx_buff;
spdrr = io_remap_addr + PCH_SPDRR;
spdwr = io_remap_addr + PCH_SPDWR;
n_read = PCH_READABLE(reg_spsr_val);
for (read_cnt = 0; (read_cnt < n_read); read_cnt++) {
pkt_rx_buffer[rx_index++] = ioread32(spdrr);
if (tx_index < bpw_len)
iowrite32(pkt_tx_buff[tx_index++], spdwr);
}
/* disable RFI if not needed */
if ((bpw_len - rx_index) <= PCH_MAX_FIFO_DEPTH) {
reg_spcr_val = ioread32(io_remap_addr + PCH_SPCR);
reg_spcr_val &= ~SPCR_RFIE_BIT; /* disable RFI */
/* reset rx threshold */
reg_spcr_val &= MASK_RFIC_SPCR_BITS;
reg_spcr_val |= (PCH_RX_THOLD_MAX << SPCR_RFIC_FIELD);
iowrite32(((reg_spcr_val) &= (~(SPCR_RFIE_BIT))),
(io_remap_addr + PCH_SPCR));
}
/* update counts */
data->tx_index = tx_index;
data->rx_index = rx_index;
}
/* if transfer complete interrupt */
if (reg_spsr_val & SPSR_FI_BIT) {
/* disable FI & RFI interrupts */
pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
SPCR_FIE_BIT | SPCR_TFIE_BIT);
/* transfer is completed;inform pch_spi_process_messages */
data->transfer_complete = true;
wake_up(&data->wait);
}
}
/**
* pch_spi_handler() - Interrupt handler
* @irq: The interrupt number.
* @dev_id: Pointer to struct pch_spi_board_data.
*/
static irqreturn_t pch_spi_handler(int irq, void *dev_id)
{
u32 reg_spsr_val;
struct pch_spi_data *data;
void __iomem *spsr;
void __iomem *io_remap_addr;
irqreturn_t ret = IRQ_NONE;
struct pch_spi_board_data *board_dat = dev_id;
if (board_dat->suspend_sts) {
dev_dbg(&board_dat->pdev->dev,
"%s returning due to suspend\n", __func__);
return IRQ_NONE;
}
data = board_dat->data;
io_remap_addr = data->io_remap_addr;
spsr = io_remap_addr + PCH_SPSR;
reg_spsr_val = ioread32(spsr);
/* Check if the interrupt is for SPI device */
if (reg_spsr_val & (SPSR_FI_BIT | SPSR_RFI_BIT)) {
pch_spi_handler_sub(data, reg_spsr_val, io_remap_addr);
ret = IRQ_HANDLED;
}
dev_dbg(&board_dat->pdev->dev, "%s EXIT return value=%d\n",
__func__, ret);
return ret;
}
/**
* pch_spi_set_baud_rate() - Sets SPBR field in SPBRR
* @master: Pointer to struct spi_master.
* @speed_hz: Baud rate.
*/
static void pch_spi_set_baud_rate(struct spi_master *master, u32 speed_hz)
{
u32 n_spbr = PCH_CLOCK_HZ / (speed_hz * 2);
/* if baud rate is less than we can support limit it */
if (n_spbr > PCH_MAX_SPBR)
n_spbr = PCH_MAX_SPBR;
pch_spi_setclr_reg(master, PCH_SPBRR, n_spbr, ~MASK_SPBRR_SPBR_BITS);
}
/**
* pch_spi_set_bits_per_word() - Sets SIZE field in SPBRR
* @master: Pointer to struct spi_master.
* @bits_per_word: Bits per word for SPI transfer.
*/
static void pch_spi_set_bits_per_word(struct spi_master *master,
u8 bits_per_word)
{
if (bits_per_word == 8)
pch_spi_setclr_reg(master, PCH_SPBRR, 0, SPBRR_SIZE_BIT);
else
pch_spi_setclr_reg(master, PCH_SPBRR, SPBRR_SIZE_BIT, 0);
}
/**
* pch_spi_setup_transfer() - Configures the PCH SPI hardware for transfer
* @spi: Pointer to struct spi_device.
*/
static void pch_spi_setup_transfer(struct spi_device *spi)
{
u32 flags = 0;
dev_dbg(&spi->dev, "%s SPBRR content =%x setting baud rate=%d\n",
__func__, pch_spi_readreg(spi->master, PCH_SPBRR),
spi->max_speed_hz);
pch_spi_set_baud_rate(spi->master, spi->max_speed_hz);
/* set bits per word */
pch_spi_set_bits_per_word(spi->master, spi->bits_per_word);
if (!(spi->mode & SPI_LSB_FIRST))
flags |= SPCR_LSBF_BIT;
if (spi->mode & SPI_CPOL)
flags |= SPCR_CPOL_BIT;
if (spi->mode & SPI_CPHA)
flags |= SPCR_CPHA_BIT;
pch_spi_setclr_reg(spi->master, PCH_SPCR, flags,
(SPCR_LSBF_BIT | SPCR_CPOL_BIT | SPCR_CPHA_BIT));
/* Clear the FIFO by toggling FICLR to 1 and back to 0 */
pch_spi_clear_fifo(spi->master);
}
/**
* pch_spi_reset() - Clears SPI registers
* @master: Pointer to struct spi_master.
*/
static void pch_spi_reset(struct spi_master *master)
{
/* write 1 to reset SPI */
pch_spi_writereg(master, PCH_SRST, 0x1);
/* clear reset */
pch_spi_writereg(master, PCH_SRST, 0x0);
}
static int pch_spi_setup(struct spi_device *pspi)
{
/* check bits per word */
if (pspi->bits_per_word == 0) {
pspi->bits_per_word = 8;
dev_dbg(&pspi->dev, "%s 8 bits per word\n", __func__);
}
if ((pspi->bits_per_word != 8) && (pspi->bits_per_word != 16)) {
dev_err(&pspi->dev, "%s Invalid bits per word\n", __func__);
return -EINVAL;
}
/* Check baud rate setting */
/* if baud rate of chip is greater than
max we can support,return error */
if ((pspi->max_speed_hz) > PCH_MAX_BAUDRATE)
pspi->max_speed_hz = PCH_MAX_BAUDRATE;
dev_dbg(&pspi->dev, "%s MODE = %x\n", __func__,
(pspi->mode) & (SPI_CPOL | SPI_CPHA));
return 0;
}
static int pch_spi_transfer(struct spi_device *pspi, struct spi_message *pmsg)
{
struct spi_transfer *transfer;
struct pch_spi_data *data = spi_master_get_devdata(pspi->master);
int retval;
unsigned long flags;
/* validate spi message and baud rate */
if (unlikely(list_empty(&pmsg->transfers) == 1)) {
dev_err(&pspi->dev, "%s list empty\n", __func__);
retval = -EINVAL;
goto err_out;
}
if (unlikely(pspi->max_speed_hz == 0)) {
dev_err(&pspi->dev, "%s pch_spi_tranfer maxspeed=%d\n",
__func__, pspi->max_speed_hz);
retval = -EINVAL;
goto err_out;
}
dev_dbg(&pspi->dev, "%s Transfer List not empty. "
"Transfer Speed is set.\n", __func__);
/* validate Tx/Rx buffers and Transfer length */
list_for_each_entry(transfer, &pmsg->transfers, transfer_list) {
if (!transfer->tx_buf && !transfer->rx_buf) {
dev_err(&pspi->dev,
"%s Tx and Rx buffer NULL\n", __func__);
retval = -EINVAL;
goto err_out;
}
if (!transfer->len) {
dev_err(&pspi->dev, "%s Transfer length invalid\n",
__func__);
retval = -EINVAL;
goto err_out;
}
dev_dbg(&pspi->dev, "%s Tx/Rx buffer valid. Transfer length"
" valid\n", __func__);
/* if baud rate hs been specified validate the same */
if (transfer->speed_hz > PCH_MAX_BAUDRATE)
transfer->speed_hz = PCH_MAX_BAUDRATE;
/* if bits per word has been specified validate the same */
if (transfer->bits_per_word) {
if ((transfer->bits_per_word != 8)
&& (transfer->bits_per_word != 16)) {
retval = -EINVAL;
dev_err(&pspi->dev,
"%s Invalid bits per word\n", __func__);
goto err_out;
}
}
}
spin_lock_irqsave(&data->lock, flags);
/* We won't process any messages if we have been asked to terminate */
if (data->status == STATUS_EXITING) {
dev_err(&pspi->dev, "%s status = STATUS_EXITING.\n", __func__);
retval = -ESHUTDOWN;
goto err_return_spinlock;
}
/* If suspended ,return -EINVAL */
if (data->board_dat->suspend_sts) {
dev_err(&pspi->dev, "%s suspend; returning EINVAL\n", __func__);
retval = -EINVAL;
goto err_return_spinlock;
}
/* set status of message */
pmsg->actual_length = 0;
dev_dbg(&pspi->dev, "%s - pmsg->status =%d\n", __func__, pmsg->status);
pmsg->status = -EINPROGRESS;
/* add message to queue */
list_add_tail(&pmsg->queue, &data->queue);
dev_dbg(&pspi->dev, "%s - Invoked list_add_tail\n", __func__);
/* schedule work queue to run */
queue_work(data->wk, &data->work);
dev_dbg(&pspi->dev, "%s - Invoked queue work\n", __func__);
retval = 0;
err_return_spinlock:
spin_unlock_irqrestore(&data->lock, flags);
err_out:
dev_dbg(&pspi->dev, "%s RETURN=%d\n", __func__, retval);
return retval;
}
static inline void pch_spi_select_chip(struct pch_spi_data *data,
struct spi_device *pspi)
{
if (data->current_chip != NULL) {
if (pspi->chip_select != data->n_curnt_chip) {
dev_dbg(&pspi->dev, "%s : different slave\n", __func__);
data->current_chip = NULL;
}
}
data->current_chip = pspi;
data->n_curnt_chip = data->current_chip->chip_select;
dev_dbg(&pspi->dev, "%s :Invoking pch_spi_setup_transfer\n", __func__);
pch_spi_setup_transfer(pspi);
}
static void pch_spi_set_tx(struct pch_spi_data *data, int *bpw,
struct spi_message **ppmsg)
{
int size;
u32 n_writes;
int j;
struct spi_message *pmsg;
const u8 *tx_buf;
const u16 *tx_sbuf;
pmsg = *ppmsg;
/* set baud rate if needed */
if (data->cur_trans->speed_hz) {
dev_dbg(&data->master->dev, "%s:setting baud rate\n", __func__);
pch_spi_set_baud_rate(data->master, data->cur_trans->speed_hz);
}
/* set bits per word if needed */
if (data->cur_trans->bits_per_word &&
(data->current_msg->spi->bits_per_word != data->cur_trans->bits_per_word)) {
dev_dbg(&data->master->dev, "%s:set bits per word\n", __func__);
pch_spi_set_bits_per_word(data->master,
data->cur_trans->bits_per_word);
*bpw = data->cur_trans->bits_per_word;
} else {
*bpw = data->current_msg->spi->bits_per_word;
}
/* reset Tx/Rx index */
data->tx_index = 0;
data->rx_index = 0;
data->bpw_len = data->cur_trans->len / (*bpw / 8);
/* find alloc size */
size = data->cur_trans->len * sizeof(*data->pkt_tx_buff);
/* allocate memory for pkt_tx_buff & pkt_rx_buffer */
data->pkt_tx_buff = kzalloc(size, GFP_KERNEL);
if (data->pkt_tx_buff != NULL) {
data->pkt_rx_buff = kzalloc(size, GFP_KERNEL);
if (!data->pkt_rx_buff)
kfree(data->pkt_tx_buff);
}
if (!data->pkt_rx_buff) {
/* flush queue and set status of all transfers to -ENOMEM */
dev_err(&data->master->dev, "%s :kzalloc failed\n", __func__);
list_for_each_entry(pmsg, data->queue.next, queue) {
pmsg->status = -ENOMEM;
if (pmsg->complete != 0)
pmsg->complete(pmsg->context);
/* delete from queue */
list_del_init(&pmsg->queue);
}
return;
}
/* copy Tx Data */
if (data->cur_trans->tx_buf != NULL) {
if (*bpw == 8) {
tx_buf = data->cur_trans->tx_buf;
for (j = 0; j < data->bpw_len; j++)
data->pkt_tx_buff[j] = *tx_buf++;
} else {
tx_sbuf = data->cur_trans->tx_buf;
for (j = 0; j < data->bpw_len; j++)
data->pkt_tx_buff[j] = *tx_sbuf++;
}
}
/* if len greater than PCH_MAX_FIFO_DEPTH, write 16,else len bytes */
n_writes = data->bpw_len;
if (n_writes > PCH_MAX_FIFO_DEPTH)
n_writes = PCH_MAX_FIFO_DEPTH;
dev_dbg(&data->master->dev, "\n%s:Pulling down SSN low - writing "
"0x2 to SSNXCR\n", __func__);
pch_spi_writereg(data->master, PCH_SSNXCR, SSN_LOW);
for (j = 0; j < n_writes; j++)
pch_spi_writereg(data->master, PCH_SPDWR, data->pkt_tx_buff[j]);
/* update tx_index */
data->tx_index = j;
/* reset transfer complete flag */
data->transfer_complete = false;
data->transfer_active = true;
}
static void pch_spi_nomore_transfer(struct pch_spi_data *data,
struct spi_message *pmsg)
{
dev_dbg(&data->master->dev, "%s called\n", __func__);
/* Invoke complete callback
* [To the spi core..indicating end of transfer] */
data->current_msg->status = 0;
if (data->current_msg->complete != 0) {
dev_dbg(&data->master->dev,
"%s:Invoking callback of SPI core\n", __func__);
data->current_msg->complete(data->current_msg->context);
}
/* update status in global variable */
data->bcurrent_msg_processing = false;
dev_dbg(&data->master->dev,
"%s:data->bcurrent_msg_processing = false\n", __func__);
data->current_msg = NULL;
data->cur_trans = NULL;
/* check if we have items in list and not suspending
* return 1 if list empty */
if ((list_empty(&data->queue) == 0) &&
(!data->board_dat->suspend_sts) &&
(data->status != STATUS_EXITING)) {
/* We have some more work to do (either there is more tranint
* bpw;sfer requests in the current message or there are
*more messages)
*/
dev_dbg(&data->master->dev, "%s:Invoke queue_work\n", __func__);
queue_work(data->wk, &data->work);
} else if (data->board_dat->suspend_sts ||
data->status == STATUS_EXITING) {
dev_dbg(&data->master->dev,
"%s suspend/remove initiated, flushing queue\n",
__func__);
list_for_each_entry(pmsg, data->queue.next, queue) {
pmsg->status = -EIO;
if (pmsg->complete)
pmsg->complete(pmsg->context);
/* delete from queue */
list_del_init(&pmsg->queue);
}
}
}
static void pch_spi_set_ir(struct pch_spi_data *data)
{
/* enable interrupts */
if ((data->bpw_len) > PCH_MAX_FIFO_DEPTH) {
/* set receive threhold to PCH_RX_THOLD */
pch_spi_setclr_reg(data->master, PCH_SPCR,
PCH_RX_THOLD << SPCR_TFIC_FIELD,
~MASK_TFIC_SPCR_BITS);
/* enable FI and RFI interrupts */
pch_spi_setclr_reg(data->master, PCH_SPCR,
SPCR_RFIE_BIT | SPCR_TFIE_BIT, 0);
} else {
/* set receive threhold to maximum */
pch_spi_setclr_reg(data->master, PCH_SPCR,
PCH_RX_THOLD_MAX << SPCR_TFIC_FIELD,
~MASK_TFIC_SPCR_BITS);
/* enable FI interrupt */
pch_spi_setclr_reg(data->master, PCH_SPCR, SPCR_FIE_BIT, 0);
}
dev_dbg(&data->master->dev,
"%s:invoking pch_spi_set_enable to enable SPI\n", __func__);
/* SPI set enable */
pch_spi_setclr_reg(data->current_chip->master, PCH_SPCR, SPCR_SPE_BIT, 0);
/* Wait until the transfer completes; go to sleep after
initiating the transfer. */
dev_dbg(&data->master->dev,
"%s:waiting for transfer to get over\n", __func__);
wait_event_interruptible(data->wait, data->transfer_complete);
pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
dev_dbg(&data->master->dev,
"%s:no more control over SSN-writing 0 to SSNXCR.", __func__);
data->transfer_active = false;
dev_dbg(&data->master->dev,
"%s set data->transfer_active = false\n", __func__);
/* clear all interrupts */
pch_spi_writereg(data->master, PCH_SPSR,
pch_spi_readreg(data->master, PCH_SPSR));
/* disable interrupts */
pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
}
static void pch_spi_copy_rx_data(struct pch_spi_data *data, int bpw)
{
int j;
u8 *rx_buf;
u16 *rx_sbuf;
/* copy Rx Data */
if (!data->cur_trans->rx_buf)
return;
if (bpw == 8) {
rx_buf = data->cur_trans->rx_buf;
for (j = 0; j < data->bpw_len; j++)
*rx_buf++ = data->pkt_rx_buff[j] & 0xFF;
} else {
rx_sbuf = data->cur_trans->rx_buf;
for (j = 0; j < data->bpw_len; j++)
*rx_sbuf++ = data->pkt_rx_buff[j];
}
}
static void pch_spi_process_messages(struct work_struct *pwork)
{
struct spi_message *pmsg;
struct pch_spi_data *data;
int bpw;
dev_dbg(&data->master->dev, "%s data initialized\n", __func__);
data = container_of(pwork, struct pch_spi_data, work);
spin_lock(&data->lock);
/* check if suspend has been initiated;if yes flush queue */
if (data->board_dat->suspend_sts || (data->status == STATUS_EXITING)) {
dev_dbg(&data->master->dev,
"%s suspend/remove initiated,flushing queue\n",
__func__);
list_for_each_entry(pmsg, data->queue.next, queue) {
pmsg->status = -EIO;
if (pmsg->complete != 0) {
spin_unlock(&data->lock);
pmsg->complete(pmsg->context);
spin_lock(&data->lock);
}
/* delete from queue */
list_del_init(&pmsg->queue);
}
spin_unlock(&data->lock);
return;
}
data->bcurrent_msg_processing = true;
dev_dbg(&data->master->dev,
"%s Set data->bcurrent_msg_processing= true\n", __func__);
/* Get the message from the queue and delete it from there. */
data->current_msg = list_entry(data->queue.next, struct spi_message,
queue);
list_del_init(&data->current_msg->queue);
data->current_msg->status = 0;
pch_spi_select_chip(data, data->current_msg->spi);
spin_unlock(&data->lock);
do {
/* If we are already processing a message get the next
transfer structure from the message otherwise retrieve
the 1st transfer request from the message. */
spin_lock(&data->lock);
if (data->cur_trans == NULL) {
data->cur_trans =
list_entry(data->current_msg->transfers.
next, struct spi_transfer,
transfer_list);
dev_dbg(&data->master->dev,
"%s :Getting 1st transfer message\n", __func__);
} else {
data->cur_trans =
list_entry(data->cur_trans->transfer_list.next,
struct spi_transfer,
transfer_list);
dev_dbg(&data->master->dev,
"%s :Getting next transfer message\n",
__func__);
}
spin_unlock(&data->lock);
pch_spi_set_tx(data, &bpw, &pmsg);
/* Control interrupt*/
pch_spi_set_ir(data);
/* Disable SPI transfer */
pch_spi_setclr_reg(data->current_chip->master, PCH_SPCR, 0,
SPCR_SPE_BIT);
/* clear FIFO */
pch_spi_clear_fifo(data->master);
/* copy Rx Data */
pch_spi_copy_rx_data(data, bpw);
/* free memory */
kfree(data->pkt_rx_buff);
data->pkt_rx_buff = NULL;
kfree(data->pkt_tx_buff);
data->pkt_tx_buff = NULL;
/* increment message count */
data->current_msg->actual_length += data->cur_trans->len;
dev_dbg(&data->master->dev,
"%s:data->current_msg->actual_length=%d\n",
__func__, data->current_msg->actual_length);
/* check for delay */
if (data->cur_trans->delay_usecs) {
dev_dbg(&data->master->dev, "%s:"
"delay in usec=%d\n", __func__,
data->cur_trans->delay_usecs);
udelay(data->cur_trans->delay_usecs);
}
spin_lock(&data->lock);
/* No more transfer in this message. */
if ((data->cur_trans->transfer_list.next) ==
&(data->current_msg->transfers)) {
pch_spi_nomore_transfer(data, pmsg);
}
spin_unlock(&data->lock);
} while (data->cur_trans != NULL);
}
static void pch_spi_free_resources(struct pch_spi_board_data *board_dat)
{
dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
/* free workqueue */
if (board_dat->data->wk != NULL) {
destroy_workqueue(board_dat->data->wk);
board_dat->data->wk = NULL;
dev_dbg(&board_dat->pdev->dev,
"%s destroy_workqueue invoked successfully\n",
__func__);
}
/* disable interrupts & free IRQ */
if (board_dat->irq_reg_sts) {
/* disable interrupts */
pch_spi_setclr_reg(board_dat->data->master, PCH_SPCR, 0,
PCH_ALL);
/* free IRQ */
free_irq(board_dat->pdev->irq, board_dat);
dev_dbg(&board_dat->pdev->dev,
"%s free_irq invoked successfully\n", __func__);
board_dat->irq_reg_sts = false;
}
/* unmap PCI base address */
if (board_dat->data->io_remap_addr != 0) {
pci_iounmap(board_dat->pdev, board_dat->data->io_remap_addr);
board_dat->data->io_remap_addr = 0;
dev_dbg(&board_dat->pdev->dev,
"%s pci_iounmap invoked successfully\n", __func__);
}
/* release PCI region */
if (board_dat->pci_req_sts) {
pci_release_regions(board_dat->pdev);
dev_dbg(&board_dat->pdev->dev,
"%s pci_release_regions invoked successfully\n",
__func__);
board_dat->pci_req_sts = false;
}
}
static int pch_spi_get_resources(struct pch_spi_board_data *board_dat)
{
void __iomem *io_remap_addr;
int retval;
dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__);
/* create workqueue */
board_dat->data->wk = create_singlethread_workqueue(KBUILD_MODNAME);
if (!board_dat->data->wk) {
dev_err(&board_dat->pdev->dev,
"%s create_singlet hread_workqueue failed\n", __func__);
retval = -EBUSY;
goto err_return;
}
dev_dbg(&board_dat->pdev->dev,
"%s create_singlethread_workqueue success\n", __func__);
retval = pci_request_regions(board_dat->pdev, KBUILD_MODNAME);
if (retval != 0) {
dev_err(&board_dat->pdev->dev,
"%s request_region failed\n", __func__);
goto err_return;
}
board_dat->pci_req_sts = true;
io_remap_addr = pci_iomap(board_dat->pdev, 1, 0);
if (io_remap_addr == 0) {
dev_err(&board_dat->pdev->dev,
"%s pci_iomap failed\n", __func__);
retval = -ENOMEM;
goto err_return;
}
/* calculate base address for all channels */
board_dat->data->io_remap_addr = io_remap_addr;
/* reset PCH SPI h/w */
pch_spi_reset(board_dat->data->master);
dev_dbg(&board_dat->pdev->dev,
"%s pch_spi_reset invoked successfully\n", __func__);
/* register IRQ */
retval = request_irq(board_dat->pdev->irq, pch_spi_handler,
IRQF_SHARED, KBUILD_MODNAME, board_dat);
if (retval != 0) {
dev_err(&board_dat->pdev->dev,
"%s request_irq failed\n", __func__);
goto err_return;
}
dev_dbg(&board_dat->pdev->dev, "%s request_irq returned=%d\n",
__func__, retval);
board_dat->irq_reg_sts = true;
dev_dbg(&board_dat->pdev->dev, "%s data->irq_reg_sts=true\n", __func__);
err_return:
if (retval != 0) {
dev_err(&board_dat->pdev->dev,
"%s FAIL:invoking pch_spi_free_resources\n", __func__);
pch_spi_free_resources(board_dat);
}
dev_dbg(&board_dat->pdev->dev, "%s Return=%d\n", __func__, retval);
return retval;
}
static int pch_spi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct spi_master *master;
struct pch_spi_board_data *board_dat;
int retval;
dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
/* allocate memory for private data */
board_dat = kzalloc(sizeof(struct pch_spi_board_data), GFP_KERNEL);
if (board_dat == NULL) {
dev_err(&pdev->dev,
" %s memory allocation for private data failed\n",
__func__);
retval = -ENOMEM;
goto err_kmalloc;
}
dev_dbg(&pdev->dev,
"%s memory allocation for private data success\n", __func__);
/* enable PCI device */
retval = pci_enable_device(pdev);
if (retval != 0) {
dev_err(&pdev->dev, "%s pci_enable_device FAILED\n", __func__);
goto err_pci_en_device;
}
dev_dbg(&pdev->dev, "%s pci_enable_device returned=%d\n",
__func__, retval);
board_dat->pdev = pdev;
/* alllocate memory for SPI master */
master = spi_alloc_master(&pdev->dev, sizeof(struct pch_spi_data));
if (master == NULL) {
retval = -ENOMEM;
dev_err(&pdev->dev, "%s Fail.\n", __func__);
goto err_spi_alloc_master;
}
dev_dbg(&pdev->dev,
"%s spi_alloc_master returned non NULL\n", __func__);
/* initialize members of SPI master */
master->bus_num = -1;
master->num_chipselect = PCH_MAX_CS;
master->setup = pch_spi_setup;
master->transfer = pch_spi_transfer;
dev_dbg(&pdev->dev,
"%s transfer member of SPI master initialized\n", __func__);
board_dat->data = spi_master_get_devdata(master);
board_dat->data->master = master;
board_dat->data->n_curnt_chip = 255;
board_dat->data->board_dat = board_dat;
board_dat->data->status = STATUS_RUNNING;
INIT_LIST_HEAD(&board_dat->data->queue);
spin_lock_init(&board_dat->data->lock);
INIT_WORK(&board_dat->data->work, pch_spi_process_messages);
init_waitqueue_head(&board_dat->data->wait);
/* allocate resources for PCH SPI */
retval = pch_spi_get_resources(board_dat);
if (retval) {
dev_err(&pdev->dev, "%s fail(retval=%d)\n", __func__, retval);
goto err_spi_get_resources;
}
dev_dbg(&pdev->dev, "%s pch_spi_get_resources returned=%d\n",
__func__, retval);
/* save private data in dev */
pci_set_drvdata(pdev, board_dat);
dev_dbg(&pdev->dev, "%s invoked pci_set_drvdata\n", __func__);
/* set master mode */
pch_spi_set_master_mode(master);
dev_dbg(&pdev->dev,
"%s invoked pch_spi_set_master_mode\n", __func__);
/* Register the controller with the SPI core. */
retval = spi_register_master(master);
if (retval != 0) {
dev_err(&pdev->dev,
"%s spi_register_master FAILED\n", __func__);
goto err_spi_reg_master;
}
dev_dbg(&pdev->dev, "%s spi_register_master returned=%d\n",
__func__, retval);
return 0;
err_spi_reg_master:
spi_unregister_master(master);
err_spi_get_resources:
err_spi_alloc_master:
spi_master_put(master);
pci_disable_device(pdev);
err_pci_en_device:
kfree(board_dat);
err_kmalloc:
return retval;
}
static void pch_spi_remove(struct pci_dev *pdev)
{
struct pch_spi_board_data *board_dat = pci_get_drvdata(pdev);
int count;
dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
if (!board_dat) {
dev_err(&pdev->dev,
"%s pci_get_drvdata returned NULL\n", __func__);
return;
}
/* check for any pending messages; no action is taken if the queue
* is still full; but at least we tried. Unload anyway */
count = 500;
spin_lock(&board_dat->data->lock);
board_dat->data->status = STATUS_EXITING;
while ((list_empty(&board_dat->data->queue) == 0) && --count) {
dev_dbg(&board_dat->pdev->dev, "%s :queue not empty\n",
__func__);
spin_unlock(&board_dat->data->lock);
msleep(PCH_SLEEP_TIME);
spin_lock(&board_dat->data->lock);
}
spin_unlock(&board_dat->data->lock);
/* Free resources allocated for PCH SPI */
pch_spi_free_resources(board_dat);
spi_unregister_master(board_dat->data->master);
/* free memory for private data */
kfree(board_dat);
pci_set_drvdata(pdev, NULL);
/* disable PCI device */
pci_disable_device(pdev);
dev_dbg(&pdev->dev, "%s invoked pci_disable_device\n", __func__);
}
#ifdef CONFIG_PM
static int pch_spi_suspend(struct pci_dev *pdev, pm_message_t state)
{
u8 count;
int retval;
struct pch_spi_board_data *board_dat = pci_get_drvdata(pdev);
dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
if (!board_dat) {
dev_err(&pdev->dev,
"%s pci_get_drvdata returned NULL\n", __func__);
return -EFAULT;
}
retval = 0;
board_dat->suspend_sts = true;
/* check if the current message is processed:
Only after thats done the transfer will be suspended */
count = 255;
while ((--count) > 0) {
if (!(board_dat->data->bcurrent_msg_processing)) {
dev_dbg(&pdev->dev, "%s board_dat->data->bCurrent_"
"msg_processing = false\n", __func__);
break;
} else {
dev_dbg(&pdev->dev, "%s board_dat->data->bCurrent_msg_"
"processing = true\n", __func__);
}
msleep(PCH_SLEEP_TIME);
}
/* Free IRQ */
if (board_dat->irq_reg_sts) {
/* disable all interrupts */
pch_spi_setclr_reg(board_dat->data->master, PCH_SPCR, 0,
PCH_ALL);
pch_spi_reset(board_dat->data->master);
free_irq(board_dat->pdev->irq, board_dat);
board_dat->irq_reg_sts = false;
dev_dbg(&pdev->dev,
"%s free_irq invoked successfully.\n", __func__);
}
/* save config space */
retval = pci_save_state(pdev);
if (retval == 0) {
dev_dbg(&pdev->dev, "%s pci_save_state returned=%d\n",
__func__, retval);
/* disable PM notifications */
pci_enable_wake(pdev, PCI_D3hot, 0);
dev_dbg(&pdev->dev,
"%s pci_enable_wake invoked successfully\n", __func__);
/* disable PCI device */
pci_disable_device(pdev);
dev_dbg(&pdev->dev,
"%s pci_disable_device invoked successfully\n",
__func__);
/* move device to D3hot state */
pci_set_power_state(pdev, PCI_D3hot);
dev_dbg(&pdev->dev,
"%s pci_set_power_state invoked successfully\n",
__func__);
} else {
dev_err(&pdev->dev, "%s pci_save_state failed\n", __func__);
}
dev_dbg(&pdev->dev, "%s return=%d\n", __func__, retval);
return retval;
}
static int pch_spi_resume(struct pci_dev *pdev)
{
int retval;
struct pch_spi_board_data *board = pci_get_drvdata(pdev);
dev_dbg(&pdev->dev, "%s ENTRY\n", __func__);
if (!board) {
dev_err(&pdev->dev,
"%s pci_get_drvdata returned NULL\n", __func__);
return -EFAULT;
}
/* move device to DO power state */
pci_set_power_state(pdev, PCI_D0);
/* restore state */
pci_restore_state(pdev);
retval = pci_enable_device(pdev);
if (retval < 0) {
dev_err(&pdev->dev,
"%s pci_enable_device failed\n", __func__);
} else {
/* disable PM notifications */
pci_enable_wake(pdev, PCI_D3hot, 0);
/* register IRQ handler */
if (!board->irq_reg_sts) {
/* register IRQ */
retval = request_irq(board->pdev->irq, pch_spi_handler,
IRQF_SHARED, KBUILD_MODNAME,
board);
if (retval < 0) {
dev_err(&pdev->dev,
"%s request_irq failed\n", __func__);
return retval;
}
board->irq_reg_sts = true;
/* reset PCH SPI h/w */
pch_spi_reset(board->data->master);
pch_spi_set_master_mode(board->data->master);
/* set suspend status to false */
board->suspend_sts = false;
}
}
dev_dbg(&pdev->dev, "%s returning=%d\n", __func__, retval);
return retval;
}
#else
#define pch_spi_suspend NULL
#define pch_spi_resume NULL
#endif
static struct pci_driver pch_spi_pcidev = {
.name = "pch_spi",
.id_table = pch_spi_pcidev_id,
.probe = pch_spi_probe,
.remove = pch_spi_remove,
.suspend = pch_spi_suspend,
.resume = pch_spi_resume,
};
static int __init pch_spi_init(void)
{
return pci_register_driver(&pch_spi_pcidev);
}
module_init(pch_spi_init);
static void __exit pch_spi_exit(void)
{
pci_unregister_driver(&pch_spi_pcidev);
}
module_exit(pch_spi_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Topcliff PCH SPI PCI Driver");
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