/*
* Driver for Amlogic Meson SPI communication controller (SPICC)
*
* Copyright (C) BayLibre, SAS
* Author: Neil Armstrong <[email protected]>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/reset.h>
#include <linux/pinctrl/consumer.h>
/*
* The Meson SPICC controller could support DMA based transfers, but is not
* implemented by the vendor code, and while having the registers documentation
* it has never worked on the GXL Hardware.
* The PIO mode is the only mode implemented, and due to badly designed HW :
* - all transfers are cutted in 16 words burst because the FIFO hangs on
* TX underflow, and there is no TX "Half-Empty" interrupt, so we go by
* FIFO max size chunk only
* - CS management is dumb, and goes UP between every burst, so is really a
* "Data Valid" signal than a Chip Select, GPIO link should be used instead
* to have a CS go down over the full transfer
*/
#define SPICC_MAX_BURST 128
/* Register Map */
#define SPICC_RXDATA 0x00
#define SPICC_TXDATA 0x04
#define SPICC_CONREG 0x08
#define SPICC_ENABLE BIT(0)
#define SPICC_MODE_MASTER BIT(1)
#define SPICC_XCH BIT(2)
#define SPICC_SMC BIT(3)
#define SPICC_POL BIT(4)
#define SPICC_PHA BIT(5)
#define SPICC_SSCTL BIT(6)
#define SPICC_SSPOL BIT(7)
#define SPICC_DRCTL_MASK GENMASK(9, 8)
#define SPICC_DRCTL_IGNORE 0
#define SPICC_DRCTL_FALLING 1
#define SPICC_DRCTL_LOWLEVEL 2
#define SPICC_CS_MASK GENMASK(13, 12)
#define SPICC_DATARATE_MASK GENMASK(18, 16)
#define SPICC_DATARATE_DIV4 0
#define SPICC_DATARATE_DIV8 1
#define SPICC_DATARATE_DIV16 2
#define SPICC_DATARATE_DIV32 3
#define SPICC_BITLENGTH_MASK GENMASK(24, 19)
#define SPICC_BURSTLENGTH_MASK GENMASK(31, 25)
#define SPICC_INTREG 0x0c
#define SPICC_TE_EN BIT(0) /* TX FIFO Empty Interrupt */
#define SPICC_TH_EN BIT(1) /* TX FIFO Half-Full Interrupt */
#define SPICC_TF_EN BIT(2) /* TX FIFO Full Interrupt */
#define SPICC_RR_EN BIT(3) /* RX FIFO Ready Interrupt */
#define SPICC_RH_EN BIT(4) /* RX FIFO Half-Full Interrupt */
#define SPICC_RF_EN BIT(5) /* RX FIFO Full Interrupt */
#define SPICC_RO_EN BIT(6) /* RX FIFO Overflow Interrupt */
#define SPICC_TC_EN BIT(7) /* Transfert Complete Interrupt */
#define SPICC_DMAREG 0x10
#define SPICC_DMA_ENABLE BIT(0)
#define SPICC_TXFIFO_THRESHOLD_MASK GENMASK(5, 1)
#define SPICC_RXFIFO_THRESHOLD_MASK GENMASK(10, 6)
#define SPICC_READ_BURST_MASK GENMASK(14, 11)
#define SPICC_WRITE_BURST_MASK GENMASK(18, 15)
#define SPICC_DMA_URGENT BIT(19)
#define SPICC_DMA_THREADID_MASK GENMASK(25, 20)
#define SPICC_DMA_BURSTNUM_MASK GENMASK(31, 26)
#define SPICC_STATREG 0x14
#define SPICC_TE BIT(0) /* TX FIFO Empty Interrupt */
#define SPICC_TH BIT(1) /* TX FIFO Half-Full Interrupt */
#define SPICC_TF BIT(2) /* TX FIFO Full Interrupt */
#define SPICC_RR BIT(3) /* RX FIFO Ready Interrupt */
#define SPICC_RH BIT(4) /* RX FIFO Half-Full Interrupt */
#define SPICC_RF BIT(5) /* RX FIFO Full Interrupt */
#define SPICC_RO BIT(6) /* RX FIFO Overflow Interrupt */
#define SPICC_TC BIT(7) /* Transfert Complete Interrupt */
#define SPICC_PERIODREG 0x18
#define SPICC_PERIOD GENMASK(14, 0) /* Wait cycles */
#define SPICC_TESTREG 0x1c
#define SPICC_TXCNT_MASK GENMASK(4, 0) /* TX FIFO Counter */
#define SPICC_RXCNT_MASK GENMASK(9, 5) /* RX FIFO Counter */
#define SPICC_SMSTATUS_MASK GENMASK(12, 10) /* State Machine Status */
#define SPICC_LBC_RO BIT(13) /* Loop Back Control Read-Only */
#define SPICC_LBC_W1 BIT(14) /* Loop Back Control Write-Only */
#define SPICC_SWAP_RO BIT(14) /* RX FIFO Data Swap Read-Only */
#define SPICC_SWAP_W1 BIT(15) /* RX FIFO Data Swap Write-Only */
#define SPICC_DLYCTL_RO_MASK GENMASK(20, 15) /* Delay Control Read-Only */
#define SPICC_MO_DELAY_MASK GENMASK(17, 16) /* Master Output Delay */
#define SPICC_MO_NO_DELAY 0
#define SPICC_MO_DELAY_1_CYCLE 1
#define SPICC_MO_DELAY_2_CYCLE 2
#define SPICC_MO_DELAY_3_CYCLE 3
#define SPICC_MI_DELAY_MASK GENMASK(19, 18) /* Master Input Delay */
#define SPICC_MI_NO_DELAY 0
#define SPICC_MI_DELAY_1_CYCLE 1
#define SPICC_MI_DELAY_2_CYCLE 2
#define SPICC_MI_DELAY_3_CYCLE 3
#define SPICC_MI_CAP_DELAY_MASK GENMASK(21, 20) /* Master Capture Delay */
#define SPICC_CAP_AHEAD_2_CYCLE 0
#define SPICC_CAP_AHEAD_1_CYCLE 1
#define SPICC_CAP_NO_DELAY 2
#define SPICC_CAP_DELAY_1_CYCLE 3
#define SPICC_FIFORST_RO_MASK GENMASK(22, 21) /* FIFO Softreset Read-Only */
#define SPICC_FIFORST_W1_MASK GENMASK(23, 22) /* FIFO Softreset Write-Only */
#define SPICC_DRADDR 0x20 /* Read Address of DMA */
#define SPICC_DWADDR 0x24 /* Write Address of DMA */
#define SPICC_ENH_CTL0 0x38 /* Enhanced Feature */
#define SPICC_ENH_CLK_CS_DELAY_MASK GENMASK(15, 0)
#define SPICC_ENH_DATARATE_MASK GENMASK(23, 16)
#define SPICC_ENH_DATARATE_EN BIT(24)
#define SPICC_ENH_MOSI_OEN BIT(25)
#define SPICC_ENH_CLK_OEN BIT(26)
#define SPICC_ENH_CS_OEN BIT(27)
#define SPICC_ENH_CLK_CS_DELAY_EN BIT(28)
#define SPICC_ENH_MAIN_CLK_AO BIT(29)
#define writel_bits_relaxed(mask, val, addr) \
writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr)
struct meson_spicc_data {
unsigned int max_speed_hz;
unsigned int min_speed_hz;
unsigned int fifo_size;
bool has_oen;
bool has_enhance_clk_div;
bool has_pclk;
};
struct meson_spicc_device {
struct spi_controller *host;
struct platform_device *pdev;
void __iomem *base;
struct clk *core;
struct clk *pclk;
struct clk_divider pow2_div;
struct clk *clk;
struct spi_message *message;
struct spi_transfer *xfer;
struct completion done;
const struct meson_spicc_data *data;
u8 *tx_buf;
u8 *rx_buf;
unsigned int bytes_per_word;
unsigned long tx_remain;
unsigned long rx_remain;
unsigned long xfer_remain;
struct pinctrl *pinctrl;
struct pinctrl_state *pins_idle_high;
struct pinctrl_state *pins_idle_low;
};
#define pow2_clk_to_spicc(_div) container_of(_div, struct meson_spicc_device, pow2_div)
static void meson_spicc_oen_enable(struct meson_spicc_device *spicc)
{
u32 conf;
if (!spicc->data->has_oen) {
/* Try to get pinctrl states for idle high/low */
spicc->pins_idle_high = pinctrl_lookup_state(spicc->pinctrl,
"idle-high");
if (IS_ERR(spicc->pins_idle_high)) {
dev_warn(&spicc->pdev->dev, "can't get idle-high pinctrl\n");
spicc->pins_idle_high = NULL;
}
spicc->pins_idle_low = pinctrl_lookup_state(spicc->pinctrl,
"idle-low");
if (IS_ERR(spicc->pins_idle_low)) {
dev_warn(&spicc->pdev->dev, "can't get idle-low pinctrl\n");
spicc->pins_idle_low = NULL;
}
return;
}
conf = readl_relaxed(spicc->base + SPICC_ENH_CTL0) |
SPICC_ENH_MOSI_OEN | SPICC_ENH_CLK_OEN | SPICC_ENH_CS_OEN;
writel_relaxed(conf, spicc->base + SPICC_ENH_CTL0);
}
static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc)
{
return !!FIELD_GET(SPICC_TF,
readl_relaxed(spicc->base + SPICC_STATREG));
}
static inline bool meson_spicc_rxready(struct meson_spicc_device *spicc)
{
return FIELD_GET(SPICC_RH | SPICC_RR | SPICC_RF,
readl_relaxed(spicc->base + SPICC_STATREG));
}
static inline u32 meson_spicc_pull_data(struct meson_spicc_device *spicc)
{
unsigned int bytes = spicc->bytes_per_word;
unsigned int byte_shift = 0;
u32 data = 0;
u8 byte;
while (bytes--) {
byte = *spicc->tx_buf++;
data |= (byte & 0xff) << byte_shift;
byte_shift += 8;
}
spicc->tx_remain--;
return data;
}
static inline void meson_spicc_push_data(struct meson_spicc_device *spicc,
u32 data)
{
unsigned int bytes = spicc->bytes_per_word;
unsigned int byte_shift = 0;
u8 byte;
while (bytes--) {
byte = (data >> byte_shift) & 0xff;
*spicc->rx_buf++ = byte;
byte_shift += 8;
}
spicc->rx_remain--;
}
static inline void meson_spicc_rx(struct meson_spicc_device *spicc)
{
/* Empty RX FIFO */
while (spicc->rx_remain &&
meson_spicc_rxready(spicc))
meson_spicc_push_data(spicc,
readl_relaxed(spicc->base + SPICC_RXDATA));
}
static inline void meson_spicc_tx(struct meson_spicc_device *spicc)
{
/* Fill Up TX FIFO */
while (spicc->tx_remain &&
!meson_spicc_txfull(spicc))
writel_relaxed(meson_spicc_pull_data(spicc),
spicc->base + SPICC_TXDATA);
}
static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc)
{
unsigned int burst_len = min_t(unsigned int,
spicc->xfer_remain /
spicc->bytes_per_word,
spicc->data->fifo_size);
/* Setup Xfer variables */
spicc->tx_remain = burst_len;
spicc->rx_remain = burst_len;
spicc->xfer_remain -= burst_len * spicc->bytes_per_word;
/* Setup burst length */
writel_bits_relaxed(SPICC_BURSTLENGTH_MASK,
FIELD_PREP(SPICC_BURSTLENGTH_MASK,
burst_len - 1),
spicc->base + SPICC_CONREG);
/* Fill TX FIFO */
meson_spicc_tx(spicc);
}
static irqreturn_t meson_spicc_irq(int irq, void *data)
{
struct meson_spicc_device *spicc = (void *) data;
writel_bits_relaxed(SPICC_TC, SPICC_TC, spicc->base + SPICC_STATREG);
/* Empty RX FIFO */
meson_spicc_rx(spicc);
if (!spicc->xfer_remain) {
/* Disable all IRQs */
writel(0, spicc->base + SPICC_INTREG);
complete(&spicc->done);
return IRQ_HANDLED;
}
/* Setup burst */
meson_spicc_setup_burst(spicc);
/* Start burst */
writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
return IRQ_HANDLED;
}
static void meson_spicc_auto_io_delay(struct meson_spicc_device *spicc)
{
u32 div, hz;
u32 mi_delay, cap_delay;
u32 conf;
if (spicc->data->has_enhance_clk_div) {
div = FIELD_GET(SPICC_ENH_DATARATE_MASK,
readl_relaxed(spicc->base + SPICC_ENH_CTL0));
div++;
div <<= 1;
} else {
div = FIELD_GET(SPICC_DATARATE_MASK,
readl_relaxed(spicc->base + SPICC_CONREG));
div += 2;
div = 1 << div;
}
mi_delay = SPICC_MI_NO_DELAY;
cap_delay = SPICC_CAP_AHEAD_2_CYCLE;
hz = clk_get_rate(spicc->clk);
if (hz >= 100000000)
cap_delay = SPICC_CAP_DELAY_1_CYCLE;
else if (hz >= 80000000)
cap_delay = SPICC_CAP_NO_DELAY;
else if (hz >= 40000000)
cap_delay = SPICC_CAP_AHEAD_1_CYCLE;
else if (div >= 16)
mi_delay = SPICC_MI_DELAY_3_CYCLE;
else if (div >= 8)
mi_delay = SPICC_MI_DELAY_2_CYCLE;
else if (div >= 6)
mi_delay = SPICC_MI_DELAY_1_CYCLE;
conf = readl_relaxed(spicc->base + SPICC_TESTREG);
conf &= ~(SPICC_MO_DELAY_MASK | SPICC_MI_DELAY_MASK
| SPICC_MI_CAP_DELAY_MASK);
conf |= FIELD_PREP(SPICC_MI_DELAY_MASK, mi_delay);
conf |= FIELD_PREP(SPICC_MI_CAP_DELAY_MASK, cap_delay);
writel_relaxed(conf, spicc->base + SPICC_TESTREG);
}
static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc,
struct spi_transfer *xfer)
{
u32 conf, conf_orig;
/* Read original configuration */
conf = conf_orig = readl_relaxed(spicc->base + SPICC_CONREG);
/* Setup word width */
conf &= ~SPICC_BITLENGTH_MASK;
conf |= FIELD_PREP(SPICC_BITLENGTH_MASK,
(spicc->bytes_per_word << 3) - 1);
/* Ignore if unchanged */
if (conf != conf_orig)
writel_relaxed(conf, spicc->base + SPICC_CONREG);
clk_set_rate(spicc->clk, xfer->speed_hz);
meson_spicc_auto_io_delay(spicc);
writel_relaxed(0, spicc->base + SPICC_DMAREG);
}
static void meson_spicc_reset_fifo(struct meson_spicc_device *spicc)
{
if (spicc->data->has_oen)
writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO,
SPICC_ENH_MAIN_CLK_AO,
spicc->base + SPICC_ENH_CTL0);
writel_bits_relaxed(SPICC_FIFORST_W1_MASK, SPICC_FIFORST_W1_MASK,
spicc->base + SPICC_TESTREG);
while (meson_spicc_rxready(spicc))
readl_relaxed(spicc->base + SPICC_RXDATA);
if (spicc->data->has_oen)
writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO, 0,
spicc->base + SPICC_ENH_CTL0);
}
static int meson_spicc_transfer_one(struct spi_controller *host,
struct spi_device *spi,
struct spi_transfer *xfer)
{
struct meson_spicc_device *spicc = spi_controller_get_devdata(host);
uint64_t timeout;
/* Store current transfer */
spicc->xfer = xfer;
/* Setup transfer parameters */
spicc->tx_buf = (u8 *)xfer->tx_buf;
spicc->rx_buf = (u8 *)xfer->rx_buf;
spicc->xfer_remain = xfer->len;
/* Pre-calculate word size */
spicc->bytes_per_word =
DIV_ROUND_UP(spicc->xfer->bits_per_word, 8);
if (xfer->len % spicc->bytes_per_word)
return -EINVAL;
/* Setup transfer parameters */
meson_spicc_setup_xfer(spicc, xfer);
meson_spicc_reset_fifo(spicc);
/* Setup burst */
meson_spicc_setup_burst(spicc);
/* Setup wait for completion */
reinit_completion(&spicc->done);
/* For each byte we wait for 8 cycles of the SPI clock */
timeout = 8LL * MSEC_PER_SEC * xfer->len;
do_div(timeout, xfer->speed_hz);
/* Add 10us delay between each fifo bursts */
timeout += ((xfer->len >> 4) * 10) / MSEC_PER_SEC;
/* Increase it twice and add 200 ms tolerance */
timeout += timeout + 200;
/* Start burst */
writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
/* Enable interrupts */
writel_relaxed(SPICC_TC_EN, spicc->base + SPICC_INTREG);
if (!wait_for_completion_timeout(&spicc->done, msecs_to_jiffies(timeout)))
return -ETIMEDOUT;
return 0;
}
static int meson_spicc_prepare_message(struct spi_controller *host,
struct spi_message *message)
{
struct meson_spicc_device *spicc = spi_controller_get_devdata(host);
struct spi_device *spi = message->spi;
u32 conf = readl_relaxed(spicc->base + SPICC_CONREG) & SPICC_DATARATE_MASK;
/* Store current message */
spicc->message = message;
/* Enable Master */
conf |= SPICC_ENABLE;
conf |= SPICC_MODE_MASTER;
/* SMC = 0 */
/* Setup transfer mode */
if (spi->mode & SPI_CPOL)
conf |= SPICC_POL;
else
conf &= ~SPICC_POL;
if (!spicc->data->has_oen) {
if (spi->mode & SPI_CPOL) {
if (spicc->pins_idle_high)
pinctrl_select_state(spicc->pinctrl, spicc->pins_idle_high);
} else {
if (spicc->pins_idle_low)
pinctrl_select_state(spicc->pinctrl, spicc->pins_idle_low);
}
}
if (spi->mode & SPI_CPHA)
conf |= SPICC_PHA;
else
conf &= ~SPICC_PHA;
/* SSCTL = 0 */
if (spi->mode & SPI_CS_HIGH)
conf |= SPICC_SSPOL;
else
conf &= ~SPICC_SSPOL;
if (spi->mode & SPI_READY)
conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_LOWLEVEL);
else
conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_IGNORE);
/* Select CS */
conf |= FIELD_PREP(SPICC_CS_MASK, spi_get_chipselect(spi, 0));
/* Default 8bit word */
conf |= FIELD_PREP(SPICC_BITLENGTH_MASK, 8 - 1);
writel_relaxed(conf, spicc->base + SPICC_CONREG);
/* Setup no wait cycles by default */
writel_relaxed(0, spicc->base + SPICC_PERIODREG);
writel_bits_relaxed(SPICC_LBC_W1,
spi->mode & SPI_LOOP ? SPICC_LBC_W1 : 0,
spicc->base + SPICC_TESTREG);
return 0;
}
static int meson_spicc_unprepare_transfer(struct spi_controller *host)
{
struct meson_spicc_device *spicc = spi_controller_get_devdata(host);
u32 conf = readl_relaxed(spicc->base + SPICC_CONREG) & SPICC_DATARATE_MASK;
/* Disable all IRQs */
writel(0, spicc->base + SPICC_INTREG);
device_reset_optional(&spicc->pdev->dev);
/* Set default configuration, keeping datarate field */
writel_relaxed(conf, spicc->base + SPICC_CONREG);
if (!spicc->data->has_oen)
pinctrl_select_default_state(&spicc->pdev->dev);
return 0;
}
static int meson_spicc_setup(struct spi_device *spi)
{
if (!spi->controller_state)
spi->controller_state = spi_controller_get_devdata(spi->controller);
return 0;
}
static void meson_spicc_cleanup(struct spi_device *spi)
{
spi->controller_state = NULL;
}
/*
* The Clock Mux
* x-----------------x x------------x x------\
* |---| pow2 fixed div |---| pow2 div |----| |
* | x-----------------x x------------x | |
* src ---| | mux |-- out
* | x-----------------x x------------x | |
* |---| enh fixed div |---| enh div |0---| |
* x-----------------x x------------x x------/
*
* Clk path for GX series:
* src -> pow2 fixed div -> pow2 div -> out
*
* Clk path for AXG series:
* src -> pow2 fixed div -> pow2 div -> mux -> out
* src -> enh fixed div -> enh div -> mux -> out
*
* Clk path for G12A series:
* pclk -> pow2 fixed div -> pow2 div -> mux -> out
* pclk -> enh fixed div -> enh div -> mux -> out
*
* The pow2 divider is tied to the controller HW state, and the
* divider is only valid when the controller is initialized.
*
* A set of clock ops is added to make sure we don't read/set this
* clock rate while the controller is in an unknown state.
*/
static unsigned long meson_spicc_pow2_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
struct meson_spicc_device *spicc = pow2_clk_to_spicc(divider);
if (!spicc->host->cur_msg)
return 0;
return clk_divider_ops.recalc_rate(hw, parent_rate);
}
static int meson_spicc_pow2_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_divider *divider = to_clk_divider(hw);
struct meson_spicc_device *spicc = pow2_clk_to_spicc(divider);
if (!spicc->host->cur_msg)
return -EINVAL;
return clk_divider_ops.determine_rate(hw, req);
}
static int meson_spicc_pow2_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
struct meson_spicc_device *spicc = pow2_clk_to_spicc(divider);
if (!spicc->host->cur_msg)
return -EINVAL;
return clk_divider_ops.set_rate(hw, rate, parent_rate);
}
static const struct clk_ops meson_spicc_pow2_clk_ops = {
.recalc_rate = meson_spicc_pow2_recalc_rate,
.determine_rate = meson_spicc_pow2_determine_rate,
.set_rate = meson_spicc_pow2_set_rate,
};
static int meson_spicc_pow2_clk_init(struct meson_spicc_device *spicc)
{
struct device *dev = &spicc->pdev->dev;
struct clk_fixed_factor *pow2_fixed_div;
struct clk_init_data init;
struct clk *clk;
struct clk_parent_data parent_data[2];
char name[64];
memset(&init, 0, sizeof(init));
memset(&parent_data, 0, sizeof(parent_data));
init.parent_data = parent_data;
/* algorithm for pow2 div: rate = freq / 4 / (2 ^ N) */
pow2_fixed_div = devm_kzalloc(dev, sizeof(*pow2_fixed_div), GFP_KERNEL);
if (!pow2_fixed_div)
return -ENOMEM;
snprintf(name, sizeof(name), "%s#pow2_fixed_div", dev_name(dev));
init.name = name;
init.ops = &clk_fixed_factor_ops;
if (spicc->data->has_pclk) {
init.flags = CLK_SET_RATE_PARENT;
parent_data[0].hw = __clk_get_hw(spicc->pclk);
} else {
init.flags = 0;
parent_data[0].hw = __clk_get_hw(spicc->core);
}
init.num_parents = 1;
pow2_fixed_div->mult = 1;
pow2_fixed_div->div = 4;
pow2_fixed_div->hw.init = &init;
clk = devm_clk_register(dev, &pow2_fixed_div->hw);
if (WARN_ON(IS_ERR(clk)))
return PTR_ERR(clk);
snprintf(name, sizeof(name), "%s#pow2_div", dev_name(dev));
init.name = name;
init.ops = &meson_spicc_pow2_clk_ops;
/*
* Set NOCACHE here to make sure we read the actual HW value
* since we reset the HW after each transfer.
*/
init.flags = CLK_SET_RATE_PARENT | CLK_GET_RATE_NOCACHE;
parent_data[0].hw = &pow2_fixed_div->hw;
init.num_parents = 1;
spicc->pow2_div.shift = 16;
spicc->pow2_div.width = 3;
spicc->pow2_div.flags = CLK_DIVIDER_POWER_OF_TWO;
spicc->pow2_div.reg = spicc->base + SPICC_CONREG;
spicc->pow2_div.hw.init = &init;
spicc->clk = devm_clk_register(dev, &spicc->pow2_div.hw);
if (WARN_ON(IS_ERR(spicc->clk)))
return PTR_ERR(spicc->clk);
return 0;
}
static int meson_spicc_enh_clk_init(struct meson_spicc_device *spicc)
{
struct device *dev = &spicc->pdev->dev;
struct clk_fixed_factor *enh_fixed_div;
struct clk_divider *enh_div;
struct clk_mux *mux;
struct clk_init_data init;
struct clk *clk;
struct clk_parent_data parent_data[2];
char name[64];
memset(&init, 0, sizeof(init));
memset(&parent_data, 0, sizeof(parent_data));
init.parent_data = parent_data;
/* algorithm for enh div: rate = freq / 2 / (N + 1) */
enh_fixed_div = devm_kzalloc(dev, sizeof(*enh_fixed_div), GFP_KERNEL);
if (!enh_fixed_div)
return -ENOMEM;
snprintf(name, sizeof(name), "%s#enh_fixed_div", dev_name(dev));
init.name = name;
init.ops = &clk_fixed_factor_ops;
if (spicc->data->has_pclk) {
init.flags = CLK_SET_RATE_PARENT;
parent_data[0].hw = __clk_get_hw(spicc->pclk);
} else {
init.flags = 0;
parent_data[0].hw = __clk_get_hw(spicc->core);
}
init.num_parents = 1;
enh_fixed_div->mult = 1;
enh_fixed_div->div = 2;
enh_fixed_div->hw.init = &init;
clk = devm_clk_register(dev, &enh_fixed_div->hw);
if (WARN_ON(IS_ERR(clk)))
return PTR_ERR(clk);
enh_div = devm_kzalloc(dev, sizeof(*enh_div), GFP_KERNEL);
if (!enh_div)
return -ENOMEM;
snprintf(name, sizeof(name), "%s#enh_div", dev_name(dev));
init.name = name;
init.ops = &clk_divider_ops;
init.flags = CLK_SET_RATE_PARENT;
parent_data[0].hw = &enh_fixed_div->hw;
init.num_parents = 1;
enh_div->shift = 16;
enh_div->width = 8;
enh_div->reg = spicc->base + SPICC_ENH_CTL0;
enh_div->hw.init = &init;
clk = devm_clk_register(dev, &enh_div->hw);
if (WARN_ON(IS_ERR(clk)))
return PTR_ERR(clk);
mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
if (!mux)
return -ENOMEM;
snprintf(name, sizeof(name), "%s#sel", dev_name(dev));
init.name = name;
init.ops = &clk_mux_ops;
parent_data[0].hw = &spicc->pow2_div.hw;
parent_data[1].hw = &enh_div->hw;
init.num_parents = 2;
init.flags = CLK_SET_RATE_PARENT;
mux->mask = 0x1;
mux->shift = 24;
mux->reg = spicc->base + SPICC_ENH_CTL0;
mux->hw.init = &init;
spicc->clk = devm_clk_register(dev, &mux->hw);
if (WARN_ON(IS_ERR(spicc->clk)))
return PTR_ERR(spicc->clk);
return 0;
}
static int meson_spicc_probe(struct platform_device *pdev)
{
struct spi_controller *host;
struct meson_spicc_device *spicc;
int ret, irq;
host = spi_alloc_host(&pdev->dev, sizeof(*spicc));
if (!host) {
dev_err(&pdev->dev, "host allocation failed\n");
return -ENOMEM;
}
spicc = spi_controller_get_devdata(host);
spicc->host = host;
spicc->data = of_device_get_match_data(&pdev->dev);
if (!spicc->data) {
dev_err(&pdev->dev, "failed to get match data\n");
ret = -EINVAL;
goto out_host;
}
spicc->pdev = pdev;
platform_set_drvdata(pdev, spicc);
init_completion(&spicc->done);
spicc->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(spicc->base)) {
dev_err(&pdev->dev, "io resource mapping failed\n");
ret = PTR_ERR(spicc->base);
goto out_host;
}
/* Set master mode and enable controller */
writel_relaxed(SPICC_ENABLE | SPICC_MODE_MASTER,
spicc->base + SPICC_CONREG);
/* Disable all IRQs */
writel_relaxed(0, spicc->base + SPICC_INTREG);
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
ret = irq;
goto out_host;
}
ret = devm_request_irq(&pdev->dev, irq, meson_spicc_irq,
0, NULL, spicc);
if (ret) {
dev_err(&pdev->dev, "irq request failed\n");
goto out_host;
}
spicc->core = devm_clk_get_enabled(&pdev->dev, "core");
if (IS_ERR(spicc->core)) {
dev_err(&pdev->dev, "core clock request failed\n");
ret = PTR_ERR(spicc->core);
goto out_host;
}
if (spicc->data->has_pclk) {
spicc->pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
if (IS_ERR(spicc->pclk)) {
dev_err(&pdev->dev, "pclk clock request failed\n");
ret = PTR_ERR(spicc->pclk);
goto out_host;
}
}
spicc->pinctrl = devm_pinctrl_get(&pdev->dev);
if (IS_ERR(spicc->pinctrl)) {
ret = PTR_ERR(spicc->pinctrl);
goto out_host;
}
device_reset_optional(&pdev->dev);
host->num_chipselect = 4;
host->dev.of_node = pdev->dev.of_node;
host->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LOOP;
host->bits_per_word_mask = SPI_BPW_MASK(32) |
SPI_BPW_MASK(24) |
SPI_BPW_MASK(16) |
SPI_BPW_MASK(8);
host->flags = (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX);
host->min_speed_hz = spicc->data->min_speed_hz;
host->max_speed_hz = spicc->data->max_speed_hz;
host->setup = meson_spicc_setup;
host->cleanup = meson_spicc_cleanup;
host->prepare_message = meson_spicc_prepare_message;
host->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
host->transfer_one = meson_spicc_transfer_one;
host->use_gpio_descriptors = true;
meson_spicc_oen_enable(spicc);
ret = meson_spicc_pow2_clk_init(spicc);
if (ret) {
dev_err(&pdev->dev, "pow2 clock registration failed\n");
goto out_host;
}
if (spicc->data->has_enhance_clk_div) {
ret = meson_spicc_enh_clk_init(spicc);
if (ret) {
dev_err(&pdev->dev, "clock registration failed\n");
goto out_host;
}
}
ret = devm_spi_register_controller(&pdev->dev, host);
if (ret) {
dev_err(&pdev->dev, "spi registration failed\n");
goto out_host;
}
return 0;
out_host:
spi_controller_put(host);
return ret;
}
static void meson_spicc_remove(struct platform_device *pdev)
{
struct meson_spicc_device *spicc = platform_get_drvdata(pdev);
/* Disable SPI */
writel(0, spicc->base + SPICC_CONREG);
spi_controller_put(spicc->host);
}
static const struct meson_spicc_data meson_spicc_gx_data = {
.max_speed_hz = 30000000,
.min_speed_hz = 325000,
.fifo_size = 16,
};
static const struct meson_spicc_data meson_spicc_axg_data = {
.max_speed_hz = 80000000,
.min_speed_hz = 325000,
.fifo_size = 16,
.has_oen = true,
.has_enhance_clk_div = true,
};
static const struct meson_spicc_data meson_spicc_g12a_data = {
.max_speed_hz = 166666666,
.min_speed_hz = 50000,
.fifo_size = 15,
.has_oen = true,
.has_enhance_clk_div = true,
.has_pclk = true,
};
static const struct of_device_id meson_spicc_of_match[] = {
{
.compatible = "amlogic,meson-gx-spicc",
.data = &meson_spicc_gx_data,
},
{
.compatible = "amlogic,meson-axg-spicc",
.data = &meson_spicc_axg_data,
},
{
.compatible = "amlogic,meson-g12a-spicc",
.data = &meson_spicc_g12a_data,
},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, meson_spicc_of_match);
static struct platform_driver meson_spicc_driver = {
.probe = meson_spicc_probe,
.remove_new = meson_spicc_remove,
.driver = {
.name = "meson-spicc",
.of_match_table = of_match_ptr(meson_spicc_of_match),
},
};
module_platform_driver(meson_spicc_driver);
MODULE_DESCRIPTION("Meson SPI Communication Controller driver");
MODULE_AUTHOR("Neil Armstrong <[email protected]>");
MODULE_LICENSE("GPL");
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