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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/spi/spi-meson-spicc.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/spi/spi-meson-spicc.c')
-rw-r--r--drivers/spi/spi-meson-spicc.c978
1 files changed, 978 insertions, 0 deletions
diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c
new file mode 100644
index 0000000000..43d134f4b4
--- /dev/null
+++ b/drivers/spi/spi-meson-spicc.c
@@ -0,0 +1,978 @@
+/*
+ * Driver for Amlogic Meson SPI communication controller (SPICC)
+ *
+ * Copyright (C) BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * 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_master *master;
+ 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_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct meson_spicc_device *spicc = spi_master_get_devdata(master);
+ 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_master *master,
+ struct spi_message *message)
+{
+ struct meson_spicc_device *spicc = spi_master_get_devdata(master);
+ 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, 0, spicc->base + SPICC_TESTREG);
+
+ return 0;
+}
+
+static int meson_spicc_unprepare_transfer(struct spi_master *master)
+{
+ struct meson_spicc_device *spicc = spi_master_get_devdata(master);
+ 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_master_get_devdata(spi->master);
+
+ 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->master->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->master->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->master->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;
+ init.flags = 0;
+ if (spicc->data->has_pclk)
+ parent_data[0].hw = __clk_get_hw(spicc->pclk);
+ else
+ 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;
+ init.flags = 0;
+ if (spicc->data->has_pclk)
+ parent_data[0].hw = __clk_get_hw(spicc->pclk);
+ else
+ 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_master *master;
+ struct meson_spicc_device *spicc;
+ int ret, irq;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*spicc));
+ if (!master) {
+ dev_err(&pdev->dev, "master allocation failed\n");
+ return -ENOMEM;
+ }
+ spicc = spi_master_get_devdata(master);
+ spicc->master = master;
+
+ 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_master;
+ }
+
+ 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_master;
+ }
+
+ /* 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_master;
+ }
+
+ 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_master;
+ }
+
+ spicc->core = devm_clk_get(&pdev->dev, "core");
+ if (IS_ERR(spicc->core)) {
+ dev_err(&pdev->dev, "core clock request failed\n");
+ ret = PTR_ERR(spicc->core);
+ goto out_master;
+ }
+
+ if (spicc->data->has_pclk) {
+ spicc->pclk = devm_clk_get(&pdev->dev, "pclk");
+ if (IS_ERR(spicc->pclk)) {
+ dev_err(&pdev->dev, "pclk clock request failed\n");
+ ret = PTR_ERR(spicc->pclk);
+ goto out_master;
+ }
+ }
+
+ ret = clk_prepare_enable(spicc->core);
+ if (ret) {
+ dev_err(&pdev->dev, "core clock enable failed\n");
+ goto out_master;
+ }
+
+ ret = clk_prepare_enable(spicc->pclk);
+ if (ret) {
+ dev_err(&pdev->dev, "pclk clock enable failed\n");
+ goto out_core_clk;
+ }
+
+ spicc->pinctrl = devm_pinctrl_get(&pdev->dev);
+ if (IS_ERR(spicc->pinctrl)) {
+ ret = PTR_ERR(spicc->pinctrl);
+ goto out_clk;
+ }
+
+ device_reset_optional(&pdev->dev);
+
+ master->num_chipselect = 4;
+ master->dev.of_node = pdev->dev.of_node;
+ master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH;
+ master->bits_per_word_mask = SPI_BPW_MASK(32) |
+ SPI_BPW_MASK(24) |
+ SPI_BPW_MASK(16) |
+ SPI_BPW_MASK(8);
+ master->flags = (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX);
+ master->min_speed_hz = spicc->data->min_speed_hz;
+ master->max_speed_hz = spicc->data->max_speed_hz;
+ master->setup = meson_spicc_setup;
+ master->cleanup = meson_spicc_cleanup;
+ master->prepare_message = meson_spicc_prepare_message;
+ master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
+ master->transfer_one = meson_spicc_transfer_one;
+ master->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_clk;
+ }
+
+ 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_clk;
+ }
+ }
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (ret) {
+ dev_err(&pdev->dev, "spi master registration failed\n");
+ goto out_clk;
+ }
+
+ return 0;
+
+out_clk:
+ clk_disable_unprepare(spicc->pclk);
+
+out_core_clk:
+ clk_disable_unprepare(spicc->core);
+
+out_master:
+ spi_master_put(master);
+
+ 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);
+
+ clk_disable_unprepare(spicc->core);
+ clk_disable_unprepare(spicc->pclk);
+
+ spi_master_put(spicc->master);
+}
+
+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 <narmstrong@baylibre.com>");
+MODULE_LICENSE("GPL");