--- /dev/null
+/*
+ * Copyright (C) 2017 Spreadtrum Communications Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/hwspinlock.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/sizes.h>
+
+/* Registers definitions for ADI controller */
+#define REG_ADI_CTRL0 0x4
+#define REG_ADI_CHN_PRIL 0x8
+#define REG_ADI_CHN_PRIH 0xc
+#define REG_ADI_INT_EN 0x10
+#define REG_ADI_INT_RAW 0x14
+#define REG_ADI_INT_MASK 0x18
+#define REG_ADI_INT_CLR 0x1c
+#define REG_ADI_GSSI_CFG0 0x20
+#define REG_ADI_GSSI_CFG1 0x24
+#define REG_ADI_RD_CMD 0x28
+#define REG_ADI_RD_DATA 0x2c
+#define REG_ADI_ARM_FIFO_STS 0x30
+#define REG_ADI_STS 0x34
+#define REG_ADI_EVT_FIFO_STS 0x38
+#define REG_ADI_ARM_CMD_STS 0x3c
+#define REG_ADI_CHN_EN 0x40
+#define REG_ADI_CHN_ADDR(id) (0x44 + (id - 2) * 4)
+#define REG_ADI_CHN_EN1 0x20c
+
+/* Bits definitions for register REG_ADI_GSSI_CFG0 */
+#define BIT_CLK_ALL_ON BIT(30)
+
+/* Bits definitions for register REG_ADI_RD_DATA */
+#define BIT_RD_CMD_BUSY BIT(31)
+#define RD_ADDR_SHIFT 16
+#define RD_VALUE_MASK GENMASK(15, 0)
+#define RD_ADDR_MASK GENMASK(30, 16)
+
+/* Bits definitions for register REG_ADI_ARM_FIFO_STS */
+#define BIT_FIFO_FULL BIT(11)
+#define BIT_FIFO_EMPTY BIT(10)
+
+/*
+ * ADI slave devices include RTC, ADC, regulator, charger, thermal and so on.
+ * The slave devices address offset is always 0x8000 and size is 4K.
+ */
+#define ADI_SLAVE_ADDR_SIZE SZ_4K
+#define ADI_SLAVE_OFFSET 0x8000
+
+/* Timeout (ms) for the trylock of hardware spinlocks */
+#define ADI_HWSPINLOCK_TIMEOUT 5000
+/*
+ * ADI controller has 50 channels including 2 software channels
+ * and 48 hardware channels.
+ */
+#define ADI_HW_CHNS 50
+
+#define ADI_FIFO_DRAIN_TIMEOUT 1000
+#define ADI_READ_TIMEOUT 2000
+#define REG_ADDR_LOW_MASK GENMASK(11, 0)
+
+struct sprd_adi {
+ struct spi_controller *ctlr;
+ struct device *dev;
+ void __iomem *base;
+ struct hwspinlock *hwlock;
+ unsigned long slave_vbase;
+ unsigned long slave_pbase;
+};
+
+static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
+{
+ if (paddr < sadi->slave_pbase || paddr >
+ (sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
+ dev_err(sadi->dev,
+ "slave physical address is incorrect, addr = 0x%x\n",
+ paddr);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
+{
+ return (paddr - sadi->slave_pbase + sadi->slave_vbase);
+}
+
+static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
+{
+ u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
+ u32 sts;
+
+ do {
+ sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
+ if (sts & BIT_FIFO_EMPTY)
+ break;
+
+ cpu_relax();
+ } while (--timeout);
+
+ if (timeout == 0) {
+ dev_err(sadi->dev, "drain write fifo timeout\n");
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
+{
+ return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
+}
+
+static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
+{
+ int read_timeout = ADI_READ_TIMEOUT;
+ u32 val, rd_addr;
+
+ /*
+ * Set the physical register address need to read into RD_CMD register,
+ * then ADI controller will start to transfer automatically.
+ */
+ writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);
+
+ /*
+ * Wait read operation complete, the BIT_RD_CMD_BUSY will be set
+ * simultaneously when writing read command to register, and the
+ * BIT_RD_CMD_BUSY will be cleared after the read operation is
+ * completed.
+ */
+ do {
+ val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
+ if (!(val & BIT_RD_CMD_BUSY))
+ break;
+
+ cpu_relax();
+ } while (--read_timeout);
+
+ if (read_timeout == 0) {
+ dev_err(sadi->dev, "ADI read timeout\n");
+ return -EBUSY;
+ }
+
+ /*
+ * The return value includes data and read register address, from bit 0
+ * to bit 15 are data, and from bit 16 to bit 30 are read register
+ * address. Then we can check the returned register address to validate
+ * data.
+ */
+ rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;
+
+ if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
+ dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
+ reg_paddr, val);
+ return -EIO;
+ }
+
+ *read_val = val & RD_VALUE_MASK;
+ return 0;
+}
+
+static int sprd_adi_write(struct sprd_adi *sadi, unsigned long reg, u32 val)
+{
+ u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
+ int ret;
+
+ ret = sprd_adi_drain_fifo(sadi);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * we should wait for write fifo is empty before writing data to PMIC
+ * registers.
+ */
+ do {
+ if (!sprd_adi_fifo_is_full(sadi)) {
+ writel_relaxed(val, (void __iomem *)reg);
+ break;
+ }
+
+ cpu_relax();
+ } while (--timeout);
+
+ if (timeout == 0) {
+ dev_err(sadi->dev, "write fifo is full\n");
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+static int sprd_adi_transfer_one(struct spi_controller *ctlr,
+ struct spi_device *spi_dev,
+ struct spi_transfer *t)
+{
+ struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
+ unsigned long flags, virt_reg;
+ u32 phy_reg, val;
+ int ret;
+
+ if (t->rx_buf) {
+ phy_reg = *(u32 *)t->rx_buf + sadi->slave_pbase;
+
+ ret = sprd_adi_check_paddr(sadi, phy_reg);
+ if (ret)
+ return ret;
+
+ ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
+ ADI_HWSPINLOCK_TIMEOUT,
+ &flags);
+ if (ret) {
+ dev_err(sadi->dev, "get the hw lock failed\n");
+ return ret;
+ }
+
+ ret = sprd_adi_read(sadi, phy_reg, &val);
+ hwspin_unlock_irqrestore(sadi->hwlock, &flags);
+ if (ret)
+ return ret;
+
+ *(u32 *)t->rx_buf = val;
+ } else if (t->tx_buf) {
+ u32 *p = (u32 *)t->tx_buf;
+
+ /*
+ * Get the physical register address need to write and convert
+ * the physical address to virtual address. Since we need
+ * virtual register address to write.
+ */
+ phy_reg = *p++ + sadi->slave_pbase;
+ ret = sprd_adi_check_paddr(sadi, phy_reg);
+ if (ret)
+ return ret;
+
+ virt_reg = sprd_adi_to_vaddr(sadi, phy_reg);
+ val = *p;
+
+ ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
+ ADI_HWSPINLOCK_TIMEOUT,
+ &flags);
+ if (ret) {
+ dev_err(sadi->dev, "get the hw lock failed\n");
+ return ret;
+ }
+
+ ret = sprd_adi_write(sadi, virt_reg, val);
+ hwspin_unlock_irqrestore(sadi->hwlock, &flags);
+ if (ret)
+ return ret;
+ } else {
+ dev_err(sadi->dev, "no buffer for transfer\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void sprd_adi_hw_init(struct sprd_adi *sadi)
+{
+ struct device_node *np = sadi->dev->of_node;
+ int i, size, chn_cnt;
+ const __be32 *list;
+ u32 tmp;
+
+ /* Address bits select default 12 bits */
+ writel_relaxed(0, sadi->base + REG_ADI_CTRL0);
+
+ /* Set all channels as default priority */
+ writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
+ writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);
+
+ /* Set clock auto gate mode */
+ tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
+ tmp &= ~BIT_CLK_ALL_ON;
+ writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);
+
+ /* Set hardware channels setting */
+ list = of_get_property(np, "sprd,hw-channels", &size);
+ if (!size || !list) {
+ dev_info(sadi->dev, "no hw channels setting in node\n");
+ return;
+ }
+
+ chn_cnt = size / 8;
+ for (i = 0; i < chn_cnt; i++) {
+ u32 value;
+ u32 chn_id = be32_to_cpu(*list++);
+ u32 chn_config = be32_to_cpu(*list++);
+
+ /* Channel 0 and 1 are software channels */
+ if (chn_id < 2)
+ continue;
+
+ writel_relaxed(chn_config, sadi->base +
+ REG_ADI_CHN_ADDR(chn_id));
+
+ if (chn_id < 31) {
+ value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
+ value |= BIT(chn_id);
+ writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
+ } else if (chn_id < ADI_HW_CHNS) {
+ value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
+ value |= BIT(chn_id - 32);
+ writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
+ }
+ }
+}
+
+static int sprd_adi_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct spi_controller *ctlr;
+ struct sprd_adi *sadi;
+ struct resource *res;
+ u32 num_chipselect;
+ int ret;
+
+ if (!np) {
+ dev_err(&pdev->dev, "can not find the adi bus node\n");
+ return -ENODEV;
+ }
+
+ pdev->id = of_alias_get_id(np, "spi");
+ num_chipselect = of_get_child_count(np);
+
+ ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
+ if (!ctlr)
+ return -ENOMEM;
+
+ dev_set_drvdata(&pdev->dev, ctlr);
+ sadi = spi_controller_get_devdata(ctlr);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ sadi->base = devm_ioremap_resource(&pdev->dev, res);
+ if (!sadi->base) {
+ ret = -ENOMEM;
+ goto put_ctlr;
+ }
+
+ sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
+ sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
+ sadi->ctlr = ctlr;
+ sadi->dev = &pdev->dev;
+ ret = of_hwspin_lock_get_id(np, 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "can not get the hardware spinlock\n");
+ goto put_ctlr;
+ }
+
+ sadi->hwlock = hwspin_lock_request_specific(ret);
+ if (!sadi->hwlock) {
+ ret = -ENXIO;
+ goto put_ctlr;
+ }
+
+ sprd_adi_hw_init(sadi);
+
+ ctlr->dev.of_node = pdev->dev.of_node;
+ ctlr->bus_num = pdev->id;
+ ctlr->num_chipselect = num_chipselect;
+ ctlr->flags = SPI_MASTER_HALF_DUPLEX;
+ ctlr->bits_per_word_mask = 0;
+ ctlr->transfer_one = sprd_adi_transfer_one;
+
+ ret = devm_spi_register_controller(&pdev->dev, ctlr);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register SPI controller\n");
+ goto free_hwlock;
+ }
+
+ return 0;
+
+free_hwlock:
+ hwspin_lock_free(sadi->hwlock);
+put_ctlr:
+ spi_controller_put(ctlr);
+ return ret;
+}
+
+static int sprd_adi_remove(struct platform_device *pdev)
+{
+ struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
+ struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
+
+ hwspin_lock_free(sadi->hwlock);
+ return 0;
+}
+
+static const struct of_device_id sprd_adi_of_match[] = {
+ {
+ .compatible = "sprd,sc9860-adi",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, sprd_adi_of_match);
+
+static struct platform_driver sprd_adi_driver = {
+ .driver = {
+ .name = "sprd-adi",
+ .owner = THIS_MODULE,
+ .of_match_table = sprd_adi_of_match,
+ },
+ .probe = sprd_adi_probe,
+ .remove = sprd_adi_remove,
+};
+module_platform_driver(sprd_adi_driver);
+
+MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
+MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-rpi.git / commitdiff