From: Jassi Brar jaswinder.singh@linaro.org
Add driver for class of I2C controllers found on Socionext Synquacer platform.
Signed-off-by: Jassi Brar jaswinder.singh@linaro.org --- drivers/i2c/Kconfig | 7 + drivers/i2c/Makefile | 1 drivers/i2c/synquacer_i2c.c | 338 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 346 insertions(+) create mode 100644 drivers/i2c/synquacer_i2c.c
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index 57a4efb88e..ce0d796d09 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -455,6 +455,13 @@ config SYS_I2C_STM32F7 _ Optional clock stretching _ Software reset
+config SYS_I2C_SYNQUACER + bool "Socionext SynQuacer I2C controller" + depends on ARCH_SYNQUACER && DM_I2C + help + Support for Socionext Synquacer I2C controller. This I2C controller + will be used for RTC and LS-connector on DeveloperBox. + config SYS_I2C_TEGRA bool "NVIDIA Tegra internal I2C controller" depends on ARCH_TEGRA diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 8c9f1fcd8b..06a1150f03 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -43,6 +43,7 @@ obj-$(CONFIG_SYS_I2C_SANDBOX) += sandbox_i2c.o i2c-emul-uclass.o obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o obj-$(CONFIG_SYS_I2C_STM32F7) += stm32f7_i2c.o +obj-$(CONFIG_SYS_I2C_SYNQUACER) += synquacer_i2c.o obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o obj-$(CONFIG_SYS_I2C_UNIPHIER_F) += i2c-uniphier-f.o diff --git a/drivers/i2c/synquacer_i2c.c b/drivers/i2c/synquacer_i2c.c new file mode 100644 index 0000000000..6672d9435e --- /dev/null +++ b/drivers/i2c/synquacer_i2c.c @@ -0,0 +1,338 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + */ + +#include <dm/device_compat.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/io.h> +#include <linux/sizes.h> +#include <linux/types.h> +#include <dm.h> +#include <fdtdec.h> +#include <i2c.h> +#include <clk.h> + +#define REG_BSR 0x0 +#define REG_BCR 0x4 +#define REG_CCR 0x8 +#define REG_ADR 0xc +#define REG_DAR 0x10 +#define REG_CSR 0x14 +#define REG_FSR 0x18 +#define REG_BC2R 0x1c + +/* I2C register bit definitions */ +#define BSR_FBT BIT(0) // First Byte Transfer +#define BSR_GCA BIT(1) // General Call Address +#define BSR_AAS BIT(2) // Address as Slave +#define BSR_TRX BIT(3) // Transfer/Receive +#define BSR_LRB BIT(4) // Last Received Bit +#define BSR_AL BIT(5) // Arbitration Lost +#define BSR_RSC BIT(6) // Repeated Start Cond. +#define BSR_BB BIT(7) // Bus Busy + +#define BCR_INT BIT(0) // Interrupt +#define BCR_INTE BIT(1) // Interrupt Enable +#define BCR_GCAA BIT(2) // Gen. Call Access Ack. +#define BCR_ACK BIT(3) // Acknowledge +#define BCR_MSS BIT(4) // Master Slave Select +#define BCR_SCC BIT(5) // Start Condition Cont. +#define BCR_BEIE BIT(6) // Bus Error Int Enable +#define BCR_BER BIT(7) // Bus Error + +#define CCR_CS_MASK (0x1f) // CCR Clock Period Sel. +#define CCR_EN BIT(5) // Enable +#define CCR_FM BIT(6) // Speed Mode Select + +#define CSR_CS_MASK (0x3f) // CSR Clock Period Sel. + +#define BC2R_SCLL BIT(0) // SCL Low Drive +#define BC2R_SDAL BIT(1) // SDA Low Drive +#define BC2R_SCLS BIT(4) // SCL Status +#define BC2R_SDAS BIT(5) // SDA Status + +/* PCLK frequency */ +#define BUS_CLK_FR(rate) (((rate) / 20000000) + 1) + +#define I2C_CLK_DEF 62500000 + +/* STANDARD MODE frequency */ +#define CLK_MASTER_STD(rate) \ + DIV_ROUND_UP(DIV_ROUND_UP((rate), I2C_SPEED_STANDARD_RATE) - 2, 2) +/* FAST MODE frequency */ +#define CLK_MASTER_FAST(rate) \ + DIV_ROUND_UP((DIV_ROUND_UP((rate), I2C_SPEED_FAST_RATE) - 2) * 2, 3) + +/* (clkrate <= 18000000) */ +/* calculate the value of CS bits in CCR register on standard mode */ +#define CCR_CS_STD_MAX_18M(rate) \ + ((CLK_MASTER_STD(rate) - 65) \ + & CCR_CS_MASK) + +/* calculate the value of CS bits in CSR register on standard mode */ +#define CSR_CS_STD_MAX_18M(rate) 0x00 + +/* calculate the value of CS bits in CCR register on fast mode */ +#define CCR_CS_FAST_MAX_18M(rate) \ + ((CLK_MASTER_FAST(rate) - 1) \ + & CCR_CS_MASK) + +/* calculate the value of CS bits in CSR register on fast mode */ +#define CSR_CS_FAST_MAX_18M(rate) 0x00 + +/* (clkrate > 18000000) */ +/* calculate the value of CS bits in CCR register on standard mode */ +#define CCR_CS_STD_MIN_18M(rate) \ + ((CLK_MASTER_STD(rate) - 1) \ + & CCR_CS_MASK) + +/* calculate the value of CS bits in CSR register on standard mode */ +#define CSR_CS_STD_MIN_18M(rate) \ + (((CLK_MASTER_STD(rate) - 1) >> 5) \ + & CSR_CS_MASK) + +/* calculate the value of CS bits in CCR register on fast mode */ +#define CCR_CS_FAST_MIN_18M(rate) \ + ((CLK_MASTER_FAST(rate) - 1) \ + & CCR_CS_MASK) + +/* calculate the value of CS bits in CSR register on fast mode */ +#define CSR_CS_FAST_MIN_18M(rate) \ + (((CLK_MASTER_FAST(rate) - 1) >> 5) \ + & CSR_CS_MASK) + +/* min I2C clock frequency 14M */ +#define MIN_CLK_RATE (14 * 1000000) +/* max I2C clock frequency 200M */ +#define MAX_CLK_RATE (200 * 1000000) +/* I2C clock frequency 18M */ +#define CLK_RATE_18M (18 * 1000000) + +#define SPEED_FM 400 // Fast Mode +#define SPEED_SM 100 // Standard Mode + +DECLARE_GLOBAL_DATA_PTR; + +struct synquacer_i2c { + void __iomem *base; + unsigned long pclkrate; + unsigned long speed_khz; +}; + +static int wait_irq(struct udevice *dev) +{ + struct synquacer_i2c *i2c = dev_get_priv(dev); + int timeout = 500000; + + do { + if (readb(i2c->base + REG_BCR) & BCR_INT) + return 0; + } while (timeout--); + + pr_err("%s: timeout\n", __func__); + return -1; +} + +static int synquacer_i2c_xfer_start(struct synquacer_i2c *i2c, + int addr, int read) +{ + u8 bsr, bcr; + + writeb((addr << 1) | (read ? 1 : 0), i2c->base + REG_DAR); + + bsr = readb(i2c->base + REG_BSR); + bcr = readb(i2c->base + REG_BCR); + + if ((bsr & BSR_BB) && !(bcr & BCR_MSS)) + return -EBUSY; + + if (bsr & BSR_BB) { + writeb(bcr | BCR_SCC, i2c->base + REG_BCR); + } else { + if (bcr & BCR_MSS) + return -EAGAIN; + /* Start Condition + Enable Interrupts */ + writeb(bcr | BCR_MSS | BCR_INTE | BCR_BEIE, i2c->base + REG_BCR); + } + + udelay(100); + return 0; +} + +static int synquacer_i2c_xfer(struct udevice *bus, + struct i2c_msg *msg, int nmsgs) +{ + struct synquacer_i2c *i2c = dev_get_priv(bus); + u8 bsr, bcr; + int idx; + + for (; nmsgs > 0; nmsgs--, msg++) { + synquacer_i2c_xfer_start(i2c, msg->addr, msg->flags & I2C_M_RD); + if (wait_irq(bus)) + return -EREMOTEIO; + + bsr = readb(i2c->base + REG_BSR); + if (bsr & BSR_LRB) { + debug("%s: No ack received\n", __func__); + return -EREMOTEIO; + } + + idx = 0; + do { + bsr = readb(i2c->base + REG_BSR); + bcr = readb(i2c->base + REG_BCR); + if (bcr & BCR_BER) { + debug("%s: Bus error detected\n", __func__); + return -EREMOTEIO; + } + if ((bsr & BSR_AL) || !(bcr & BCR_MSS)) { + debug("%s: Arbitration lost\n", __func__); + return -EREMOTEIO; + } + + if (msg->flags & I2C_M_RD) { + bcr = BCR_MSS | BCR_INTE | BCR_BEIE; + if (idx < msg->len - 1) + bcr |= BCR_ACK; + writeb(bcr, i2c->base + REG_BCR); + if (wait_irq(bus)) + return -EREMOTEIO; + bsr = readb(i2c->base + REG_BSR); + if (!(bsr & BSR_FBT)) + msg->buf[idx++] = readb(i2c->base + REG_DAR); + } else { + writeb(msg->buf[idx++], i2c->base + REG_DAR); + bcr = BCR_MSS | BCR_INTE | BCR_BEIE; + writeb(bcr, i2c->base + REG_BCR); + if (wait_irq(bus)) + return -EREMOTEIO; + bsr = readb(i2c->base + REG_BSR); + if (bsr & BSR_LRB) { + debug("%s: no ack\n", __func__); + return -EREMOTEIO; + } + } + } while (idx < msg->len); + } + + /* Force bus state to idle, terminating any ongoing transfer */ + writeb(0, i2c->base + REG_BCR); + udelay(100); + + return 0; +} + +static void synquacer_i2c_hw_reset(struct synquacer_i2c *i2c) +{ + /* Disable clock */ + writeb(0, i2c->base + REG_CCR); + writeb(0, i2c->base + REG_CSR); + + /* Set own Address */ + writeb(0, i2c->base + REG_ADR); + + /* Set PCLK frequency */ + writeb(BUS_CLK_FR(i2c->pclkrate), i2c->base + REG_FSR); + + /* clear IRQ (INT=0, BER=0), Interrupt Disable */ + writeb(0, i2c->base + REG_BCR); + writeb(0, i2c->base + REG_BC2R); +} + +static int synquacer_i2c_get_bus_speed(struct udevice *bus) +{ + struct synquacer_i2c *i2c = dev_get_priv(bus); + + return i2c->speed_khz * 1000; +} + +static int synquacer_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) +{ + struct synquacer_i2c *i2c = dev_get_priv(bus); + u32 rt = i2c->pclkrate; + u8 ccr_cs, csr_cs; + + /* Set PCLK frequency */ + writeb(BUS_CLK_FR(i2c->pclkrate), i2c->base + REG_FSR); + + if (speed >= SPEED_FM * 1000) { + i2c->speed_khz = SPEED_FM; + if (i2c->pclkrate <= CLK_RATE_18M) { + ccr_cs = CCR_CS_FAST_MAX_18M(rt); + csr_cs = CSR_CS_FAST_MAX_18M(rt); + } else { + ccr_cs = CCR_CS_FAST_MIN_18M(rt); + csr_cs = CSR_CS_FAST_MIN_18M(rt); + } + + /* Set Clock and enable, Set fast mode */ + writeb(ccr_cs | CCR_FM | CCR_EN, i2c->base + REG_CCR); + writeb(csr_cs, i2c->base + REG_CSR); + } else { + i2c->speed_khz = SPEED_SM; + if (i2c->pclkrate <= CLK_RATE_18M) { + ccr_cs = CCR_CS_STD_MAX_18M(rt); + csr_cs = CSR_CS_STD_MAX_18M(rt); + } else { + ccr_cs = CCR_CS_STD_MIN_18M(rt); + csr_cs = CSR_CS_STD_MIN_18M(rt); + } + + /* Set Clock and enable, Set standard mode */ + writeb(ccr_cs | CCR_EN, i2c->base + REG_CCR); + writeb(csr_cs, i2c->base + REG_CSR); + } + + return 0; +} + +static int synquacer_i2c_of_to_plat(struct udevice *bus) +{ + struct synquacer_i2c *priv = dev_get_priv(bus); + struct clk ck; + int ret; + + ret = clk_get_by_index(bus, 0, &ck); + if (ret < 0) { + priv->pclkrate = I2C_CLK_DEF; + } else { + clk_enable(&ck); + priv->pclkrate = clk_get_rate(&ck); + } + + return 0; +} + +static int synquacer_i2c_probe(struct udevice *bus) +{ + struct synquacer_i2c *i2c = dev_get_priv(bus); + + i2c->base = dev_read_addr_ptr(bus); + synquacer_i2c_hw_reset(i2c); + synquacer_i2c_set_bus_speed(bus, 400000); /* set default speed */ + return 0; +} + +static const struct dm_i2c_ops synquacer_i2c_ops = { + .xfer = synquacer_i2c_xfer, + .set_bus_speed = synquacer_i2c_set_bus_speed, + .get_bus_speed = synquacer_i2c_get_bus_speed, +}; + +static const struct udevice_id synquacer_i2c_ids[] = { + { + .compatible = "socionext,synquacer-i2c", + }, + { } +}; + +U_BOOT_DRIVER(sni_synquacer_i2c) = { + .name = "sni_synquacer_i2c", + .id = UCLASS_I2C, + .of_match = synquacer_i2c_ids, + .of_to_plat = synquacer_i2c_of_to_plat, + .probe = synquacer_i2c_probe, + .priv_auto = sizeof(struct synquacer_i2c), + .ops = &synquacer_i2c_ops, +};