Add compatible for the integration of the same DB8500 IP block into the Mobileye EyeQ5 platform. Two quirks are present: - The memory bus only supports 32-bit accesses. Avoid writeb() and readb() by introducing helper functions that fallback to writel() and readl(). - A register must be configured for the I2C speed mode; it is located in a shared register region called OLB. We access that memory region using a syscon & regmap that gets passed as a phandle (mobileye,olb). A two-bit enum per controller is written into the register; that requires us to know the global index of the I2C controller (cell arg to the mobileye,olb phandle). We add #include <linux/mfd/syscon.h> and <linux/regmap.h> and sort headers. Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx> --- drivers/i2c/busses/i2c-nomadik.c | 95 +++++++++++++++++++++++++++++++++++----- 1 file changed, 84 insertions(+), 11 deletions(-) diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c index 2d3247979e45..e9a77377add4 100644 --- a/drivers/i2c/busses/i2c-nomadik.c +++ b/drivers/i2c/busses/i2c-nomadik.c @@ -6,22 +6,30 @@ * I2C master mode controller driver, used in Nomadik 8815 * and Ux500 platforms. * + * The Mobileye EyeQ5 platform is also supported; it uses + * the same Ux500/DB8500 IP block with two quirks: + * - The memory bus only supports 32-bit accesses. + * - A register must be configured for the I2C speed mode; + * it is located in a shared register region called OLB. + * * Author: Srinidhi Kasagar <srinidhi.kasagar@xxxxxxxxxxxxxx> * Author: Sachin Verma <sachin.verma@xxxxxx> */ +#include <linux/amba/bus.h> #include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/i2c.h> #include <linux/init.h> -#include <linux/module.h> -#include <linux/amba/bus.h> -#include <linux/slab.h> #include <linux/interrupt.h> -#include <linux/i2c.h> -#include <linux/err.h> -#include <linux/clk.h> #include <linux/io.h> -#include <linux/pm_runtime.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <linux/slab.h> #define DRIVER_NAME "nmk-i2c" @@ -110,6 +118,10 @@ enum i2c_freq_mode { I2C_FREQ_MODE_FAST_PLUS, /* up to 1 Mb/s */ }; +/* Mobileye EyeQ5 offset into a shared register region (called OLB) */ +#define NMK_I2C_EYEQ5_OLB_IOCR2 0x0B8 +#define NMK_I2C_EYEQ5_OLB_IOCR2_SHIFT(id) (4 + 2 * (id)) + /** * struct i2c_vendor_data - per-vendor variations * @has_mtdws: variant has the MTDWS bit @@ -168,6 +180,7 @@ struct i2c_nmk_client { * @xfer_wq: xfer done wait queue. * @xfer_done: xfer done boolean. * @result: controller propogated result. + * @has_32b_bus: controller is on a bus that only supports 32-bit accesses. */ struct nmk_i2c_dev { struct i2c_vendor_data *vendor; @@ -186,6 +199,7 @@ struct nmk_i2c_dev { struct wait_queue_head xfer_wq; bool xfer_done; int result; + bool has_32b_bus; }; /* controller's abort causes */ @@ -209,6 +223,24 @@ static inline void i2c_clr_bit(void __iomem *reg, u32 mask) writel(readl(reg) & ~mask, reg); } +static inline u8 nmk_i2c_readb(const struct nmk_i2c_dev *priv, + unsigned long reg) +{ + if (priv->has_32b_bus) + return readl(priv->virtbase + reg); + else + return readb(priv->virtbase + reg); +} + +static inline void nmk_i2c_writeb(const struct nmk_i2c_dev *priv, u32 val, + unsigned long reg) +{ + if (priv->has_32b_bus) + writel(val, priv->virtbase + reg); + else + writeb(val, priv->virtbase + reg); +} + /** * flush_i2c_fifo() - This function flushes the I2C FIFO * @priv: private data of I2C Driver @@ -514,7 +546,7 @@ static void fill_tx_fifo(struct nmk_i2c_dev *priv, int no_bytes) (priv->cli.count != 0); count--) { /* write to the Tx FIFO */ - writeb(*priv->cli.buffer, priv->virtbase + I2C_TFR); + nmk_i2c_writeb(priv, *priv->cli.buffer, I2C_TFR); priv->cli.buffer++; priv->cli.count--; priv->cli.xfer_bytes++; @@ -783,7 +815,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg) case I2C_IT_RXFNF: for (count = rft; count > 0; count--) { /* Read the Rx FIFO */ - *priv->cli.buffer = readb(priv->virtbase + I2C_RFR); + *priv->cli.buffer = nmk_i2c_readb(priv, I2C_RFR); priv->cli.buffer++; } priv->cli.count -= rft; @@ -793,7 +825,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg) /* Rx FIFO full */ case I2C_IT_RXFF: for (count = MAX_I2C_FIFO_THRESHOLD; count > 0; count--) { - *priv->cli.buffer = readb(priv->virtbase + I2C_RFR); + *priv->cli.buffer = nmk_i2c_readb(priv, I2C_RFR); priv->cli.buffer++; } priv->cli.count -= MAX_I2C_FIFO_THRESHOLD; @@ -809,7 +841,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg) if (priv->cli.count == 0) break; *priv->cli.buffer = - readb(priv->virtbase + I2C_RFR); + nmk_i2c_readb(priv, I2C_RFR); priv->cli.buffer++; priv->cli.count--; priv->cli.xfer_bytes++; @@ -985,6 +1017,38 @@ static void nmk_i2c_of_probe(struct device_node *np, priv->timeout_usecs = 200 * USEC_PER_MSEC; } +static int nmk_i2c_eyeq5_probe(struct nmk_i2c_dev *priv) +{ + struct device *dev = &priv->adev->dev; + struct device_node *np = dev->of_node; + unsigned int shift, speed_mode; + struct regmap *olb; + unsigned int id; + + priv->has_32b_bus = true; + + olb = syscon_regmap_lookup_by_phandle_args(np, "mobileye,olb", 1, &id); + if (IS_ERR_OR_NULL(olb)) { + if (!olb) + olb = ERR_PTR(-ENOENT); + return dev_err_probe(dev, PTR_ERR(olb), + "failed OLB lookup: %lu\n", PTR_ERR(olb)); + } + + if (priv->clk_freq <= 400000) + speed_mode = 0b00; + else if (priv->clk_freq <= 1000000) + speed_mode = 0b01; + else + speed_mode = 0b10; + + shift = NMK_I2C_EYEQ5_OLB_IOCR2_SHIFT(id); + regmap_update_bits(olb, NMK_I2C_EYEQ5_OLB_IOCR2, + 0b11 << shift, speed_mode << shift); + + return 0; +} + static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id) { int ret = 0; @@ -1001,8 +1065,17 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id) priv->vendor = vendor; priv->adev = adev; + priv->has_32b_bus = false; nmk_i2c_of_probe(np, priv); + if (of_device_is_compatible(np, "mobileye,eyeq5-i2c")) { + ret = nmk_i2c_eyeq5_probe(priv); + if (ret) { + dev_info(dev, "%s: %d: %d\n", __func__, __LINE__, ret); + return ret; + } + } + if (priv->tft > max_fifo_threshold) { dev_warn(dev, "requested TX FIFO threshold %u, adjusted down to %u\n", priv->tft, max_fifo_threshold); -- 2.44.0