i2c: qcom-geni: add desc struct to prepare support for I2C Master Hub variant

The I2C Master Hub is a stripped down version of the GENI Serial Engine
QUP Wrapper Controller but only supporting I2C serial engines without
DMA support.

Those I2C serial engines variants have some requirements:
- a separate "core" clock
- doesn't support DMA, thus no memory interconnect path
- fixed FIFO size not discoverable in the HW_PARAM_0 register

Add a desc struct specifying all those requirements which will be used in
a next change when adding the I2C Master Hub serial engine compatible.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 84a77512614d9fbdd9462cf5644426af3d4b2de4..75dd0718c5a12781a73154b47f5117d1f197f7c9 100644 (file)
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -88,6 +88,7 @@ struct geni_i2c_dev {
        int cur_wr;
        int cur_rd;
        spinlock_t lock;
+       struct clk *core_clk;
        u32 clk_freq_out;
        const struct geni_i2c_clk_fld *clk_fld;
        int suspended;
@@ -100,6 +101,13 @@ struct geni_i2c_dev {
        bool abort_done;
 };
 
+struct geni_i2c_desc {
+       bool has_core_clk;
+       char *icc_ddr;
+       bool no_dma_support;
+       unsigned int tx_fifo_depth;
+};
+
 struct geni_i2c_err_log {
        int err;
        const char *msg;
@@ -764,6 +772,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
        u32 proto, tx_depth, fifo_disable;
        int ret;
        struct device *dev = &pdev->dev;
+       const struct geni_i2c_desc *desc = NULL;
 
        gi2c = devm_kzalloc(dev, sizeof(*gi2c), GFP_KERNEL);
        if (!gi2c)
@@ -776,6 +785,14 @@ static int geni_i2c_probe(struct platform_device *pdev)
        if (IS_ERR(gi2c->se.base))
                return PTR_ERR(gi2c->se.base);
 
+       desc = device_get_match_data(&pdev->dev);
+
+       if (desc && desc->has_core_clk) {
+               gi2c->core_clk = devm_clk_get(dev, "core");
+               if (IS_ERR(gi2c->core_clk))
+                       return PTR_ERR(gi2c->core_clk);
+       }
+
        gi2c->se.clk = devm_clk_get(dev, "se");
        if (IS_ERR(gi2c->se.clk) && !has_acpi_companion(dev))
                return PTR_ERR(gi2c->se.clk);
@@ -819,7 +836,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
        gi2c->adap.dev.of_node = dev->of_node;
        strscpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));
 
-       ret = geni_icc_get(&gi2c->se, "qup-memory");
+       ret = geni_icc_get(&gi2c->se, desc ? desc->icc_ddr : "qup-memory");
        if (ret)
                return ret;
        /*
@@ -829,12 +846,17 @@ static int geni_i2c_probe(struct platform_device *pdev)
         */
        gi2c->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
        gi2c->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
-       gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);
+       if (!desc || desc->icc_ddr)
+               gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);
 
        ret = geni_icc_set_bw(&gi2c->se);
        if (ret)
                return ret;
 
+       ret = clk_prepare_enable(gi2c->core_clk);
+       if (ret)
+               return ret;
+
        ret = geni_se_resources_on(&gi2c->se);
        if (ret) {
                dev_err(dev, "Error turning on resources %d\n", ret);
@@ -844,10 +866,15 @@ static int geni_i2c_probe(struct platform_device *pdev)
        if (proto != GENI_SE_I2C) {
                dev_err(dev, "Invalid proto %d\n", proto);
                geni_se_resources_off(&gi2c->se);
+               clk_disable_unprepare(gi2c->core_clk);
                return -ENXIO;
        }
 
-       fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
+       if (desc && desc->no_dma_support)
+               fifo_disable = false;
+       else
+               fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
+
        if (fifo_disable) {
                /* FIFO is disabled, so we can only use GPI DMA */
                gi2c->gpi_mode = true;
@@ -859,6 +886,16 @@ static int geni_i2c_probe(struct platform_device *pdev)
        } else {
                gi2c->gpi_mode = false;
                tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
+
+               /* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
+               if (!tx_depth && desc)
+                       tx_depth = desc->tx_fifo_depth;
+
+               if (!tx_depth) {
+                       dev_err(dev, "Invalid TX FIFO depth\n");
+                       return -EINVAL;
+               }
+
                gi2c->tx_wm = tx_depth - 1;
                geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
                geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
@@ -867,6 +904,7 @@ static int geni_i2c_probe(struct platform_device *pdev)
                dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
        }
 
+       clk_disable_unprepare(gi2c->core_clk);
        ret = geni_se_resources_off(&gi2c->se);
        if (ret) {
                dev_err(dev, "Error turning off resources %d\n", ret);
@@ -932,6 +970,8 @@ static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
                gi2c->suspended = 1;
        }
 
+       clk_disable_unprepare(gi2c->core_clk);
+
        return geni_icc_disable(&gi2c->se);
 }
 
@@ -944,6 +984,10 @@ static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
        if (ret)
                return ret;
 
+       ret = clk_prepare_enable(gi2c->core_clk);
+       if (ret)
+               return ret;
+
        ret = geni_se_resources_on(&gi2c->se);
        if (ret)
                return ret;