Hello Oleksandr,

On Sat, Sep 2, 2017 at 1:36 AM, Oleksandr Shamray
[off-list ref] wrote:

Driver adds support of Aspeed 2500/2400 series SOC JTAG master controller.

Looks good. I have some small comments. The most important is the
compatible string.

You could add this if you want:

 depends ARCH_ASPEED || COMPILE_TEST

+       ---help---
+         This provides a support for Aspeed JTAG device, equipped on
+         Aspeed SoC 24xx and 25xx families. Drivers allows programming
+         of hardware devices, connected to SoC through the JTAG interface.
+

+
+static char *end_status_str[] = {"idle", "ir pause", "drpause"};
+
+static u32 aspeed_jtag_read(struct aspeed_jtag *aspeed_jtag, u32 reg)
+{
+       return readl(aspeed_jtag->reg_base + reg);
+}
+
+static void
+aspeed_jtag_write(struct aspeed_jtag *aspeed_jtag, u32 val, u32 reg)
+{
+       writel(val, aspeed_jtag->reg_base + reg);
+}
+
+static int aspeed_jtag_freq_set(struct jtag *jtag, __u32 freq)

What's the __u32 for (the __ part)?

+{
+       struct aspeed_jtag *aspeed_jtag = jtag_priv(jtag);
+       unsigned long apb_frq;
+       u32 tck_val;
+       u16 div;
+
+       apb_frq = clk_get_rate(aspeed_jtag->pclk);
+       div = (apb_frq % freq == 0) ? (apb_frq / freq) - 1 : (apb_frq / freq);
+       tck_val = aspeed_jtag_read(aspeed_jtag, ASPEED_JTAG_TCK);
+       aspeed_jtag_write(aspeed_jtag,
+                         (tck_val & ASPEED_JTAG_TCK_DIVISOR_MASK) | div,
+                         ASPEED_JTAG_TCK);
+       return 0;
+}

+
+static int aspeed_jtag_xfer(struct jtag *jtag, struct jtag_xfer *xfer)
+{
+       static const char sm_update_shiftir[] = {1, 1, 0, 0};
+       static const char sm_update_shiftdr[] = {1, 0, 0};
+       static const char sm_pause_idle[] = {1, 1, 0};
+       static const char sm_pause_update[] = {1, 1};

Nit: I was confused by the char, perhaps u8?

+int aspeed_jtag_init(struct platform_device *pdev,
+                    struct aspeed_jtag *aspeed_jtag)
+{
+       struct resource *res;
+       int err;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       aspeed_jtag->reg_base = devm_ioremap_resource(aspeed_jtag->dev, res);
+       if (IS_ERR(aspeed_jtag->reg_base)) {
+               err = -ENOMEM;
+               goto out_region;

Can you just return here?

+       }
+
+       aspeed_jtag->pclk = devm_clk_get(aspeed_jtag->dev, NULL);
+       if (IS_ERR(aspeed_jtag->pclk)) {
+               dev_err(aspeed_jtag->dev, "devm_clk_get failed\n");
+               return PTR_ERR(aspeed_jtag->pclk);
+       }
+
+       clk_prepare_enable(aspeed_jtag->pclk);
+
+       aspeed_jtag->irq = platform_get_irq(pdev, 0);
+       if (aspeed_jtag->irq < 0) {
+               dev_err(aspeed_jtag->dev, "no irq specified\n");
+               err = -ENOENT;
+               goto out_region;
+       }
+
+       /* Enable clock */
+       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_CTL_ENG_EN |
+                         ASPEED_JTAG_CTL_ENG_OUT_EN, ASPEED_JTAG_CTRL);
+       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_SW_MODE_EN |
+                         ASPEED_JTAG_SW_MODE_TDIO, ASPEED_JTAG_SW);
+
+       err = devm_request_irq(aspeed_jtag->dev, aspeed_jtag->irq,
+                              aspeed_jtag_interrupt, 0,
+                              "aspeed-jtag", aspeed_jtag);
+       if (err) {
+               dev_err(aspeed_jtag->dev, "aspeed_jtag unable to get IRQ");
+               goto out_region;
+       }

Can we grab the IRQ before enabling the clock? If not, we should
disable the clock in the error path.

+       dev_dbg(&pdev->dev, "aspeed_jtag:IRQ %d.\n", aspeed_jtag->irq);
+
+       aspeed_jtag_write(aspeed_jtag, ASPEED_JTAG_ISR_INST_PAUSE |
+                         ASPEED_JTAG_ISR_INST_COMPLETE |
+                         ASPEED_JTAG_ISR_DATA_PAUSE |
+                         ASPEED_JTAG_ISR_DATA_COMPLETE |
+                         ASPEED_JTAG_ISR_INST_PAUSE_EN |
+                         ASPEED_JTAG_ISR_INST_COMPLETE_EN |
+                         ASPEED_JTAG_ISR_DATA_PAUSE_EN |
+                         ASPEED_JTAG_ISR_DATA_COMPLETE_EN,
+                         ASPEED_JTAG_ISR);
+
+       aspeed_jtag->flag = 0;
+       init_waitqueue_head(&aspeed_jtag->jtag_wq);
+       return 0;
+
+out_region:
+       release_mem_region(res->start, resource_size(res));

I don't think this is necessary.

+       return err;
+}
+
+int aspeed_jtag_deinit(struct platform_device *pdev,
+                      struct aspeed_jtag *aspeed_jtag)
+{
+       aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_ISR);
+       devm_free_irq(aspeed_jtag->dev, aspeed_jtag->irq, aspeed_jtag);

The IRQ freeing happen automatically thanks to devm.

+       /* Disabe clock */

Disable

+       aspeed_jtag_write(aspeed_jtag, 0, ASPEED_JTAG_CTRL);
+       clk_disable_unprepare(aspeed_jtag->pclk);
+       return 0;
+}
+
+static const struct jtag_ops aspeed_jtag_ops = {
+       .freq_get = aspeed_jtag_freq_get,
+       .freq_set = aspeed_jtag_freq_set,
+       .status_get = aspeed_jtag_status_get,
+       .idle = aspeed_jtag_idle,
+       .xfer = aspeed_jtag_xfer
+};
+
+static int aspeed_jtag_probe(struct platform_device *pdev)
+{
+       struct aspeed_jtag *aspeed_jtag;
+       struct jtag *jtag;
+       int err;
+
+       if (!of_device_is_compatible(pdev->dev.of_node, "aspeed,aspeed-jtag"))
+               return -ENOMEM;
+
+       jtag = jtag_alloc(sizeof(*aspeed_jtag), &aspeed_jtag_ops);
+       if (!jtag)
+               return -ENODEV;
+
+       platform_set_drvdata(pdev, jtag);
+       aspeed_jtag = jtag_priv(jtag);
+       aspeed_jtag->dev = &pdev->dev;
+
+       /* Initialize device*/
+       err = aspeed_jtag_init(pdev, aspeed_jtag);
+       if (err)
+               goto err_jtag_init;
+
+       /* Initialize JTAG core structure*/
+       err = jtag_register(jtag);
+       if (err)
+               goto err_jtag_register;
+
+       return 0;
+
+err_jtag_register:
+       aspeed_jtag_deinit(pdev, aspeed_jtag);
+err_jtag_init:
+       jtag_free(jtag);
+       return err;
+}
+
+static int aspeed_jtag_remove(struct platform_device *pdev)
+{
+       struct jtag *jtag;
+
+       jtag = platform_get_drvdata(pdev);
+       aspeed_jtag_deinit(pdev, jtag_priv(jtag));
+       jtag_unregister(jtag);
+       jtag_free(jtag);
+       return 0;
+}
+
+static const struct of_device_id aspeed_jtag_of_match[] = {
+       { .compatible = "aspeed,aspeed2400-jtag", },
+       { .compatible = "aspeed,aspeed2500-jtag", },

The convention is to use ast2500 for our compatible strings, so these should be:

 aspeed,ast2500-jtag
 aspeed,ast2400-jtag

Cheers,

Joel