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![Simon Glass](/assets/img/avatar_default.png)
This construct is quite long-winded. In earlier days it made some sense since auto-allocation was a strange concept. But with driver model now used pretty universally, we can shorten this to 'auto'. This reduces verbosity and makes it easier to read. Coincidentally it also ensures that every declaration is on one line, thus making dtoc's job easier. Signed-off-by: Simon Glass <sjg@chromium.org>
108 lines
2.7 KiB
C
108 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* 64-bit Periodic Interval Timer driver
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*
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* Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
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*
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* Author: Claudiu Beznea <claudiu.beznea@microchip.com>
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*/
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#include <common.h>
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#include <clk.h>
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#include <dm.h>
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#include <timer.h>
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#include <asm/io.h>
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#define MCHP_PIT64B_CR 0x00 /* Control Register */
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#define MCHP_PIT64B_CR_START BIT(0)
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#define MCHP_PIT64B_CR_SWRST BIT(8)
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#define MCHP_PIT64B_MR 0x04 /* Mode Register */
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#define MCHP_PIT64B_MR_CONT BIT(0)
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#define MCHP_PIT64B_LSB_PR 0x08 /* LSB Period Register */
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#define MCHP_PIT64B_MSB_PR 0x0C /* MSB Period Register */
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#define MCHP_PIT64B_TLSBR 0x20 /* Timer LSB Register */
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#define MCHP_PIT64B_TMSBR 0x24 /* Timer MSB Register */
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struct mchp_pit64b_priv {
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void __iomem *base;
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};
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static u64 mchp_pit64b_get_count(struct udevice *dev)
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{
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struct mchp_pit64b_priv *priv = dev_get_priv(dev);
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u32 lsb = readl(priv->base + MCHP_PIT64B_TLSBR);
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u32 msb = readl(priv->base + MCHP_PIT64B_TMSBR);
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return ((u64)msb << 32) | lsb;
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}
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static int mchp_pit64b_probe(struct udevice *dev)
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{
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struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
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struct mchp_pit64b_priv *priv = dev_get_priv(dev);
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struct clk clk;
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ulong rate;
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int ret;
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priv->base = dev_read_addr_ptr(dev);
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if (IS_ERR(priv->base))
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return PTR_ERR(priv->base);
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ret = clk_get_by_index(dev, 0, &clk);
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if (ret)
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return ret;
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ret = clk_enable(&clk);
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if (ret)
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return ret;
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rate = clk_get_rate(&clk);
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if (!rate) {
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clk_disable(&clk);
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return -ENOTSUPP;
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}
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/* Reset the timer in case it was used by previous bootloaders. */
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writel(MCHP_PIT64B_CR_SWRST, priv->base + MCHP_PIT64B_CR);
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/*
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* Use highest prescaller (for a peripheral clock running at 200MHz
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* this will lead to the timer running at 12.5MHz) and continuous mode.
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*/
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writel((15 << 8) | MCHP_PIT64B_MR_CONT, priv->base + MCHP_PIT64B_MR);
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uc_priv->clock_rate = rate / 16;
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/*
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* Simulate free running counter by setting max values to period
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* registers.
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*/
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writel(~0UL, priv->base + MCHP_PIT64B_MSB_PR);
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writel(~0UL, priv->base + MCHP_PIT64B_LSB_PR);
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/* Start the timer. */
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writel(MCHP_PIT64B_CR_START, priv->base + MCHP_PIT64B_CR);
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return 0;
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}
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static const struct timer_ops mchp_pit64b_ops = {
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.get_count = mchp_pit64b_get_count,
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};
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static const struct udevice_id mchp_pit64b_ids[] = {
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{ .compatible = "microchip,sam9x60-pit64b", },
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{ .compatible = "microchip,sama7g5-pit64b", },
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{ }
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};
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U_BOOT_DRIVER(mchp_pit64b) = {
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.name = "mchp-pit64b",
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.id = UCLASS_TIMER,
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.of_match = mchp_pit64b_ids,
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.priv_auto = sizeof(struct mchp_pit64b_priv),
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.probe = mchp_pit64b_probe,
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.ops = &mchp_pit64b_ops,
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.flags = DM_FLAG_PRE_RELOC,
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};
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