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-rw-r--r--drivers/clk/hisilicon/clk-hi3660-stub.c178
1 files changed, 178 insertions, 0 deletions
diff --git a/drivers/clk/hisilicon/clk-hi3660-stub.c b/drivers/clk/hisilicon/clk-hi3660-stub.c
new file mode 100644
index 000000000..3a653d54b
--- /dev/null
+++ b/drivers/clk/hisilicon/clk-hi3660-stub.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hisilicon clock driver
+ *
+ * Copyright (c) 2013-2017 Hisilicon Limited.
+ * Copyright (c) 2017 Linaro Limited.
+ *
+ * Author: Kai Zhao <zhaokai1@hisilicon.com>
+ * Tao Wang <kevin.wangtao@hisilicon.com>
+ * Leo Yan <leo.yan@linaro.org>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/clock/hi3660-clock.h>
+
+#define HI3660_STUB_CLOCK_DATA (0x70)
+#define MHZ (1000 * 1000)
+
+#define DEFINE_CLK_STUB(_id, _cmd, _name) \
+ { \
+ .id = (_id), \
+ .cmd = (_cmd), \
+ .hw.init = &(struct clk_init_data) { \
+ .name = #_name, \
+ .ops = &hi3660_stub_clk_ops, \
+ .num_parents = 0, \
+ .flags = CLK_GET_RATE_NOCACHE, \
+ }, \
+ },
+
+#define to_stub_clk(_hw) container_of(_hw, struct hi3660_stub_clk, hw)
+
+struct hi3660_stub_clk_chan {
+ struct mbox_client cl;
+ struct mbox_chan *mbox;
+};
+
+struct hi3660_stub_clk {
+ unsigned int id;
+ struct clk_hw hw;
+ unsigned int cmd;
+ unsigned int msg[8];
+ unsigned int rate;
+};
+
+static void __iomem *freq_reg;
+static struct hi3660_stub_clk_chan stub_clk_chan;
+
+static unsigned long hi3660_stub_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
+
+ /*
+ * LPM3 writes back the CPU frequency in shared SRAM so read
+ * back the frequency.
+ */
+ stub_clk->rate = readl(freq_reg + (stub_clk->id << 2)) * MHZ;
+ return stub_clk->rate;
+}
+
+static long hi3660_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ /*
+ * LPM3 handles rate rounding so just return whatever
+ * rate is requested.
+ */
+ return rate;
+}
+
+static int hi3660_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct hi3660_stub_clk *stub_clk = to_stub_clk(hw);
+
+ stub_clk->msg[0] = stub_clk->cmd;
+ stub_clk->msg[1] = rate / MHZ;
+
+ dev_dbg(stub_clk_chan.cl.dev, "set rate msg[0]=0x%x msg[1]=0x%x\n",
+ stub_clk->msg[0], stub_clk->msg[1]);
+
+ mbox_send_message(stub_clk_chan.mbox, stub_clk->msg);
+ mbox_client_txdone(stub_clk_chan.mbox, 0);
+
+ stub_clk->rate = rate;
+ return 0;
+}
+
+static const struct clk_ops hi3660_stub_clk_ops = {
+ .recalc_rate = hi3660_stub_clk_recalc_rate,
+ .round_rate = hi3660_stub_clk_round_rate,
+ .set_rate = hi3660_stub_clk_set_rate,
+};
+
+static struct hi3660_stub_clk hi3660_stub_clks[HI3660_CLK_STUB_NUM] = {
+ DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER0, 0x0001030A, "cpu-cluster.0")
+ DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER1, 0x0002030A, "cpu-cluster.1")
+ DEFINE_CLK_STUB(HI3660_CLK_STUB_GPU, 0x0003030A, "clk-g3d")
+ DEFINE_CLK_STUB(HI3660_CLK_STUB_DDR, 0x00040309, "clk-ddrc")
+};
+
+static struct clk_hw *hi3660_stub_clk_hw_get(struct of_phandle_args *clkspec,
+ void *data)
+{
+ unsigned int idx = clkspec->args[0];
+
+ if (idx >= HI3660_CLK_STUB_NUM) {
+ pr_err("%s: invalid index %u\n", __func__, idx);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return &hi3660_stub_clks[idx].hw;
+}
+
+static int hi3660_stub_clk_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ unsigned int i;
+ int ret;
+
+ /* Use mailbox client without blocking */
+ stub_clk_chan.cl.dev = dev;
+ stub_clk_chan.cl.tx_done = NULL;
+ stub_clk_chan.cl.tx_block = false;
+ stub_clk_chan.cl.knows_txdone = false;
+
+ /* Allocate mailbox channel */
+ stub_clk_chan.mbox = mbox_request_channel(&stub_clk_chan.cl, 0);
+ if (IS_ERR(stub_clk_chan.mbox))
+ return PTR_ERR(stub_clk_chan.mbox);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -EINVAL;
+ freq_reg = devm_ioremap(dev, res->start, resource_size(res));
+ if (!freq_reg)
+ return -ENOMEM;
+
+ freq_reg += HI3660_STUB_CLOCK_DATA;
+
+ for (i = 0; i < HI3660_CLK_STUB_NUM; i++) {
+ ret = devm_clk_hw_register(&pdev->dev, &hi3660_stub_clks[i].hw);
+ if (ret)
+ return ret;
+ }
+
+ return devm_of_clk_add_hw_provider(&pdev->dev, hi3660_stub_clk_hw_get,
+ hi3660_stub_clks);
+}
+
+static const struct of_device_id hi3660_stub_clk_of_match[] = {
+ { .compatible = "hisilicon,hi3660-stub-clk", },
+ {}
+};
+
+static struct platform_driver hi3660_stub_clk_driver = {
+ .probe = hi3660_stub_clk_probe,
+ .driver = {
+ .name = "hi3660-stub-clk",
+ .of_match_table = hi3660_stub_clk_of_match,
+ },
+};
+
+static int __init hi3660_stub_clk_init(void)
+{
+ return platform_driver_register(&hi3660_stub_clk_driver);
+}
+subsys_initcall(hi3660_stub_clk_init);